Ontario Nuclear News
Article
Most Excellent! OPG has cleared itself of any sloppiness regarding its own nuclear plants. This bit of good news is bound to be repeated by all Canadian news outlets, as they need something after the royal wedding. :)
Friday, April 29, 2011
Milking Old Nuclear Plants
Article
Exelon has turned its back on new nuclear power projects, for the balance of this decade, at least, because the power output from the multibillion-dollar new plants could not compete with natural gas-fired power plants in the absence of a carbon price. Instead, Exelon will channel most of its capacity expansion into gas generation, its officials say.
But Exelon has also embarked on a costly plan to increase the output of its existing nuclear plants through uprates achieved by expanding reactor capacity. The uprates would add as much as 1,500 megawatts of new generation if the Nuclear Regulatory Commission (NRC) approves the projects. It is also expected to seek 20-year operating license renewals on the remaining reactors that have not yet been cleared for the license extensions.
They are uprating these horrible old plants, while keeping all the backups the same. As shown by the recent tornadoes in Alabama, these plants fall back onto emergency systems all the time. This is not good, and is like the window-washer constantly using his backup rope. When you constantly fall to a single backup, there is no backup to the backup. It just takes one more thing (like an earthquake), and that backup is gone. With uprated BWR's (Japan version), you only got an hour before fuel meltdown and explosions.
Really, if you just lose external power, the plant should be able to reduce power, and just live on it's own turbine, essentially forever. The diesel backups should just be extreme backups, because there is nothing else.
Exelon has turned its back on new nuclear power projects, for the balance of this decade, at least, because the power output from the multibillion-dollar new plants could not compete with natural gas-fired power plants in the absence of a carbon price. Instead, Exelon will channel most of its capacity expansion into gas generation, its officials say.
But Exelon has also embarked on a costly plan to increase the output of its existing nuclear plants through uprates achieved by expanding reactor capacity. The uprates would add as much as 1,500 megawatts of new generation if the Nuclear Regulatory Commission (NRC) approves the projects. It is also expected to seek 20-year operating license renewals on the remaining reactors that have not yet been cleared for the license extensions.
They are uprating these horrible old plants, while keeping all the backups the same. As shown by the recent tornadoes in Alabama, these plants fall back onto emergency systems all the time. This is not good, and is like the window-washer constantly using his backup rope. When you constantly fall to a single backup, there is no backup to the backup. It just takes one more thing (like an earthquake), and that backup is gone. With uprated BWR's (Japan version), you only got an hour before fuel meltdown and explosions.
Really, if you just lose external power, the plant should be able to reduce power, and just live on it's own turbine, essentially forever. The diesel backups should just be extreme backups, because there is nothing else.
Wednesday, April 27, 2011
New Madrid Has Not Shut Down
Article
So, it looks like the USGS was worried about that guy who associates no gps signals with no hazard. The got some 'independent' panel to confirm their view on the matter. The panel concludes:
The New Madrid Seismic Zone represents a significant hazard for large earthquakes that would cause widespread damage.
This hazard must be accounted for in urban planning and development.
The panel does not support the view of some individuals that the region has “shut down” in its production of large earthquakes.
The current version of the USGS national seismic hazard maps are a good estimate of the overall hazard posed by the New Madrid Seismic Zone and should continue to be used until the next revision of the maps replace them in 2013.
Additional research could lower remaining uncertainties and thus potentially lower the potential hazard in future maps.
So, it looks like the USGS was worried about that guy who associates no gps signals with no hazard. The got some 'independent' panel to confirm their view on the matter. The panel concludes:
The New Madrid Seismic Zone represents a significant hazard for large earthquakes that would cause widespread damage.
This hazard must be accounted for in urban planning and development.
The panel does not support the view of some individuals that the region has “shut down” in its production of large earthquakes.
The current version of the USGS national seismic hazard maps are a good estimate of the overall hazard posed by the New Madrid Seismic Zone and should continue to be used until the next revision of the maps replace them in 2013.
Additional research could lower remaining uncertainties and thus potentially lower the potential hazard in future maps.
Tuesday, April 26, 2011
Bell Internet Usage Billing Still Wacky
So, this month I have been watching, and I estimate 20-30 Gbytes for the month. And they say I used 70! So now I intend to watch it every day, but suddenly the service isn't available again. The kids are coming home, and I'm going to die with this overbilling, if they keep multiplying things. :)
Bruce Geological Nuclear Waste Documents
I have just finished the main document, which is the safety report. It goes through the whole case, and outlines all the results. The rest of the documents might be more details. I'm slowly putting it in Deepie Brucie.
Strangely enough, I find myself supporting it, if they can sink the shafts without incident, which I don't think they can do. If the shafts are successful, and totally waterproof, then they have entered a decoupled block of rock, which has somehow survived the violent geological history. If they require a huge sump pump, and lots of water is constantly being pumped out, then they have failed, since I don't think this rock is stable when being pumped.
Much like the Niagara Tunnel, the shafts will put them billions over, but they have lots of money, and the tunnel was built after all. For the env. assessment, they underestimate the amount of grout, which is nasty stuff, and produces a lot of carbon pollution in its manufacture.
If we have perfect shafts, then the site is perfect. There is no chance of any leakage, and we'll never notice it, what with all the expected blowups of nuclear plants in the coming decades. :) They are claiming the same grade as a fuel storage site, so take that as you may.
Strangely enough, I find myself supporting it, if they can sink the shafts without incident, which I don't think they can do. If the shafts are successful, and totally waterproof, then they have entered a decoupled block of rock, which has somehow survived the violent geological history. If they require a huge sump pump, and lots of water is constantly being pumped out, then they have failed, since I don't think this rock is stable when being pumped.
Much like the Niagara Tunnel, the shafts will put them billions over, but they have lots of money, and the tunnel was built after all. For the env. assessment, they underestimate the amount of grout, which is nasty stuff, and produces a lot of carbon pollution in its manufacture.
If we have perfect shafts, then the site is perfect. There is no chance of any leakage, and we'll never notice it, what with all the expected blowups of nuclear plants in the coming decades. :) They are claiming the same grade as a fuel storage site, so take that as you may.
Monday, April 25, 2011
Just Another Easter Monday
Wish it were Funday! No earthquakes, or other silliness. I am forced to do what I never wanted to do -- go into those damn Bruce papers. As such, I have started a new site - Deepie Brucie. I wrote a few lines. I expect this to go horribly slowly, and I might need extra pills, so don't check too often.
If any geologist wants to form a Brucie Deepie club, we can get t-shirts, and you can make up a secret Google account. I'll give access if you want to do a chapter. Don't use your real name or you'll never work in this town again!
If any geologist wants to form a Brucie Deepie club, we can get t-shirts, and you can make up a secret Google account. I'll give access if you want to do a chapter. Don't use your real name or you'll never work in this town again!
Sunday, April 24, 2011
Even Houston does a shake out
Article
Ok, virtually, no chance of an earthquake here, but they are willing to do something. Toronto has a major chance, and it will never be acknowledged.
Ok, virtually, no chance of an earthquake here, but they are willing to do something. Toronto has a major chance, and it will never be acknowledged.
Friday, April 22, 2011
Flywheels and Earthquakes
Article
This just struck my fancy. I would expect some pretty dramatic interaction in Burlington, should an earthquake hit a flywheel farm. These are giant gyroscopes, and I wonder what would happen, but my general thought is that they would rip anchors out of concrete. Such fun!
This just struck my fancy. I would expect some pretty dramatic interaction in Burlington, should an earthquake hit a flywheel farm. These are giant gyroscopes, and I wonder what would happen, but my general thought is that they would rip anchors out of concrete. Such fun!
Thursday, April 21, 2011
Earthquake-wise Victoria and Vancouver are not that bad
Got a note from somebody in Victoria, who had the earthquake jitters. You can see out in the ocean, the great Cascadia Subduction Zone. Really, this poses no great threat to Victoria and Vancouver. We can probably only expect 10 cm/s PGV to these cities from an M9. No tsunami can hit them, but you must expect some sort of water rise in the channels, but I think the main water surge will just bounce off the rocks, and back into the ocean.
As with almost all cities, with beautiful earthquake scenery, the biggest threat is the urban M7 earthquake, just like Kobe Japan. This is not something to get the jitters over, and is not a good reason to move to Toronto, which is under the same threat. You have to do the usual things: check your foundation, secure heavy objects, have an emergency kit, etc.
New Nuclear Going for a Song
Article
“The tragic nuclear incident in Japan has introduced multiple uncertainties around new nuclear development in the United States which have had the effect of dramatically reducing the probability that STP 3&4 can be successfully developed in a timely fashion,” NRG President and CEO David Crane said.
Well, with the US dollar tanking, it is time to do some serious cross-border shopping! Almost all the nuclear plants are being canceled, but most of them had pre-ordered the heavy steel. What bargains to be had!
ps. the above was pleasant fantasy. I really don't want to sink into the reality of our situation.
“The tragic nuclear incident in Japan has introduced multiple uncertainties around new nuclear development in the United States which have had the effect of dramatically reducing the probability that STP 3&4 can be successfully developed in a timely fashion,” NRG President and CEO David Crane said.
Well, with the US dollar tanking, it is time to do some serious cross-border shopping! Almost all the nuclear plants are being canceled, but most of them had pre-ordered the heavy steel. What bargains to be had!
ps. the above was pleasant fantasy. I really don't want to sink into the reality of our situation.
Wednesday, April 20, 2011
CNSC task force without geology or seismic
Press Release
Do you know that Tokyo Power knew the exact moment when the inner vault ruptured? It happened very shortly after the cooling was lost. They were culturally incapable of telling anyone. Some goes for here.
Anyway, all hail the great task force!
Do you know that Tokyo Power knew the exact moment when the inner vault ruptured? It happened very shortly after the cooling was lost. They were culturally incapable of telling anyone. Some goes for here.
Anyway, all hail the great task force!
Bruce Nuclear Waste Thing Releases Documents
Link
Good grief! I didn't see it! No press releases. No great speeches with tiny pieces of rock! I just saw a glancing reference to it. No wonder there was a single press article!
So, it's just a tad late. Now that it is here, I shall be totally glad to forget it. These things are very depressing to me.
I am surprised that OPG is doing this. I always thought it was those other waste people who are joined at the hip. In Austen-speak: I shan't make fun of them; they are poor sport indeed.
ps - Notice the date!
Good grief! I didn't see it! No press releases. No great speeches with tiny pieces of rock! I just saw a glancing reference to it. No wonder there was a single press article!
So, it's just a tad late. Now that it is here, I shall be totally glad to forget it. These things are very depressing to me.
I am surprised that OPG is doing this. I always thought it was those other waste people who are joined at the hip. In Austen-speak: I shan't make fun of them; they are poor sport indeed.
ps - Notice the date!
Pickering Nuclear Plant - The Intake
Article
This nice article reminds me of the intake. It is a most horrible thing, sucking in everything. You can even see with Google Maps that it is right in the littoral drift, which is a permanent river of silt. We did geophysics out in the lake, and you could see these giant Sahara-like dunes of silt migrating along the bottom.
As I have written in my fanciful earthquake scenario, these mountains of silt will become greatly disturbed in an earthquake. We will leave it to your imagination.
This nice article reminds me of the intake. It is a most horrible thing, sucking in everything. You can even see with Google Maps that it is right in the littoral drift, which is a permanent river of silt. We did geophysics out in the lake, and you could see these giant Sahara-like dunes of silt migrating along the bottom.
As I have written in my fanciful earthquake scenario, these mountains of silt will become greatly disturbed in an earthquake. We will leave it to your imagination.
Tuesday, April 19, 2011
Geology, Earthquakes, Tsunamis and Nuclear Power Plants
Article
Experts hope Japan has taught the world an important lesson: When it comes to nuclear safety, it's essential to imagine the unimaginable. Looking back 50 years, or even 500, is not enough.
"When you're talking about radioactivity and possibilities of explosions ... you have to look at what is within the realm of possibility," said Jody Bourgeois, a tsunami expert at the University of Washington who was doing research in Japan when the disaster struck. "You should be building it with factors of safety for the maximum possible events."
This is a very good article. When people write like this, they scarcely need me! I've been seeing way too many Jane Austen movies lately, so I shall end with: Isn't it a great diversion to see such foolishness, in the nuclear bosses around us. For what is our purpose in life, then to have our fellows laugh at us, as we laugh at them, in return.
Experts hope Japan has taught the world an important lesson: When it comes to nuclear safety, it's essential to imagine the unimaginable. Looking back 50 years, or even 500, is not enough.
"When you're talking about radioactivity and possibilities of explosions ... you have to look at what is within the realm of possibility," said Jody Bourgeois, a tsunami expert at the University of Washington who was doing research in Japan when the disaster struck. "You should be building it with factors of safety for the maximum possible events."
This is a very good article. When people write like this, they scarcely need me! I've been seeing way too many Jane Austen movies lately, so I shall end with: Isn't it a great diversion to see such foolishness, in the nuclear bosses around us. For what is our purpose in life, then to have our fellows laugh at us, as we laugh at them, in return.
Leakage from the Bruce Nuclear Waste Thing
Article
A little press leakage, despite the best efforts to keep quiet. Maybe they are starting to work towards releasing their report? It's going to be months overdue.
As always, we have the top people making grand geological statements. Will they bring out their tiny piece of limestone again?
A little press leakage, despite the best efforts to keep quiet. Maybe they are starting to work towards releasing their report? It's going to be months overdue.
As always, we have the top people making grand geological statements. Will they bring out their tiny piece of limestone again?
Monday, April 18, 2011
US nuclear plants are significantly uprated
Article
Well, this is fascinating. The uprated US plants ran into some of the same dynamic problems as Bruce and Darlington. Bascially, if you increase water flow you may hit non-linearities and feedback loops. Nothing ever as bad as the Darlington Water Laser, but bad enough. Still, these things can be fixed.
I can't really comment here, but it is always possible to reduce a crude safety factor, if you do more analysis and measurement. Hopefully, this is what they are doing (Ha!).
Well, this is fascinating. The uprated US plants ran into some of the same dynamic problems as Bruce and Darlington. Bascially, if you increase water flow you may hit non-linearities and feedback loops. Nothing ever as bad as the Darlington Water Laser, but bad enough. Still, these things can be fixed.
I can't really comment here, but it is always possible to reduce a crude safety factor, if you do more analysis and measurement. Hopefully, this is what they are doing (Ha!).
Earthquake Near New Zealand
This is a totally meaningless earthquake, but I just wrote this for the graphic. This is the Google map from the USGS earthquake site. I was also looking at this map with the recent Australian earthquake. That whole teapot shape is the Australian plate, so both the Christchurch and Barrier Reef earthquakes can be considered to be Intraplate earthquakes. (I started that Wikipedia article!). This earthquake is right on the edge of the plate, and is a standard interplate earthquake. Much like Japan, we would expect that whole section to rip in a giant M9plus one day.
If they can find lowland marshes in Australia, it would be interesting to find the frequency of large tsunamis hitting that coast. Probably about every 500 years.
Saturday, April 16, 2011
Geology - Columbia Basin 3-D Map
Reference
Who says the USGS never does anything? This is a marvelous toy for a rainy day! Especially since it's all to do with groundwater. You can look at well logs and make cross-sections all day! I think the subject is vastly boring, but the technique is interesting.
Who says the USGS never does anything? This is a marvelous toy for a rainy day! Especially since it's all to do with groundwater. You can look at well logs and make cross-sections all day! I think the subject is vastly boring, but the technique is interesting.
Friday, April 15, 2011
Splitting Hairs in California Doesn't Work
Article
“We recognize that many in the public have called for this research to be completed before the NRC renews the plant’s licenses,” said Conway. “We are being responsive to this concern by seeking to expeditiously complete the 3-D seismic studies and provide those findings to the commission and other interested parties so that they may have added assurance of the plant’s seismic integrity.”
It appears to be in their interest to delay licensing. Oh well, that's politics! If there are any lessons from Japan, it's that this attempt at micro-zoning a very bad area does not work! You have to look at the whole picture and assume it's all bad. California is more fixated at sub-zoning than Japan! They want to assign significance to a single fault, and thoroughly examined it with a complex 3-D seismic survey! Oh, please! California is riddled with a zillion faults, and it is useless to try and sub-divide the seismic hazard. That didn't work in Japan, and it won't work in California, since an M7 right under a city or plant is as bad as it gets, and these things are totally unpredictable.
But it gives a lot of money to California seismic nit-pickers. Wish I could get that job...
“We recognize that many in the public have called for this research to be completed before the NRC renews the plant’s licenses,” said Conway. “We are being responsive to this concern by seeking to expeditiously complete the 3-D seismic studies and provide those findings to the commission and other interested parties so that they may have added assurance of the plant’s seismic integrity.”
It appears to be in their interest to delay licensing. Oh well, that's politics! If there are any lessons from Japan, it's that this attempt at micro-zoning a very bad area does not work! You have to look at the whole picture and assume it's all bad. California is more fixated at sub-zoning than Japan! They want to assign significance to a single fault, and thoroughly examined it with a complex 3-D seismic survey! Oh, please! California is riddled with a zillion faults, and it is useless to try and sub-divide the seismic hazard. That didn't work in Japan, and it won't work in California, since an M7 right under a city or plant is as bad as it gets, and these things are totally unpredictable.
But it gives a lot of money to California seismic nit-pickers. Wish I could get that job...
New Madrid Earthquake - Still at M7.0
Article
This is another paper by Susan Hough, pushing down the magnitudes of the New Madrid earthquake sequence.
According to The Commercial Appeal newspaper, the paper by Susan E. Hough -- a research seismologist with the U.S. Geological Survey -- says new reviews by independent experts put the magnitude of the three main earthquakes between Dec. 16, 1811, and Feb. 7, 1812, at a maximum of about 7.0.
If you look at the seismicity map for this area, I consider that most of these earthquakes are the aftershocks of the 1811 sequence. That puts the cross-thrust at 40 km, and the shear wing at 80 km. An M7.0 should be about 30 km (about the length of the Hamilton fault). Thus, I think we should give them maybe, an M7.2 ??
But, really, this is nit-picking. The real damage comes from those very soft soils, which I think can amplify more than Christchurch! If you have a basin with a basin, such as Mexico City, then the amplifications go well beyond a factor of 10, and approach a factor of 100. Plus we must expect some directivity pulses, due to super-shear fault rupture. All in all, we might get PGV's of up to 1 m/s, which will destroy anything. The exact magnitude of the earthquake doesn't matter at all, since ground motions saturate at M7.0 anyway. Instead of 30 km for an M7, we just get 300 km for an M8.
ps. looks like they stopped the secret injection at Arkansas, which was an ideal miniature of New Madrid.
This is another paper by Susan Hough, pushing down the magnitudes of the New Madrid earthquake sequence.
According to The Commercial Appeal newspaper, the paper by Susan E. Hough -- a research seismologist with the U.S. Geological Survey -- says new reviews by independent experts put the magnitude of the three main earthquakes between Dec. 16, 1811, and Feb. 7, 1812, at a maximum of about 7.0.
If you look at the seismicity map for this area, I consider that most of these earthquakes are the aftershocks of the 1811 sequence. That puts the cross-thrust at 40 km, and the shear wing at 80 km. An M7.0 should be about 30 km (about the length of the Hamilton fault). Thus, I think we should give them maybe, an M7.2 ??
But, really, this is nit-picking. The real damage comes from those very soft soils, which I think can amplify more than Christchurch! If you have a basin with a basin, such as Mexico City, then the amplifications go well beyond a factor of 10, and approach a factor of 100. Plus we must expect some directivity pulses, due to super-shear fault rupture. All in all, we might get PGV's of up to 1 m/s, which will destroy anything. The exact magnitude of the earthquake doesn't matter at all, since ground motions saturate at M7.0 anyway. Instead of 30 km for an M7, we just get 300 km for an M8.
ps. looks like they stopped the secret injection at Arkansas, which was an ideal miniature of New Madrid.
Wednesday, April 13, 2011
Niagara Tunnel Breakthrough Actually Purposely Scheduled for Friday the 13th
April 7th 2011 -
OPG has stated in a media release issued today that the date of the final break-out of the 14.4 meter diameter TBM named "Big Becky" will occur on Friday May 13th 2011. The TBM remains at 10,136 meters (33,254 feet) at an elevation of 137 meters. This finale will bring to an official end the mining phase of the Niagara Tunnel Project construction. The breakout will occur at 10,143.026 meters. The final push will be 1.5 meters
The tunnel ends at Station 10143 meters at the Intake Structure, a few meters have been excavated by drill and blast. Difference between 10143 meters and 10158 meters is due to the alignment change. Final push is about 1.5 meters.
April 3rd 2011 -
The TBM is at 10,136 meters (33,254 feet) at an elevation of 137 meters. The TBM has stopped mining until the official Breakthrough Ceremony. Work in the tunnel continues. A ventilation bulkhead is being constructed in the tunnel behind the TBM. This is to prevent the loss of air pressure inside the tunnel following the breakthrough. Parts of the TBM that are unnecessary for the final breakthrough continue to be dismantled and removed.
Wow. So, it's just sitting there, ready for the big show. Fireworks? They have to build a big air curtain so that there isn't a giant fart when it breaks through. I love show business!
OPG has stated in a media release issued today that the date of the final break-out of the 14.4 meter diameter TBM named "Big Becky" will occur on Friday May 13th 2011. The TBM remains at 10,136 meters (33,254 feet) at an elevation of 137 meters. This finale will bring to an official end the mining phase of the Niagara Tunnel Project construction. The breakout will occur at 10,143.026 meters. The final push will be 1.5 meters
The tunnel ends at Station 10143 meters at the Intake Structure, a few meters have been excavated by drill and blast. Difference between 10143 meters and 10158 meters is due to the alignment change. Final push is about 1.5 meters.
April 3rd 2011 -
The TBM is at 10,136 meters (33,254 feet) at an elevation of 137 meters. The TBM has stopped mining until the official Breakthrough Ceremony. Work in the tunnel continues. A ventilation bulkhead is being constructed in the tunnel behind the TBM. This is to prevent the loss of air pressure inside the tunnel following the breakthrough. Parts of the TBM that are unnecessary for the final breakthrough continue to be dismantled and removed.
Wow. So, it's just sitting there, ready for the big show. Fireworks? They have to build a big air curtain so that there isn't a giant fart when it breaks through. I love show business!
Japan Earthquake Geology - It's All Bad
Article
So, this guy says they should stop nitpicking seismic hazard in Japan, and declare it all nine-able. I think that would be ok, as long as you take ground conditions into account.
In this article is the big news (to me) that the dang backup generators were in the basement! I kept thinking they were outside, and why couldn't they be restarted? Unbelievable.
So, this guy says they should stop nitpicking seismic hazard in Japan, and declare it all nine-able. I think that would be ok, as long as you take ground conditions into account.
In this article is the big news (to me) that the dang backup generators were in the basement! I kept thinking they were outside, and why couldn't they be restarted? Unbelievable.
Geology - San Onofre Geology and Seismic Study Now $64 million
Article
Ok, that might well be ridiculous. I'm only asking for a few million from OPG, and the new nuclear station. I really don't think you can squeeze that much more information from over-studied California, but here in Ontario, a little goes a long way!
Ok, that might well be ridiculous. I'm only asking for a few million from OPG, and the new nuclear station. I really don't think you can squeeze that much more information from over-studied California, but here in Ontario, a little goes a long way!
Tuesday, April 12, 2011
Nuclear Waste and Earthquake Novel
Article
The plot: A deadly earthquake rips through the Hanford nuclear reservation, erupting a graveyard of radioactive waste and releasing a flood of doom that threatens thousands of Tri-Citians.
Ah, that's what I always wanted to do, a great novel that sets aside reality, and invokes a great disaster. I would have done it for Toronto! Since I have no talent, I went for a blog instead. :) It's up to the readers to decide whether it is fantasy or reality. :)
Basically, I want all the grumpies to think this whole blog is wild fantasy, and the happy, witty person can see the truth shine through....
The plot: A deadly earthquake rips through the Hanford nuclear reservation, erupting a graveyard of radioactive waste and releasing a flood of doom that threatens thousands of Tri-Citians.
Ah, that's what I always wanted to do, a great novel that sets aside reality, and invokes a great disaster. I would have done it for Toronto! Since I have no talent, I went for a blog instead. :) It's up to the readers to decide whether it is fantasy or reality. :)
Basically, I want all the grumpies to think this whole blog is wild fantasy, and the happy, witty person can see the truth shine through....
Monday, April 11, 2011
Diablo Canyon going for new earthquake study
Article
I just thought this was interesting. Maybe there will be a run on quake study people. Perhaps this will catch on in Ontario? If enough people do these studies, they will laugh at those who rely on 20 years of recorded seismicity and 200 years of poor reporting by ancient newspapers.
I just thought this was interesting. Maybe there will be a run on quake study people. Perhaps this will catch on in Ontario? If enough people do these studies, they will laugh at those who rely on 20 years of recorded seismicity and 200 years of poor reporting by ancient newspapers.
Geology - Japanese Run on Sturdy Tables
Article
Susan Hough, a USGS geologist who has written extensively on the subject of earthquake predictions, sounded a skeptical note when asked about the increased risk of a big quake: “Big earthquakes don’t cascade like dominoes, bang bang bang. At least not commonly. So I think the maps showing bright red bull’s eyes of increased stress may be more alarming than they should be.”
After the March 11 quake, Stein prepared a letter, authorized by his superiors, that offered basic advice to American officials in Japan: Carry a whistle, water, power bars, a first-aid kit, flashlight and batteries, work gloves and a trowel for digging people out of debris. Look around for objects that might become lethal missiles in an earthquake. And identify the sturdiest table in the room — and be ready to dive under it when the next big one hits.
It's true, you never see an immediate 'zippering' of adjacent faults. Even the most 'zipperish' fault in Turkey separates the events by decades. So, it really is an open horse race on which world city will get hammered by the next big earthquake. Could be Toronto????
Susan Hough, a USGS geologist who has written extensively on the subject of earthquake predictions, sounded a skeptical note when asked about the increased risk of a big quake: “Big earthquakes don’t cascade like dominoes, bang bang bang. At least not commonly. So I think the maps showing bright red bull’s eyes of increased stress may be more alarming than they should be.”
After the March 11 quake, Stein prepared a letter, authorized by his superiors, that offered basic advice to American officials in Japan: Carry a whistle, water, power bars, a first-aid kit, flashlight and batteries, work gloves and a trowel for digging people out of debris. Look around for objects that might become lethal missiles in an earthquake. And identify the sturdiest table in the room — and be ready to dive under it when the next big one hits.
It's true, you never see an immediate 'zippering' of adjacent faults. Even the most 'zipperish' fault in Turkey separates the events by decades. So, it really is an open horse race on which world city will get hammered by the next big earthquake. Could be Toronto????
Now, Nobody Loves MOX
Article
Plutonium is easy to handle because the radiation it gives off is persistent but relatively weak. The type used in weapons, plutonium 239, has a half-life of 24,000 years and emits alpha rays. They make the plutonium feel warm to the touch but are so feeble that skin easily stops the radiation. If trapped inside the body, though, alpha rays can cause cancer.
Plutonium is the 'puppy dog' of radioactive materials. As with all alpha-emitters, just don't grind it up and have it as a smoothy! You would need to ingest a lot of it to really get up to the horror stories of the greenies. We old people could eat it for breakfast, and I don't know how long it would stay in the body if you were determined to get rid of it. I think the horror stories were derived from the urban myth that John Wayne inhaled a persistent speck of P. into his lungs, and this had an effect over that of chain smoking. Ha! Thus, P. went into the common vernacular as the most deadly substance in the world. Making a Plutonium bomb isn't that easy since you have to deal with the pure metal.
Although you should laugh at P. horror stories, it turns out that the world is awash in it (in the oxide form). Britain and France have been extracting P. for years from commercial used fuel. Their only hope was to fob it off to the Japanese in a form suitable for reactors. That story may have come to an end. Although the MOX reactor didn't do any worse than the others, the panic was much greater. Japan was drenched in P. when the North Koreans ignited their feeble atomic bomb, so all those stories of P. escaping were confused.
So, everybody thinks that Lead and Uranium are much safer than Plutonium, and I think that MOX is dead for now. Nothing like those Urban Myths!
Plutonium is easy to handle because the radiation it gives off is persistent but relatively weak. The type used in weapons, plutonium 239, has a half-life of 24,000 years and emits alpha rays. They make the plutonium feel warm to the touch but are so feeble that skin easily stops the radiation. If trapped inside the body, though, alpha rays can cause cancer.
Plutonium is the 'puppy dog' of radioactive materials. As with all alpha-emitters, just don't grind it up and have it as a smoothy! You would need to ingest a lot of it to really get up to the horror stories of the greenies. We old people could eat it for breakfast, and I don't know how long it would stay in the body if you were determined to get rid of it. I think the horror stories were derived from the urban myth that John Wayne inhaled a persistent speck of P. into his lungs, and this had an effect over that of chain smoking. Ha! Thus, P. went into the common vernacular as the most deadly substance in the world. Making a Plutonium bomb isn't that easy since you have to deal with the pure metal.
Although you should laugh at P. horror stories, it turns out that the world is awash in it (in the oxide form). Britain and France have been extracting P. for years from commercial used fuel. Their only hope was to fob it off to the Japanese in a form suitable for reactors. That story may have come to an end. Although the MOX reactor didn't do any worse than the others, the panic was much greater. Japan was drenched in P. when the North Koreans ignited their feeble atomic bomb, so all those stories of P. escaping were confused.
So, everybody thinks that Lead and Uranium are much safer than Plutonium, and I think that MOX is dead for now. Nothing like those Urban Myths!
Geology- Yo-Yo Subduction
Article
There are still many details of subduction that have yet to 'surface'. Most interesting is the question of how subduction can support a mountain range. These people have found some interesting complexities.
"This simple movement of a plate going down is much more complicated and has an internal chaotic movement," says Rubatto. "This is yo-yo subduction."
There are still many details of subduction that have yet to 'surface'. Most interesting is the question of how subduction can support a mountain range. These people have found some interesting complexities.
"This simple movement of a plate going down is much more complicated and has an internal chaotic movement," says Rubatto. "This is yo-yo subduction."
Saturday, April 9, 2011
OPG Distributes Panic Pamphlets
Article
They aren't quite throwing them out of airplanes, but it seems quite an effort. I'm glad they think that people would believe spokesmen. Do they have any experts on this? No, they got rid of them a long time ago. If the pamphlets don't work, what next?
Reminds me of the old tv show where they were throwing frozen turkeys out of a helicopter for a promotion. Did a fair bit of damage. :)
They aren't quite throwing them out of airplanes, but it seems quite an effort. I'm glad they think that people would believe spokesmen. Do they have any experts on this? No, they got rid of them a long time ago. If the pamphlets don't work, what next?
Reminds me of the old tv show where they were throwing frozen turkeys out of a helicopter for a promotion. Did a fair bit of damage. :)
Clean your dishwasher
So normally you think that the dishwasher should really take care of itself. I mean, it CLEANS!
But sadly, the dang thing needs cleaning out once in a while. So when I discovered that it wasn't fully draining (again) I went to take apart the main drain assembly under the sink. The last time it was clogging, I discovered that these things needed cleaning every 20 years or so. This is easy to do, by just unscrewing the thread, and sliding down the plastic off the sinks. If you put it in yourself and glued everything, well, you're in trouble.
So I took it apart and cleaned it. There was a table knife in the drain! So I really thought this was the problem, until I tested the dishwasher with the hose draining into a bucket, and the water only trickled out. Poops! I put in lots of chemicals.... Poops Again!
Then I found out you actually have to take apart the whole lower gungy thing! The internet was not clear on how to do this, but I found out that, for a newer GE model, you crawl in with a very powerful LED flashlight, and you see these tricky little plastic tabs under the rotating arm. This is the key to the whole thing! You barely nudge one with a flat screwdriver, and the arm just twists out counterclockwise.
Man, was that all really gross! Everything comes out easy after that, and you get access to the little sump hole. But I scooped everything out, and the drain still didn't work (I found that by turning off the water, and hitting Reset many times, all the water could be removed). Then, I went to the hot tub chemicals, and really put in something that sizzled! It worked!
But sadly, the dang thing needs cleaning out once in a while. So when I discovered that it wasn't fully draining (again) I went to take apart the main drain assembly under the sink. The last time it was clogging, I discovered that these things needed cleaning every 20 years or so. This is easy to do, by just unscrewing the thread, and sliding down the plastic off the sinks. If you put it in yourself and glued everything, well, you're in trouble.
So I took it apart and cleaned it. There was a table knife in the drain! So I really thought this was the problem, until I tested the dishwasher with the hose draining into a bucket, and the water only trickled out. Poops! I put in lots of chemicals.... Poops Again!
Then I found out you actually have to take apart the whole lower gungy thing! The internet was not clear on how to do this, but I found out that, for a newer GE model, you crawl in with a very powerful LED flashlight, and you see these tricky little plastic tabs under the rotating arm. This is the key to the whole thing! You barely nudge one with a flat screwdriver, and the arm just twists out counterclockwise.
Man, was that all really gross! Everything comes out easy after that, and you get access to the little sump hole. But I scooped everything out, and the drain still didn't work (I found that by turning off the water, and hitting Reset many times, all the water could be removed). Then, I went to the hot tub chemicals, and really put in something that sizzled! It worked!
Friday, April 8, 2011
Arkansa Earthquakes Picking Up Again
Very interesting that the injection has theoretically stopped, but the earthquakes are picking up again. Did they come to some secret agreement on their Mar 29 meeting? Are they injecting again?
For now I'll just assume some corruption here and they have restarted. If they haven't restarted, then it might be due to rainfall amounts, and the whole mechanism has been blown open. Expect the 4+'s soon!
Ontario Nuclear Review
Article
Another article on the nuclear issue. If they are ever going to do a review, what are they basing it on? Recorded seismicity? They don't need to spend extra billions on seismic design for the new plants, simple things will do.
Another article on the nuclear issue. If they are ever going to do a review, what are they basing it on? Recorded seismicity? They don't need to spend extra billions on seismic design for the new plants, simple things will do.
Thursday, April 7, 2011
Southern Ontario Seismic Network - 20 Years!
SOSN
This is a happy story about the Ontario nuclear industry. Without their money, all the seismicity of southern Ontario would have been shoved aside, in favour of the big boys on the west and east coasts. They even put in some borehole seismometers for the Bruce Thing, although nobody has heard since about them.
But I think it's getting a bit raggy now. I see they still are recording earthquakes, but nobody has been plotting maps since 2009! Are they being starved with this general apathy about earthquakes? I pray this isn't the case, since recording earthquakes is the bare minimum for new nuclear.
Anyway, I call it a 20 year anniversary, since it was 1991 when we finally settled in with the first group of decent seismometers. It was then that we discovered that the majority of earthquakes loved to be underwater. Why? The locations of historical earthquakes were all plotted along the shore, since that was where the people lived. That was our first major discovery.
Now, without nice maps, we can't look at the Hamilton fault with more detail. I think that makes most people in Ontario happy.....
This is a happy story about the Ontario nuclear industry. Without their money, all the seismicity of southern Ontario would have been shoved aside, in favour of the big boys on the west and east coasts. They even put in some borehole seismometers for the Bruce Thing, although nobody has heard since about them.
But I think it's getting a bit raggy now. I see they still are recording earthquakes, but nobody has been plotting maps since 2009! Are they being starved with this general apathy about earthquakes? I pray this isn't the case, since recording earthquakes is the bare minimum for new nuclear.
Anyway, I call it a 20 year anniversary, since it was 1991 when we finally settled in with the first group of decent seismometers. It was then that we discovered that the majority of earthquakes loved to be underwater. Why? The locations of historical earthquakes were all plotted along the shore, since that was where the people lived. That was our first major discovery.
Now, without nice maps, we can't look at the Hamilton fault with more detail. I think that makes most people in Ontario happy.....
Wednesday, April 6, 2011
Geology - Dilute Gold Deposits
Article
Yeah, nice, uncontroversial geology! 40 million years ago, Nevada was split by a big, hot spreading ridge that ended up under Yellowstone. It's all 'Basin and Range', which are all extension grabens. At this time, lots of deep stuff flowed to the surface, carrying gold. Why does gold live deep? Perhaps when the early Earth was partially molten it separated out and settled deep due to it's high density. Perhaps at 40 km we have a sold layer of pure gold!
In an interview, Cline and Simon explained how they brainstormed scenarios on the origin of invisible gold during a retreat two years ago with the report's other authors, UNLV's Anthony Longo and John Muntean of the Bureau of Mines and Geology.
"We spent three days and two nights. We ate and slept thinking about this and divided up the questions and sorted out the answers," Cline said.
Now, that's geology!
Yeah, nice, uncontroversial geology! 40 million years ago, Nevada was split by a big, hot spreading ridge that ended up under Yellowstone. It's all 'Basin and Range', which are all extension grabens. At this time, lots of deep stuff flowed to the surface, carrying gold. Why does gold live deep? Perhaps when the early Earth was partially molten it separated out and settled deep due to it's high density. Perhaps at 40 km we have a sold layer of pure gold!
In an interview, Cline and Simon explained how they brainstormed scenarios on the origin of invisible gold during a retreat two years ago with the report's other authors, UNLV's Anthony Longo and John Muntean of the Bureau of Mines and Geology.
"We spent three days and two nights. We ate and slept thinking about this and divided up the questions and sorted out the answers," Cline said.
Now, that's geology!
Tuesday, April 5, 2011
Old folks talk
Forget this blog! It just causes me grief going up against the stony Japanese faces of our nuclear industry. We now find what corruption this hid in Japan with all their falsified safety reports. Here, it's too much work to falsify anything, so it's just selective truth.
So, I'm arranging my talk at the old folks home. This modern facility has all the stuff for a slide show, but I like to get down to audience participation. I'll do my slinky's and I'll simulate fault rupture with people!
Still working on details.
So, I'm arranging my talk at the old folks home. This modern facility has all the stuff for a slide show, but I like to get down to audience participation. I'll do my slinky's and I'll simulate fault rupture with people!
Still working on details.
Monday, April 4, 2011
Japan Tsunami Hit 38 m - 125 ft.
Article
Wow! So a little seawall would have done nothing to this. Even if the nuclear plant had a 10 m seawall, the water would have just jumped it. I think you have to put the backup generators on top of rugged buildings.
But get this! This is not the record holder! There was a higher tsunami. Now that the M9 has shot its load, they should not worry about big tsunamis on that coast, but go to the other areas.
Wow! So a little seawall would have done nothing to this. Even if the nuclear plant had a 10 m seawall, the water would have just jumped it. I think you have to put the backup generators on top of rugged buildings.
But get this! This is not the record holder! There was a higher tsunami. Now that the M9 has shot its load, they should not worry about big tsunamis on that coast, but go to the other areas.
Rest of the world pushes nuclear transparency
Article
“The worries of millions of people throughout the world about whether nuclear energy is safe must be taken seriously,” International Atomic Energy Agency Director General Yukiya Amano said, according to a transcript of his speech. “Rigorous adherence to the most robust international safety standards and full transparency, in good times and bad, are vital for restoring and maintaining public confidence in nuclear power.”
The partial meltdown at Fukushima, where greater public scrutiny may have uncovered decades of falsified safety reports, has changed the way people view international nuclear incidents. Measurement networks showing how radiation plumes move globally, along with commercial satellite imagery and Internet communication, mean the public has more information than ever before about the consequences of nuclear breakdowns.
Not going to happen here! We've got internet download caps, so they treat us like idiots. :)
“The worries of millions of people throughout the world about whether nuclear energy is safe must be taken seriously,” International Atomic Energy Agency Director General Yukiya Amano said, according to a transcript of his speech. “Rigorous adherence to the most robust international safety standards and full transparency, in good times and bad, are vital for restoring and maintaining public confidence in nuclear power.”
The partial meltdown at Fukushima, where greater public scrutiny may have uncovered decades of falsified safety reports, has changed the way people view international nuclear incidents. Measurement networks showing how radiation plumes move globally, along with commercial satellite imagery and Internet communication, mean the public has more information than ever before about the consequences of nuclear breakdowns.
Not going to happen here! We've got internet download caps, so they treat us like idiots. :)
Sunday, April 3, 2011
Google and the social experiment
Now that they've cut off the Knol thing, I am wondering what Google will keep. I just did their new thing with www.haroldasmis.ca but I don't know what to do with it. It appears to be a tightly controlled web site by Yola, and you fix it up with their tools. I think Google does the storage, but I don't know what the limits are, and I don't know how this relates to Google Sites, since they are calling it the same thing.
But then I realized that Google has been a social network all along. They make their money serving up sleazy "Rent a Girl" ads, but how did their search algorithm actually work? It depended on the hard work of others who put up 'thoughtful' links. G depended on the whole universe of blogs, web sites, and Wikipedia. When I wrote an article, I carefully scanned everything and came up with a few good links, and G snatched those up. Now that everybody wants to play the system, they rely on this content creation more and more.
I've concluded they have a very heavy weight on my stuff, and will want to keep Blogger and Sites up, at least. When I could never see anything from my knols, I just put in a link, and poof! the next day it was at the top of a search.
G has a serious threat from 'walled gardens' such as Facebook. If those people do all the hard work of vetting links, who can G sponge off of? So, I think for a while, they will be putting billions into content creation that they can scan.
But then I realized that Google has been a social network all along. They make their money serving up sleazy "Rent a Girl" ads, but how did their search algorithm actually work? It depended on the hard work of others who put up 'thoughtful' links. G depended on the whole universe of blogs, web sites, and Wikipedia. When I wrote an article, I carefully scanned everything and came up with a few good links, and G snatched those up. Now that everybody wants to play the system, they rely on this content creation more and more.
I've concluded they have a very heavy weight on my stuff, and will want to keep Blogger and Sites up, at least. When I could never see anything from my knols, I just put in a link, and poof! the next day it was at the top of a search.
G has a serious threat from 'walled gardens' such as Facebook. If those people do all the hard work of vetting links, who can G sponge off of? So, I think for a while, they will be putting billions into content creation that they can scan.
Saturday, April 2, 2011
Big Knol Transfer
The following articles were transferred from my knol thing, which doesn't even show up on search engines any more. It is dead. I'm wondering about Google Sites, as well.
Megathrust Bedrock Geology of Ontario, Canada
New nuclear plants and nuclear waste sites should require a 'deeper' look at this area. As such, available data records, such as old oil company records have not been given adequate review.
There are two types of megathrusts in this world: a downward megathrust such as the big subduction zone near Vancouver, and an upward megathrust that is involved in mountain building.
Before 1.1 billion years ago, most of southern Ontario did not exist. It was a big deep ocean, with a bottom of cold oceanic crust. At that time, the cold oceanic crust began to sink, and the ocean started to converge, creating many subduction zones. Much like modern-day Japan, these subduction zones created volcanic island arcs, but still the ocean converged, and continents were starting to collide, much like Indian and Asia.
The first island arc complex collided with the cold core of North America (Archean). Huge megathrusts formed, creating a linear mountain range, as seen in the Rockies today. The heat and pressure, melded the rock together into a solid mass (metamorphism), and there was sufficient time before the next island arc collided, creating weak 'cold joints' between each episode.
These cold-joint megathrusts are clearly visible in deep seismic reflection data. The leading one is the Grenville Front (GF) fault, the middle one is the Central Metasedimentary (CM) fault, and the third is the Elzevir (EL) fault.
Note the perfect parallelism, as with most mountain ranges. Soon the oceanic convergence stopped, and the mountain ranges cooled down, eroded, and sunk. There may have been some backsliding collapse, which further weakened the main megathrusts. The basement rock was almost ground flat, but there remained very significant topography (Grand Canyon scale), at the megathrusts.
Eventually, the basement rock cooled so much that it went below sea level. Shallow seas made extensive deposits, as the basement deflated. The sediments made flat layers for the most part, except over the megathrusts, where they had some difficulty. The continued sedimentation solidified the rock, but the rock over the weak megathrusts continued to fracture and slide, forming faults.
At some point in the past, we Ontario residents were lucky that the deep Moho once again heated up, lifting Ontario into the position we now enjoy. This probably happened during the last mass convergence of the continents, just before the Atlantic separation. This uplift once again disturbed the megathrusts, and weakened the Paleozoic rock above.
Of course, we cannot forget the last few million years of ice sheets, and damage they did to the already fractured rock. The basement rock sunk under the ice load, and is still uplifting in parts, but the general trend is for the rock to be sinking again over the last 50 million years.
Now, each one of these megathrusts has the following generic cross-section:
This can be seen on the available seismic sections, except for the GF fault, which only barely appears on the Lake Erie lines.
The first map shows the maximum disturbance zones, which can be easily traced by long linears in shorelines, and rock topography. Along these lines lie most of our earthquake zones, oil and gas zones, and zones of smashed Palezoic rock. In between these lines are the the zones of solid rock, and high horizontal stresses.
These fault zones have severe implications on the seismic hazard of nuclear facilities located on them, as well as deep geological waste repositories. More effort should be undertaken to properly map these megathrusts, mainly by processing the available seismic data in Lake Huron.
There are two types of megathrusts in this world: a downward megathrust such as the big subduction zone near Vancouver, and an upward megathrust that is involved in mountain building.
Before 1.1 billion years ago, most of southern Ontario did not exist. It was a big deep ocean, with a bottom of cold oceanic crust. At that time, the cold oceanic crust began to sink, and the ocean started to converge, creating many subduction zones. Much like modern-day Japan, these subduction zones created volcanic island arcs, but still the ocean converged, and continents were starting to collide, much like Indian and Asia.
The first island arc complex collided with the cold core of North America (Archean). Huge megathrusts formed, creating a linear mountain range, as seen in the Rockies today. The heat and pressure, melded the rock together into a solid mass (metamorphism), and there was sufficient time before the next island arc collided, creating weak 'cold joints' between each episode.
These cold-joint megathrusts are clearly visible in deep seismic reflection data. The leading one is the Grenville Front (GF) fault, the middle one is the Central Metasedimentary (CM) fault, and the third is the Elzevir (EL) fault.
Note the perfect parallelism, as with most mountain ranges. Soon the oceanic convergence stopped, and the mountain ranges cooled down, eroded, and sunk. There may have been some backsliding collapse, which further weakened the main megathrusts. The basement rock was almost ground flat, but there remained very significant topography (Grand Canyon scale), at the megathrusts.Eventually, the basement rock cooled so much that it went below sea level. Shallow seas made extensive deposits, as the basement deflated. The sediments made flat layers for the most part, except over the megathrusts, where they had some difficulty. The continued sedimentation solidified the rock, but the rock over the weak megathrusts continued to fracture and slide, forming faults.
At some point in the past, we Ontario residents were lucky that the deep Moho once again heated up, lifting Ontario into the position we now enjoy. This probably happened during the last mass convergence of the continents, just before the Atlantic separation. This uplift once again disturbed the megathrusts, and weakened the Paleozoic rock above.
Of course, we cannot forget the last few million years of ice sheets, and damage they did to the already fractured rock. The basement rock sunk under the ice load, and is still uplifting in parts, but the general trend is for the rock to be sinking again over the last 50 million years.
Now, each one of these megathrusts has the following generic cross-section:
This can be seen on the available seismic sections, except for the GF fault, which only barely appears on the Lake Erie lines.The first map shows the maximum disturbance zones, which can be easily traced by long linears in shorelines, and rock topography. Along these lines lie most of our earthquake zones, oil and gas zones, and zones of smashed Palezoic rock. In between these lines are the the zones of solid rock, and high horizontal stresses.
These fault zones have severe implications on the seismic hazard of nuclear facilities located on them, as well as deep geological waste repositories. More effort should be undertaken to properly map these megathrusts, mainly by processing the available seismic data in Lake Huron.
Fault Geology of Hamilton, Ontario
Although the seismic hazard is about an order of magnitude less than the more active parts of the world, the seismic risk is not that far off, due to high population density, and a lack of 'earthquake living memory'.
Although we must always keep perspective, compared to very active zone, for Eastern North America (ENA) one significantly large fault whips down through Toronto and Hamilton. Now it happens in my many travels and fishing trips, that the most dramatic scenery is associated with earthquakes.
This fault appears to be most active at Hamilton, and the spectacular topography is a result.
The city of Hamiton is located at the west end of Lake Ontario. It is noted for its aromatic steel mills, and less noted for the swamps everywhere. In fact, I was told these swamps are extremely deep, and have blocked decent railroad access for years.
I have been playing around with Digital Elevation Models (DEM's), and viewers. I was using 3DEM to great success. Here a shaded relief view of Hamilton.
That great big gash in the Niagara Escarpment is the Dundas Valley, which was also a major glacial lake drainage outlet, and affects the sediments in Lake Ontario for a great distance. Nobody has really wondered why it is there.
The real fun with 3DEM is taking oblique views. Here's one, shooting down the fault.
The view would be much more spectacular if we could remove the soft sediments. Then you would see some scenery! Over the course of my career, we did a lot of geophysics out in the lake, where you can get an idea of the depths of the swamps.
Why do we even care about Hamilton? First off, the scenery is nice. Second, all those swamps are formed by an active fault, somewhat like sag ponds, but over a much longer time. They are doing a lot of house building in those ponds, and I think it is somewhat dangerous.
The next big earthquake in that area will be a high-speed thrust, much like some of the more destructive earthquakes that hit Japan recently. (I have dubbed them 'Fist of God' earthquakes!) The damage intensity will have a very narrow zone with a high Peak Ground Velocity (PGV). The deep swamps will amplify this ground motion 10 to 100 times. The damage will have unknown consequences. This earthquake will blow out the electricity and natural gas for most of Southern Ontario.
Yet, we merrily go on, ignoring this threat, not doing the slightest little thing to mitigate the disaster. Such is the power of living memory! We remember Hurricane Hazel, because it happened, yet this earthquake has the same general odds of happening. and has been ignored!
Although we must always keep perspective, compared to very active zone, for Eastern North America (ENA) one significantly large fault whips down through Toronto and Hamilton. Now it happens in my many travels and fishing trips, that the most dramatic scenery is associated with earthquakes.
This fault appears to be most active at Hamilton, and the spectacular topography is a result.
The city of Hamiton is located at the west end of Lake Ontario. It is noted for its aromatic steel mills, and less noted for the swamps everywhere. In fact, I was told these swamps are extremely deep, and have blocked decent railroad access for years.
I have been playing around with Digital Elevation Models (DEM's), and viewers. I was using 3DEM to great success. Here a shaded relief view of Hamilton.
That great big gash in the Niagara Escarpment is the Dundas Valley, which was also a major glacial lake drainage outlet, and affects the sediments in Lake Ontario for a great distance. Nobody has really wondered why it is there.
The real fun with 3DEM is taking oblique views. Here's one, shooting down the fault.
The view would be much more spectacular if we could remove the soft sediments. Then you would see some scenery! Over the course of my career, we did a lot of geophysics out in the lake, where you can get an idea of the depths of the swamps.
Why do we even care about Hamilton? First off, the scenery is nice. Second, all those swamps are formed by an active fault, somewhat like sag ponds, but over a much longer time. They are doing a lot of house building in those ponds, and I think it is somewhat dangerous.
The next big earthquake in that area will be a high-speed thrust, much like some of the more destructive earthquakes that hit Japan recently. (I have dubbed them 'Fist of God' earthquakes!) The damage intensity will have a very narrow zone with a high Peak Ground Velocity (PGV). The deep swamps will amplify this ground motion 10 to 100 times. The damage will have unknown consequences. This earthquake will blow out the electricity and natural gas for most of Southern Ontario.
Yet, we merrily go on, ignoring this threat, not doing the slightest little thing to mitigate the disaster. Such is the power of living memory! We remember Hurricane Hazel, because it happened, yet this earthquake has the same general odds of happening. and has been ignored!
Rock Mechanics
Tunnels and earthquakes have a special relationship.
In university, I went through UofT Engineering Science, and I specialized in Geophysics. It was more of a leftover choice, after I eliminated everything else! About the only thing you could do with this option was go into the oil exploration industry, so for my third year summer, I went to Calgary to work for an oil company.
I hated it! The only good thing was that I went into the mountains every weekend to look at the rocks. I love rocks! After that summer, the oil boom collapsed, and I had to look for another job anyway. I needed a career change, so I did my Masters degree in Rock Mechanics.
The most amazing thing about rocks, is that all rocks have a very similar friction angle. Their 'cohesion', however, varies from ultra-hard granite, to near-sand. Also, rocks are marvelously fractal, meaning that they behave mostly the same, from a very small scale to a very large scale.
My very first work, when I got out of university, was to look at underground structures - tunnels and caverns. It's a bit different to design infrastructure tunnels, than mining. In mining you can take slow, controlled failure, because you can re-excavate access tunnels. In fact, continuous movement is the norm in mines, simply because you are excavating all around and changing the stress fields.
I was looking at the dynamic stability of these tunnels and caverns, particularly for nuclear plants and waste repositories. The waste repository has the difficult problem of excess heat from the fuel bundles, thus it is always heating up, thus the stresses are always changing. On the other hand, a nuclear plant water intake tunnel is quite the simple thing; it should stand up long enough to slap in a thick concrete lining. Nothing much 'dynamic' about these tunnels!
Besides standing up to heat, there is the added problem of low-probability and time-distant events for a nuclear waste repository. Actually anything is better than having the waste hang around in concrete cans, but the 'people' demand 'million year' time frames, simply because someone (in the distant future) could theoretically dig into an ultra-deep repository and start eating the nuclear fuel.
As you see, there is little rationality in the nuclear waste biz, but it leads to fun things such as determining what happens during the next ice age. (No matter that those cans on the surface all get ground up and spat out!).
Rock mechanics has been mostly concerned with rock failure under the following-load of gravity. If your tunnel doesn't fall down on your head, you're happy! What I was studying 30 years ago, was the impact of earthquakes on caverns and tunnels.
Underground workings have generally done very well with seismic shaking. They do not resonate, and thus, are not very amenable to conventional seismic analysis, which I think sucks, anyway! For underground structures, I had to go into a totally different type of analysis, which is just now being applied to buildings, thanks to cheap computing!
Probably the best way to look at the seismic performance of underground things, is to use the methodology of 'Experience Data', which I used extensively for nuclear plants. Around the world, there have been many tunnels and mines exposed to strong ground motion. The performance has varied from very good, to very bad. "It never rains, but it pours!". If a tunnel fails during an earthquake, it can flood within seconds!
I went into the analysis of what actually happens to a tunnel during an earthquake. The earthquake source radiates seismic waves, which is easy to model with a wave propagation program. What I discovered 30 years ago, was the variation of peak seismic stress with distance. Although there is virtually no limit to peak stress in the near-field, seismic waves that propagate a decent distance, cannot be non-linear. In other words, the peak stress disturbance must go down to the level where it does not interact with the rock! This is extremely important, and saves us a lot during earthquakes.
Nobody had actually measured the peak stresses of a passing seismic wave, so I needed to go for another measurement. I did some computer modeling, and some research, and came to the conclusion that Peak Ground Velocity (PGV) offered a good correlation with peak stress. The only problem was, at the time, nobody gave a damn about PGV.
30 years ago, the seismic world was totally dominated by California. Strong ground motions, correlation with damage, etc, was all from the deep soil basins. The whole concept of Standard Response Spectrum and modal seismic analysis was due to the fact that basin motions were low-frequency, long rumbling things. In this world, the measurement of Peak Ground Acceleration (PGA), expressed as a percentage of g, was all the rage.
I knew there was something wrong here. We had sent a crew, measuring stresses at the recent Miramichi earthquake, and had found something unusual. The crews reported that the ground was crackling with small earthquakes after the main event. Some would really thump the drill rig! I knew that if you had measured the PGA, you would get around 1g, but clearly these things had no energy to damage. I was convinced that PGA was a useless measure for the rest of the world!
When I went back to computer modeling, I found there was no physical limit to PGA, since you could just increase the frequency, and PGA would go through the roof! It was only in California, where the frequencies were forced to be low, that it was valid.
Thus, began my great campaign to wipe PGA off the seismic map! After 30 years, there is now some glimmer of hope! But I digress, as usual. My next step was to see if there was some limit to PGV on rock, and thus a limit on peak stress. As well, I had to determine if there was some indication of how much peak stress was required to damage a tunnel or cavern.
At the time, 30 years ago, PGV was never recorded, let alone discussed. So I made a study of the Modified Mercalli Index, which had recently been tied to PGV, and was the best surrogate. The PGV approximately doubled for every jump in the MMI, and I began to collect stories about the several point difference between rock and soil.
Thus began my classic report Seismic Ground Motion on Rock and Soil (which I loved!). In that report, I looked very hard for situations where there were both rock and soil reports of ground shaking. It was difficult, since nobody ever reported where there wasn't any damage!
I was lucky to find this absolutely inspirational book in the old library at Hydro (since kaput!): Freeman,J.R., 1932. Earthquake Damage and Earthquake Insurance. He was a total rationalist, and looked at actually earthquake damage and non-damage. (I should have stolen that damn book!).
He noted that there was no damage on Telegraph Hill (solid rock), and buildings designed with a flat 10% lateral load did quite well. The difference in intensity between the hill, and the landfill harbour was about 5 points! Later, I had the opportunity to walk the Hill, and view the harbour, but I digress.
I had lots of stories, for example the 1944 Cornwall earthquake. On the Leda clay, people couldn't stand up, and there was extensive damage. But according to my old grandfather-in-law, there was nothing on the highlands (hard till). The 1925 St. Lawrence earthquake devastated the river lowlands, but didn't wake the guests at the Chateau, nor plink off any icicles!
After this, I concluded that PGV was exceedingly low on solid ground (rock or hard till), and soft sludge could amplify by a factor of 10 to 100 times!
I, therefore, went with a max of about 5 cm/s on rock for Eastern North America (ENA), and set about to check the stress levels for this PGV. As well, I had to determine the 'sensitivity' of the rock to stress changes.
Having determined that there were generally low PGV's for solid rock, I was prepared to slide to home plate, by going back to Rock Mechanics! This subject is mostly about the behaviour of cracked, wet rock, which is exactly what have in earthquakes.
I was running a finite-differences wave propagation computer code, which I had written myself. In it, I could view traveling seismic waves, look at the generated stresses, and bounce waves off tunnels! All in all, better than Nintendo! Best of all, I could make the rock properties non-linear, and I found that if I introduced the tiniest non-linearity, the wave propagation would fail.
What's the source of true non-linearity in rock? It's when the stress disturbance of the wave causes some energy absorption in the rock. This can come from water flow in and out of pores, or sliding along a fracture. I was most interested in what could induce rock to slide.
That was fairly easy to look at, since you can't really disturb rock without making a ton of micro-seismic noise, and the South African gold mines had been wired up for sound, a long time ago. They had the great ability to actually generate earthquakes, and you could see the effect by mining through it afterward! In general, I found that the micro-crack damage zone was very confined to the actually slipped fault, and the seismic waves only induced rock failure, at a distance, if things were extremely unstable.
My next step was to estimate how close my target rock (Eastern North America, ENA) was to failure. This would also help determine the maximum induced stress, for if you knew what could cause micro-slippage, you would have another confirmation, along with the low PGV. For that, I ventured into Grand Geology, and Induced Seismicity!
I was working on the sub-theory that propagating seismic waves could only carry a little bit of stress, due to the general weakness of the rock. For that to hold, the basement of ENA would have to be at its Limit State, which means it is as close to failure as you can get, and still be relatively stable.
At the time there was a lot of evidence in favour, and subsequent papers continue to support this. Essentially, we have an ancient craton, that has been pushed and pulled to a great extent over the last billion years. It would get greatly pushed (compressed) in between expansion cycles, when it was over cold mantle. It would be pulled (tension) when the heat built up underneath, and the continents were splitting up again.
Currently, we are in a big cold trough, and the craton has settled in. This puts it a generally high compressive state. You can see that whenever the water head is increased by about 10 m (induced earthquakes), you get earthquakes, or when a large extent of rock is removed (as in quarrying), of about 3 m.
Into this mix came glaciation, which had a tremendous effect on the rock. Although a uniform ice load would merely act as a big wet blanket, the ice loading is far from uniform. During surges, and retreats, it builds up a very high shear stress, combined with high water pressures being injected into the rock. I don't think that anyone has appreciated this, except moi!
Although the glaciation relieved some stress, it also shattered the rock, through hydrofracturing (which is the splitting of rock through injected fluid pressure). My prediction from this, was that we would see extensively fractured rock down to about 1 km, at relatively low stress, then we would see unfractured rock at very high compressive stress. In other words, the measured stress increased with the rock's ability to hold it.
I was lucky to have this sub-theory tested with the construction of the mostly useless URL (Underground Research Laboratory), which was a great "FEED ME!" AECL gift. This mine went about 1 km down, where they encountered great big 'sub-horizontal' features, which were essentially underground rivers hooked to the surface. Seeing that this was probably not a good thing (except for Bruce!), they proceeded to go under these rivers.
What they encountered was extremely high stresses. So much so that the rock virtually exploded when touched! We really couldn't put used fuel here because of all the heat produced, and the rock would be shattered within a decade! Thus, URL ended both with a bang, and a whimper!
So, in the end I had good justification that the maximum stress from a seismic wave was only about an atmosphere, and the PGV was limited to about 5 cm/sec. This was scarcely enough to spill a coffee in a mine, and shows how even large earthquakes mostly do nothing to mines. Still, I was determined to model it in a computer, because that was fun!
I've always tended to approach analysis slightly differently than most people at the old company. They always wanted to go for the 'Big One' that proved a political point, such as 'the reactor is safe'. I always called that 'Snow, by analysis'. I used analysis to improve the fundamental science, since I knew what uncertainties were (as opposed to them!), and I wanted to see the effects of 'what if's'.
I love working with wave propagation model (no, not that kind!) This is the most fun a dynamics person can have cheaply! My first work was with code I had written myself, and then I eventually went to commercial code. But for that, you needed powerful Linux computers, and not the namby-pamby Windows crap that bureaucracies like to buy! Needless to say, in modern times, I overran the computing power I had, and became bored. Still, I learned something.
With my simple wave modeling, I showed that the tunnel was a small fraction of the seismic wavelength, and did no 'funny stuff'. To show funny stuff, I propagated into beds of soft soil, and saw tremendous amplifications!
I concluded, that under normal, well-designed conditions, a tunnel had nothing to fear from earthquakes, and this has been proven out in the field. But what of poorly designed underground structures? They had a serious problem...
Thus I created (just now!), Harold list of tunneling bo-bo's:
-Don't rely on grout! Any water channels get reactivated by seismic motions. The tiniest amount of differential movement can shatter grout. Many tunnels have been instantly flooded after an earthquake.
-Don't have open zones, or major fractures near your cavern. Earthquakes can suddenly change the regional groundwater flow. Seismic ground motion from very far away can dramatically affect well levels, and even blast natural gas into the air.
-Build in a lot of margin. The stress impact of an earthquake is less than the stress changes you would expect over the life of the cavern. It has to be designed so that there is no chance of spontaneous failure, or rockbursts.
In university, I went through UofT Engineering Science, and I specialized in Geophysics. It was more of a leftover choice, after I eliminated everything else! About the only thing you could do with this option was go into the oil exploration industry, so for my third year summer, I went to Calgary to work for an oil company.
I hated it! The only good thing was that I went into the mountains every weekend to look at the rocks. I love rocks! After that summer, the oil boom collapsed, and I had to look for another job anyway. I needed a career change, so I did my Masters degree in Rock Mechanics.
The most amazing thing about rocks, is that all rocks have a very similar friction angle. Their 'cohesion', however, varies from ultra-hard granite, to near-sand. Also, rocks are marvelously fractal, meaning that they behave mostly the same, from a very small scale to a very large scale.
My very first work, when I got out of university, was to look at underground structures - tunnels and caverns. It's a bit different to design infrastructure tunnels, than mining. In mining you can take slow, controlled failure, because you can re-excavate access tunnels. In fact, continuous movement is the norm in mines, simply because you are excavating all around and changing the stress fields.
I was looking at the dynamic stability of these tunnels and caverns, particularly for nuclear plants and waste repositories. The waste repository has the difficult problem of excess heat from the fuel bundles, thus it is always heating up, thus the stresses are always changing. On the other hand, a nuclear plant water intake tunnel is quite the simple thing; it should stand up long enough to slap in a thick concrete lining. Nothing much 'dynamic' about these tunnels!
Besides standing up to heat, there is the added problem of low-probability and time-distant events for a nuclear waste repository. Actually anything is better than having the waste hang around in concrete cans, but the 'people' demand 'million year' time frames, simply because someone (in the distant future) could theoretically dig into an ultra-deep repository and start eating the nuclear fuel.
As you see, there is little rationality in the nuclear waste biz, but it leads to fun things such as determining what happens during the next ice age. (No matter that those cans on the surface all get ground up and spat out!).
Rock mechanics has been mostly concerned with rock failure under the following-load of gravity. If your tunnel doesn't fall down on your head, you're happy! What I was studying 30 years ago, was the impact of earthquakes on caverns and tunnels.
Underground workings have generally done very well with seismic shaking. They do not resonate, and thus, are not very amenable to conventional seismic analysis, which I think sucks, anyway! For underground structures, I had to go into a totally different type of analysis, which is just now being applied to buildings, thanks to cheap computing!
Probably the best way to look at the seismic performance of underground things, is to use the methodology of 'Experience Data', which I used extensively for nuclear plants. Around the world, there have been many tunnels and mines exposed to strong ground motion. The performance has varied from very good, to very bad. "It never rains, but it pours!". If a tunnel fails during an earthquake, it can flood within seconds!
I went into the analysis of what actually happens to a tunnel during an earthquake. The earthquake source radiates seismic waves, which is easy to model with a wave propagation program. What I discovered 30 years ago, was the variation of peak seismic stress with distance. Although there is virtually no limit to peak stress in the near-field, seismic waves that propagate a decent distance, cannot be non-linear. In other words, the peak stress disturbance must go down to the level where it does not interact with the rock! This is extremely important, and saves us a lot during earthquakes.
Nobody had actually measured the peak stresses of a passing seismic wave, so I needed to go for another measurement. I did some computer modeling, and some research, and came to the conclusion that Peak Ground Velocity (PGV) offered a good correlation with peak stress. The only problem was, at the time, nobody gave a damn about PGV.
30 years ago, the seismic world was totally dominated by California. Strong ground motions, correlation with damage, etc, was all from the deep soil basins. The whole concept of Standard Response Spectrum and modal seismic analysis was due to the fact that basin motions were low-frequency, long rumbling things. In this world, the measurement of Peak Ground Acceleration (PGA), expressed as a percentage of g, was all the rage.
I knew there was something wrong here. We had sent a crew, measuring stresses at the recent Miramichi earthquake, and had found something unusual. The crews reported that the ground was crackling with small earthquakes after the main event. Some would really thump the drill rig! I knew that if you had measured the PGA, you would get around 1g, but clearly these things had no energy to damage. I was convinced that PGA was a useless measure for the rest of the world!
When I went back to computer modeling, I found there was no physical limit to PGA, since you could just increase the frequency, and PGA would go through the roof! It was only in California, where the frequencies were forced to be low, that it was valid.
Thus, began my great campaign to wipe PGA off the seismic map! After 30 years, there is now some glimmer of hope! But I digress, as usual. My next step was to see if there was some limit to PGV on rock, and thus a limit on peak stress. As well, I had to determine if there was some indication of how much peak stress was required to damage a tunnel or cavern.
At the time, 30 years ago, PGV was never recorded, let alone discussed. So I made a study of the Modified Mercalli Index, which had recently been tied to PGV, and was the best surrogate. The PGV approximately doubled for every jump in the MMI, and I began to collect stories about the several point difference between rock and soil.
Thus began my classic report Seismic Ground Motion on Rock and Soil (which I loved!). In that report, I looked very hard for situations where there were both rock and soil reports of ground shaking. It was difficult, since nobody ever reported where there wasn't any damage!
I was lucky to find this absolutely inspirational book in the old library at Hydro (since kaput!): Freeman,J.R., 1932. Earthquake Damage and Earthquake Insurance. He was a total rationalist, and looked at actually earthquake damage and non-damage. (I should have stolen that damn book!).
He noted that there was no damage on Telegraph Hill (solid rock), and buildings designed with a flat 10% lateral load did quite well. The difference in intensity between the hill, and the landfill harbour was about 5 points! Later, I had the opportunity to walk the Hill, and view the harbour, but I digress.
I had lots of stories, for example the 1944 Cornwall earthquake. On the Leda clay, people couldn't stand up, and there was extensive damage. But according to my old grandfather-in-law, there was nothing on the highlands (hard till). The 1925 St. Lawrence earthquake devastated the river lowlands, but didn't wake the guests at the Chateau, nor plink off any icicles!
After this, I concluded that PGV was exceedingly low on solid ground (rock or hard till), and soft sludge could amplify by a factor of 10 to 100 times!
I, therefore, went with a max of about 5 cm/s on rock for Eastern North America (ENA), and set about to check the stress levels for this PGV. As well, I had to determine the 'sensitivity' of the rock to stress changes.
Having determined that there were generally low PGV's for solid rock, I was prepared to slide to home plate, by going back to Rock Mechanics! This subject is mostly about the behaviour of cracked, wet rock, which is exactly what have in earthquakes.
I was running a finite-differences wave propagation computer code, which I had written myself. In it, I could view traveling seismic waves, look at the generated stresses, and bounce waves off tunnels! All in all, better than Nintendo! Best of all, I could make the rock properties non-linear, and I found that if I introduced the tiniest non-linearity, the wave propagation would fail.
What's the source of true non-linearity in rock? It's when the stress disturbance of the wave causes some energy absorption in the rock. This can come from water flow in and out of pores, or sliding along a fracture. I was most interested in what could induce rock to slide.
That was fairly easy to look at, since you can't really disturb rock without making a ton of micro-seismic noise, and the South African gold mines had been wired up for sound, a long time ago. They had the great ability to actually generate earthquakes, and you could see the effect by mining through it afterward! In general, I found that the micro-crack damage zone was very confined to the actually slipped fault, and the seismic waves only induced rock failure, at a distance, if things were extremely unstable.
My next step was to estimate how close my target rock (Eastern North America, ENA) was to failure. This would also help determine the maximum induced stress, for if you knew what could cause micro-slippage, you would have another confirmation, along with the low PGV. For that, I ventured into Grand Geology, and Induced Seismicity!
I was working on the sub-theory that propagating seismic waves could only carry a little bit of stress, due to the general weakness of the rock. For that to hold, the basement of ENA would have to be at its Limit State, which means it is as close to failure as you can get, and still be relatively stable.
At the time there was a lot of evidence in favour, and subsequent papers continue to support this. Essentially, we have an ancient craton, that has been pushed and pulled to a great extent over the last billion years. It would get greatly pushed (compressed) in between expansion cycles, when it was over cold mantle. It would be pulled (tension) when the heat built up underneath, and the continents were splitting up again.
Currently, we are in a big cold trough, and the craton has settled in. This puts it a generally high compressive state. You can see that whenever the water head is increased by about 10 m (induced earthquakes), you get earthquakes, or when a large extent of rock is removed (as in quarrying), of about 3 m.
Into this mix came glaciation, which had a tremendous effect on the rock. Although a uniform ice load would merely act as a big wet blanket, the ice loading is far from uniform. During surges, and retreats, it builds up a very high shear stress, combined with high water pressures being injected into the rock. I don't think that anyone has appreciated this, except moi!
Although the glaciation relieved some stress, it also shattered the rock, through hydrofracturing (which is the splitting of rock through injected fluid pressure). My prediction from this, was that we would see extensively fractured rock down to about 1 km, at relatively low stress, then we would see unfractured rock at very high compressive stress. In other words, the measured stress increased with the rock's ability to hold it.
I was lucky to have this sub-theory tested with the construction of the mostly useless URL (Underground Research Laboratory), which was a great "FEED ME!" AECL gift. This mine went about 1 km down, where they encountered great big 'sub-horizontal' features, which were essentially underground rivers hooked to the surface. Seeing that this was probably not a good thing (except for Bruce!), they proceeded to go under these rivers.
What they encountered was extremely high stresses. So much so that the rock virtually exploded when touched! We really couldn't put used fuel here because of all the heat produced, and the rock would be shattered within a decade! Thus, URL ended both with a bang, and a whimper!
So, in the end I had good justification that the maximum stress from a seismic wave was only about an atmosphere, and the PGV was limited to about 5 cm/sec. This was scarcely enough to spill a coffee in a mine, and shows how even large earthquakes mostly do nothing to mines. Still, I was determined to model it in a computer, because that was fun!
I've always tended to approach analysis slightly differently than most people at the old company. They always wanted to go for the 'Big One' that proved a political point, such as 'the reactor is safe'. I always called that 'Snow, by analysis'. I used analysis to improve the fundamental science, since I knew what uncertainties were (as opposed to them!), and I wanted to see the effects of 'what if's'.
I love working with wave propagation model (no, not that kind!) This is the most fun a dynamics person can have cheaply! My first work was with code I had written myself, and then I eventually went to commercial code. But for that, you needed powerful Linux computers, and not the namby-pamby Windows crap that bureaucracies like to buy! Needless to say, in modern times, I overran the computing power I had, and became bored. Still, I learned something.
With my simple wave modeling, I showed that the tunnel was a small fraction of the seismic wavelength, and did no 'funny stuff'. To show funny stuff, I propagated into beds of soft soil, and saw tremendous amplifications!
I concluded, that under normal, well-designed conditions, a tunnel had nothing to fear from earthquakes, and this has been proven out in the field. But what of poorly designed underground structures? They had a serious problem...
Thus I created (just now!), Harold list of tunneling bo-bo's:
-Don't rely on grout! Any water channels get reactivated by seismic motions. The tiniest amount of differential movement can shatter grout. Many tunnels have been instantly flooded after an earthquake.
-Don't have open zones, or major fractures near your cavern. Earthquakes can suddenly change the regional groundwater flow. Seismic ground motion from very far away can dramatically affect well levels, and even blast natural gas into the air.
-Build in a lot of margin. The stress impact of an earthquake is less than the stress changes you would expect over the life of the cavern. It has to be designed so that there is no chance of spontaneous failure, or rockbursts.
Fault Rupture Boring Story
A mixture of original research, hard facts, humour, and general stubbornness against the 'established' pay wall.
This was on my blog as one of my many 'boring stories', which I have pieced together for prosperity. I thought up these when I had numerous cousins at the cottage, and I wanted to put them to sleep.
It's fun on the dock, fishing. All my intellectual energy is totally drained from me, especially if I'm cut off from civilization for a long time. I'm back for a couple of days, and thought it's time for another boring story. This one is about fault mechanics, which I think is the most misunderstood subject of all time (it helps to have a rock mechanics background!).
The whole reason we have earthquakes is because of a simple little physical phenomenon that we observe when we have a shower in a cheap hotel, while forgetting to put in the rubber bathmat.
One minute our feet are firmly on the tub, stuck like glue. The next second, we do one little thing, and swoosh! If we are lucky, the clingy plastic shower curtain has saved us.
This is the most dramatic demonstration that I know, showing the difference between static and dynamic friction. I've done some more details in Fault Friction.
Wet, fractured rock behaves almost the same throughout the world, and this is the stuff of earthquakes! Without a difference, in wet rock, between static and dynamic friction, we would be without most earthquakes (those extremely deep earthquakes are a bizarre exception, but who cares about them?)
So all earthquakes start with a single crystal (grain) of rock (mineral), rubbing against another. There is shear stress, which is a force trying to slide the grains past each other, and there is the normal stress, which is the force jamming them together. At the very tiny point of contact, the minerals (quartz, most likely), are cold-welded, making a very strong adhesion bond.
The shear stress attempts to break these bonds, by inducing tiny molecular earthquakes. Studies show that if we bake these things so that there is no water, then new bonds are formed as quickly as old ones are broken. Thus, the resistance to slipping remains a constant value.
Thus, good old water is need for some action! If we sprinkle in some water, then two very interesting things happen. Firstly, we do not have stability at the near-failure point, because the water acts to eat away at the adhesion points. This little thing, called stress corrosion, is one of the best, totally unappreciated discoveries from the giant money-sucking pit, called the AECL Underground Research Laboratory (URL) (RIP). (Thanktheloard for massive gov't pork!)
Secondly, once the adhesion bonds start to break, they are covered in little water molecules, just like the other potential contact points. When a new adhesion contact wants to form, there's that nasty water gunking things up!
So now it takes some time to form some new bonds, time that the slippery feet (or mineral grains) don't have if there is a big following force (like gravity, or the San Andreas!). The sliding surface starts to zoom, and we have dynamic friction.
As you fall asleep, you may wonder what bathtub feet, and mineral grains have to do with a big old fault. The answer lies in self-similarity and Power Law. Much like a ratty old US bridge, everything can be represented as tiny little feet slipping, over and over again, combining into larger and larger feet, until the whole shebang blows!
Earthquakes remain boring to us, who live in a fool's paradise. Those, who have recently been whacked, have other worries.
We saw how the crystal grains are little feet on the bathtub, but how does this work up to Peruvian scale? Think of a giant pile of sand, housed in one of those roadside giant boob-huts (is this just an Ontario inside joke?). You are hanging on the rafters, watching a stream of sand fall on the pile. As you watch, you see a pattern of little slides and shifts, and sometimes a bigger slide. The sand is at its angle of repose.
Now, you lower yourself upside down, using your spidey web, with the sand stream reducing as you get closer. As you focus your spidey-vision on the sand, you still see the same pattern of many little slides, and larger ones. In fact, by just looking at the pattern, you can't tell how far away you are, from the sand.
You get closer and closer to the sand. At this time, you switch on the incredible shrinking ray, so you get tinier. Still, the pattern remains the same. Finally, when the sand grains start to look like giant boulders, the pattern breaks, but each boulder is following some simple laws of physics.
In fact, we like to model little blocks because it's fun! And it has some lessons for us, mainly that a tiny movement in one place can trigger a larger movement quite far away.
But back to the pile of sand. We see that the pattern of sand failures is self-similar on all scales, but with a big BUT! That is, the self-similarity only holds between two size scales: that of the whole sand pile, and the size of the individual sand grain.
The concept of two limiting scales really screws up a lot of earthquake people, but I suppose they'll figure it out one day. :) We aren't too sure what the largest scale is (somewhere around a few thousand km), but we do know it varies for each earthquake mechanism. What I find amazing is how small the scale can get. We find that rock bursts in mines behave almost exactly the same as earthquakes, and that rock in a testing machine also shows classical earthquake behaviour to the grain scale. So, I'm fairly confident to state that power law (self similarity) holds from the micro to the mega earthquakes.
So if the entire side of Peru is one big foot in the bathtub, it is composed of smaller feet, which are in turn compose of even smaller feet, down to the tiniest grain. At various times, each foot slips on the bathtub. If you are carefully monitoring the feet with seismometers, you see lots of little slips setting up for a bigger foot. In fact, very roughly, you need about 10 little feet to completely slip, for a foot ten times bigger, and about 30 time more energy when it slips.
After millions of slips, the biggest one decides to go. It is your biggest foot that does most of the damage, and uplifts the mountains. Those little guys are just a necessary side-show. Is the M8 earthquake in Peru the biggest foot? Most likely not, since that area is know for M9's.
In Ontario, what is our biggest foot? It's probably the dimension of the Hamilton Fault zone, which might be around M6.5. When will that foot drop?
If you recall, I left you asleep at the point of wonder why we have earthquakes at all in Eastern North America (ENA). Really, if the continent is one big massive piece of tombstone granite, then any stress-relieving earthquake should just carve a 'stress-hole' like drilling a mine.
Once this giant Tim Hortons donut gets formed, the remaining rock arches around it, and leaves a perfectly stable structure, with an extinct fault in the middle. This doesn't happen on the plate margins, with all those plates sliding past each other, like those sliding number puzzles we had as kids. For the equivalent, we would need mountain ranges or visible fault sliding to keep the similar ENA earthquake hotspots going for a few million years.
Take a typical fault zone trying to grow up in ENA. It starts with a fractured weak spot, perhaps reactivated by the modern stress field. Eventually (perhaps), the shear stress builds up along a fracture, and the bath-tub feet let go! The fractured rock behaves exactly the same as in California or Peru.
But that's it! Our poor little earthquake has shot its load. The feet have lost their stress, and the surrounding rock has clamped up on our poor little fellow. He can't grow up...
That is, if our earthquake follows conventional thinking for ENA earthquakes. But no, our earthquake fault zone is smarter than that, it is following Harold's original thinking, which doesn't get into the university cartel, because they all got tenure!
Once our earthquake has caused its bump (like a Utah coalmine!), it looks around and sees what it has done, which is to freshly fracture a lot more rock. Its seismic effort hasn't gone into mountain building, or plate sliding, it's gone into fracture surface energy! The academics never thought of that!
But this isn't enough for Quakey (like that name?), in its battle against the implacable rock. Luckily, he's (she's?) under a big hunk of water, and water slowly flows into the new fractures. Now things are cooking! The water does all sorts of wonderful things. First, the water pressure reduces the normal stress on the faults and makes them more likely to slide again. Second, the water hydrofractures and extends existing tension cracks. Finally, the fresh water is corrosive and starts chewing at the adhesion points.
Quakey has become a growing entity, like the Blob that ate New York. So, under Hamilton, New Madrid, countless other ENA locations, we have growing things, which although not actually alive, can give a darn good account of themselves!
As Quakey grows, he can tap into more stress from the surrounding rock, just like we were excavating a new Utah coal mine (or an underground nuclear waste thingie!). He gives many signs of his growth, lots of little earthquakes, just like his bigger plate margin brothers. All the bathtub feet are working, and eventually there is a large, scale-limited earthquake. The process begins again for a bigger earthquake!
Quakey may start as a simple thrust fault along a pre-existing fracture, but soon suffers growing pains. The old fracture provides the water, but a simple thrust fault isn't enough to suck out all the stress from the surround rock. In order to avoid another stress lockup, he must start developing shear wings, which produce strike-slip earthquakes. When he eventually grows into a monster, he resembles the New Madrid fault system.
All the time, these zones are sending the signals to prove Harold is right, and the others are wrong, but the scientists and politicians are too cheap to provide the detailed seismic monitoring that is required. Only the Southern Ontario Seismic Network probably has sufficient horsepower and density, but the Hamilton zone is just a baby!
Everyday, these zones try to show themselves. They send typical 'fluid injection' earthquakes, they mix thrust and strike-slip mechanisms, and they only show up under bodies of water. But without monitoring, the world goes on arguing with Harold. :)
This was on my blog as one of my many 'boring stories', which I have pieced together for prosperity. I thought up these when I had numerous cousins at the cottage, and I wanted to put them to sleep.
It's fun on the dock, fishing. All my intellectual energy is totally drained from me, especially if I'm cut off from civilization for a long time. I'm back for a couple of days, and thought it's time for another boring story. This one is about fault mechanics, which I think is the most misunderstood subject of all time (it helps to have a rock mechanics background!).
The whole reason we have earthquakes is because of a simple little physical phenomenon that we observe when we have a shower in a cheap hotel, while forgetting to put in the rubber bathmat.
One minute our feet are firmly on the tub, stuck like glue. The next second, we do one little thing, and swoosh! If we are lucky, the clingy plastic shower curtain has saved us.
This is the most dramatic demonstration that I know, showing the difference between static and dynamic friction. I've done some more details in Fault Friction.
Wet, fractured rock behaves almost the same throughout the world, and this is the stuff of earthquakes! Without a difference, in wet rock, between static and dynamic friction, we would be without most earthquakes (those extremely deep earthquakes are a bizarre exception, but who cares about them?)
So all earthquakes start with a single crystal (grain) of rock (mineral), rubbing against another. There is shear stress, which is a force trying to slide the grains past each other, and there is the normal stress, which is the force jamming them together. At the very tiny point of contact, the minerals (quartz, most likely), are cold-welded, making a very strong adhesion bond.
The shear stress attempts to break these bonds, by inducing tiny molecular earthquakes. Studies show that if we bake these things so that there is no water, then new bonds are formed as quickly as old ones are broken. Thus, the resistance to slipping remains a constant value.
Thus, good old water is need for some action! If we sprinkle in some water, then two very interesting things happen. Firstly, we do not have stability at the near-failure point, because the water acts to eat away at the adhesion points. This little thing, called stress corrosion, is one of the best, totally unappreciated discoveries from the giant money-sucking pit, called the AECL Underground Research Laboratory (URL) (RIP). (Thanktheloard for massive gov't pork!)
Secondly, once the adhesion bonds start to break, they are covered in little water molecules, just like the other potential contact points. When a new adhesion contact wants to form, there's that nasty water gunking things up!
So now it takes some time to form some new bonds, time that the slippery feet (or mineral grains) don't have if there is a big following force (like gravity, or the San Andreas!). The sliding surface starts to zoom, and we have dynamic friction.
As you fall asleep, you may wonder what bathtub feet, and mineral grains have to do with a big old fault. The answer lies in self-similarity and Power Law. Much like a ratty old US bridge, everything can be represented as tiny little feet slipping, over and over again, combining into larger and larger feet, until the whole shebang blows!
Earthquakes remain boring to us, who live in a fool's paradise. Those, who have recently been whacked, have other worries.
We saw how the crystal grains are little feet on the bathtub, but how does this work up to Peruvian scale? Think of a giant pile of sand, housed in one of those roadside giant boob-huts (is this just an Ontario inside joke?). You are hanging on the rafters, watching a stream of sand fall on the pile. As you watch, you see a pattern of little slides and shifts, and sometimes a bigger slide. The sand is at its angle of repose.
Now, you lower yourself upside down, using your spidey web, with the sand stream reducing as you get closer. As you focus your spidey-vision on the sand, you still see the same pattern of many little slides, and larger ones. In fact, by just looking at the pattern, you can't tell how far away you are, from the sand.
You get closer and closer to the sand. At this time, you switch on the incredible shrinking ray, so you get tinier. Still, the pattern remains the same. Finally, when the sand grains start to look like giant boulders, the pattern breaks, but each boulder is following some simple laws of physics.
In fact, we like to model little blocks because it's fun! And it has some lessons for us, mainly that a tiny movement in one place can trigger a larger movement quite far away.
But back to the pile of sand. We see that the pattern of sand failures is self-similar on all scales, but with a big BUT! That is, the self-similarity only holds between two size scales: that of the whole sand pile, and the size of the individual sand grain.
The concept of two limiting scales really screws up a lot of earthquake people, but I suppose they'll figure it out one day. :) We aren't too sure what the largest scale is (somewhere around a few thousand km), but we do know it varies for each earthquake mechanism. What I find amazing is how small the scale can get. We find that rock bursts in mines behave almost exactly the same as earthquakes, and that rock in a testing machine also shows classical earthquake behaviour to the grain scale. So, I'm fairly confident to state that power law (self similarity) holds from the micro to the mega earthquakes.
So if the entire side of Peru is one big foot in the bathtub, it is composed of smaller feet, which are in turn compose of even smaller feet, down to the tiniest grain. At various times, each foot slips on the bathtub. If you are carefully monitoring the feet with seismometers, you see lots of little slips setting up for a bigger foot. In fact, very roughly, you need about 10 little feet to completely slip, for a foot ten times bigger, and about 30 time more energy when it slips.
After millions of slips, the biggest one decides to go. It is your biggest foot that does most of the damage, and uplifts the mountains. Those little guys are just a necessary side-show. Is the M8 earthquake in Peru the biggest foot? Most likely not, since that area is know for M9's.
In Ontario, what is our biggest foot? It's probably the dimension of the Hamilton Fault zone, which might be around M6.5. When will that foot drop?
If you recall, I left you asleep at the point of wonder why we have earthquakes at all in Eastern North America (ENA). Really, if the continent is one big massive piece of tombstone granite, then any stress-relieving earthquake should just carve a 'stress-hole' like drilling a mine.
Once this giant Tim Hortons donut gets formed, the remaining rock arches around it, and leaves a perfectly stable structure, with an extinct fault in the middle. This doesn't happen on the plate margins, with all those plates sliding past each other, like those sliding number puzzles we had as kids. For the equivalent, we would need mountain ranges or visible fault sliding to keep the similar ENA earthquake hotspots going for a few million years.
Take a typical fault zone trying to grow up in ENA. It starts with a fractured weak spot, perhaps reactivated by the modern stress field. Eventually (perhaps), the shear stress builds up along a fracture, and the bath-tub feet let go! The fractured rock behaves exactly the same as in California or Peru.
But that's it! Our poor little earthquake has shot its load. The feet have lost their stress, and the surrounding rock has clamped up on our poor little fellow. He can't grow up...
That is, if our earthquake follows conventional thinking for ENA earthquakes. But no, our earthquake fault zone is smarter than that, it is following Harold's original thinking, which doesn't get into the university cartel, because they all got tenure!
Once our earthquake has caused its bump (like a Utah coalmine!), it looks around and sees what it has done, which is to freshly fracture a lot more rock. Its seismic effort hasn't gone into mountain building, or plate sliding, it's gone into fracture surface energy! The academics never thought of that!
But this isn't enough for Quakey (like that name?), in its battle against the implacable rock. Luckily, he's (she's?) under a big hunk of water, and water slowly flows into the new fractures. Now things are cooking! The water does all sorts of wonderful things. First, the water pressure reduces the normal stress on the faults and makes them more likely to slide again. Second, the water hydrofractures and extends existing tension cracks. Finally, the fresh water is corrosive and starts chewing at the adhesion points.
Quakey has become a growing entity, like the Blob that ate New York. So, under Hamilton, New Madrid, countless other ENA locations, we have growing things, which although not actually alive, can give a darn good account of themselves!
As Quakey grows, he can tap into more stress from the surrounding rock, just like we were excavating a new Utah coal mine (or an underground nuclear waste thingie!). He gives many signs of his growth, lots of little earthquakes, just like his bigger plate margin brothers. All the bathtub feet are working, and eventually there is a large, scale-limited earthquake. The process begins again for a bigger earthquake!
Quakey may start as a simple thrust fault along a pre-existing fracture, but soon suffers growing pains. The old fracture provides the water, but a simple thrust fault isn't enough to suck out all the stress from the surround rock. In order to avoid another stress lockup, he must start developing shear wings, which produce strike-slip earthquakes. When he eventually grows into a monster, he resembles the New Madrid fault system.
All the time, these zones are sending the signals to prove Harold is right, and the others are wrong, but the scientists and politicians are too cheap to provide the detailed seismic monitoring that is required. Only the Southern Ontario Seismic Network probably has sufficient horsepower and density, but the Hamilton zone is just a baby!
Everyday, these zones try to show themselves. They send typical 'fluid injection' earthquakes, they mix thrust and strike-slip mechanisms, and they only show up under bodies of water. But without monitoring, the world goes on arguing with Harold. :)
Seismic Analysis
Traditional seismic analysis is rather long in the tooth. The latest earthquakes have shown the importance of large transients.
(A consolidated series from my blog Ontario Geofish.)
My next series will be on seismic analysis. I wrote a fair piece of that Wiki article, and I've been involved with the trade for many years. For those purists, I'm referring to civil seismic analysis, which is the study of soils and structures to seismic shaking.
The prime motivator for the start of seismic analysis was the observation that buildings shimmered and shook in earthquakes, like a dancer on the good juice! As well, it was noted that buildings on soft soils would act extra bad, if both the soil and building had matching resonance frequencies.
Thus, seismic analysis started down the road of studying resonance, and never really got off that streetcar! And what better way to study resonance than to muck up everybody's minds with eigenvalues! This has been designed as mental torture for young engineers, and filters them out by killing them! You young'uns might have to learn this crap, but it is not conducive to good thinking. I have met many people who spout eigenvalues, and eigenvectors, and have no clue what they are talking about.
Early seismic analysis was also contaminated by the California experience, where most historic earthquakes were long rumbly things that totally activated the soil basins, and thus resembled long sinusoids of varying frequencies. They could characterize these sinusoids with the simple mechanical contrivance of a series of oscillators. Thus, you could measure the maximum motion of a 1 Hz oscillator, a 5 Hz one, etc. Since engineers love everything mechanical, you could actually build one of these 'response spectrum' boxes, and they were used for years in nuclear power plants.
I'm just going into these ancient assumptions, because they are still used today, simply because they are 'tradition'. If you are ever in a position to be snowed by a fancy seismic analysis, simply ask what are the underlying assumptions, and how do they relate to modern science? They will just die!
In this series, I will attempt to do something never done before by an engineer on a blog: I will start a legitimate seismic analysis from scratch, using programs I've never used before! I take the risk of looking like a complete fool, which is something that the 'distinguished' people would never do. I'm only keeping a 'live blog' to motivate me to do something that seriously hurts my brain!
Here, we pay homage to our hero in this difficult endeavor.
That's right, it's Shrek! That series of movies did more for the science of physics modeling, than 30 years of engineering. Those guys just recently won an Oscar for particle dynamics, which is used for simulating water, smoke, clouds, explosions, etc. They use big clusters of Linux computers, and each run probably uses more power than any seismic analysis. Unfortunately, all the smart guys are either working for Hollywood, or doing crash analysis for cars, and there isn't much literature available.
So, with Shrek in mind, we will take a totally different route for seismic analysis, starting with a clean slate, and using modern computing techniques. With an iPod being more powerful than the computers I used 30 years ago, we have no need for the old 'compute saving' shortcuts.
Now we start. Think of very small chunk of concrete, suspended in the air. This particle is subjected to various forces, such as gravity. It has a defined mass, measured in kilograms. Newton gave us a very great gift, to calculate what this particle will do next: F = M a, or a = F/M. That means the acceleration of the particle (defined as a 3D vector), will merely be a vector sum of all the forces divided by the mass (keeping consistent units is a bitch!).
Although this particle would love to be in a Hollywood explosion, for us, it is embedded in a civil structure, and will only fly in an earthquake, if it is made of Montreal Mafia concrete! But, assuming a normal structure, this 'hunk' has restraining forces. We model this as simple springs, all around the hunk, so that if it moves to the right, the spring force increases to push it back to the left.
In fact, this is all we really need to model the physics, except that we are now going to thousands of hunks. If the conglomeration (structure) is as boring as a Toronto suburb, then it's not moving. For that, we need a 'forcing function', such as would be provided by an earthquake.
The Shrekians perfected a marvelous technique of explicit time domain modeling. This what I used with my own computer code 30 years ago, and had I been smarter, I'd be rich! With it, we make the time steps very small, so that we can predict exactly what our hunk will do in the next time step, by summing the forces in this time step. This type of calculation is 'explicit' in that we don't have to do any fancy recursion or anything, and thus lends itself to be solved by large computer clusters.
In the next article, I shall finally open up a computer program, that I have never seen before, and have no great confidence in myself, to get it working!
And so we plunge into the cold water. I have chosen the Impact explicit finite elements program, since it is closest to what I have worked with before, and has many neato features. As well, I finally got it to look normal on my system, so I am encouraged.
As well as my earlier home-spun efforts, I had a chance to work with Ansys Ls-dyna, which is a horrendously expensive commercial program, that I managed to con the bosses into getting! Unfortunately, it only worked on the sleazy Windows boxes, beloved of all dysfunctional techno-bureaucracies, and I couldn't go far with it. Impact is written in Java, and has the ability to cluster, so it is interesting. I don't know if it is still being supported, since the last posts look rather old.
I shall now open it and work through the tutorial.
OH MY GOD! It's working perfectly! I've created a steel plate, and it has built-in materials! That was such a bastard with the commercial codes! Here's my plate. I can't stand it anymore, I need a snooze!
Okay, we've got our steel plate, but if we gave it a shove, it would travel through space, whirling and spinning like a US spy satellite! That's the nice thing about Shrekian Analysis, we could model the satellite spinning through space, and then have the missile blow it up into a zillion pieces!
But we don't want that now. We want the plate to stay in one place so that we can deform it. That means we have to hammer in some sky-nails! These are very special, in that they nail an object to absolute co-ordinates, in the middle of the sky. I think they must penetrate into a parallel universe! In more mundane terms, they are called constraints.
I will now enter the program, and continue the tutorial.
Okay, I have entered the constraints and applied the loads.
The final step is to run the model. Fingers crossed!
OMG, it's running! Only using one processor, might be able to fix that when clustering.
It's done! Now, it should look like this.
That's a big, folded pop-can. Instead, my looks like this.
Which means that it didn't crumple, it just shattered and pieces flew all over the place! I most likely set the material properties wrong, more like glass than steel. Back to the drawing board!
This is fun! I'll keep mucking with it, until I get the tutorial right. Then, we attempt to put in a dynamic constraint to get some wave propagation, and we are on our way to seismic analysis!
I now have wave propagation!
I have initiated a 'hit' constraint on the middle bottom nodes. The wave will now start to propagate into the medium.
And the last shot.
Note the leading 'fuzz' from the main pulse. This is most likely an instability propagating directly per time step. I used to get this all the time. The solution is to 'shape' the input curve into a cosine wavelet (smooth bump!), and to decrease the time interval. All in all, I am amazed at how quickly this runs, and I can specify 2 processors if I want to!
I was working on gmsh which is a better modeler. I intend to eventually model soil on rock, a structure on rock, and a structure on soil. Based on my previous modeling, it will show how the 'old guys' have it all wrong when they deal with structural resonance, mainly because of those deep horrible assumptions.
Still moving along. Got sidetracked with model generation, which was a big waste of time. Figured out how to animate an impact.
This is the max displacement vector. You can see the fundamental starting to come in, which will be the block pulsing up and down. I'm always fascinated to watch the transients become the fundamentals. All of traditional seismic analysis skips the transients.
ps. 1st few frames are at the last.
(A consolidated series from my blog Ontario Geofish.)
My next series will be on seismic analysis. I wrote a fair piece of that Wiki article, and I've been involved with the trade for many years. For those purists, I'm referring to civil seismic analysis, which is the study of soils and structures to seismic shaking.
The prime motivator for the start of seismic analysis was the observation that buildings shimmered and shook in earthquakes, like a dancer on the good juice! As well, it was noted that buildings on soft soils would act extra bad, if both the soil and building had matching resonance frequencies.
Thus, seismic analysis started down the road of studying resonance, and never really got off that streetcar! And what better way to study resonance than to muck up everybody's minds with eigenvalues! This has been designed as mental torture for young engineers, and filters them out by killing them! You young'uns might have to learn this crap, but it is not conducive to good thinking. I have met many people who spout eigenvalues, and eigenvectors, and have no clue what they are talking about.
Early seismic analysis was also contaminated by the California experience, where most historic earthquakes were long rumbly things that totally activated the soil basins, and thus resembled long sinusoids of varying frequencies. They could characterize these sinusoids with the simple mechanical contrivance of a series of oscillators. Thus, you could measure the maximum motion of a 1 Hz oscillator, a 5 Hz one, etc. Since engineers love everything mechanical, you could actually build one of these 'response spectrum' boxes, and they were used for years in nuclear power plants.
I'm just going into these ancient assumptions, because they are still used today, simply because they are 'tradition'. If you are ever in a position to be snowed by a fancy seismic analysis, simply ask what are the underlying assumptions, and how do they relate to modern science? They will just die!
In this series, I will attempt to do something never done before by an engineer on a blog: I will start a legitimate seismic analysis from scratch, using programs I've never used before! I take the risk of looking like a complete fool, which is something that the 'distinguished' people would never do. I'm only keeping a 'live blog' to motivate me to do something that seriously hurts my brain!
Here, we pay homage to our hero in this difficult endeavor.
That's right, it's Shrek! That series of movies did more for the science of physics modeling, than 30 years of engineering. Those guys just recently won an Oscar for particle dynamics, which is used for simulating water, smoke, clouds, explosions, etc. They use big clusters of Linux computers, and each run probably uses more power than any seismic analysis. Unfortunately, all the smart guys are either working for Hollywood, or doing crash analysis for cars, and there isn't much literature available.So, with Shrek in mind, we will take a totally different route for seismic analysis, starting with a clean slate, and using modern computing techniques. With an iPod being more powerful than the computers I used 30 years ago, we have no need for the old 'compute saving' shortcuts.
Now we start. Think of very small chunk of concrete, suspended in the air. This particle is subjected to various forces, such as gravity. It has a defined mass, measured in kilograms. Newton gave us a very great gift, to calculate what this particle will do next: F = M a, or a = F/M. That means the acceleration of the particle (defined as a 3D vector), will merely be a vector sum of all the forces divided by the mass (keeping consistent units is a bitch!).
Although this particle would love to be in a Hollywood explosion, for us, it is embedded in a civil structure, and will only fly in an earthquake, if it is made of Montreal Mafia concrete! But, assuming a normal structure, this 'hunk' has restraining forces. We model this as simple springs, all around the hunk, so that if it moves to the right, the spring force increases to push it back to the left.
In fact, this is all we really need to model the physics, except that we are now going to thousands of hunks. If the conglomeration (structure) is as boring as a Toronto suburb, then it's not moving. For that, we need a 'forcing function', such as would be provided by an earthquake.
The Shrekians perfected a marvelous technique of explicit time domain modeling. This what I used with my own computer code 30 years ago, and had I been smarter, I'd be rich! With it, we make the time steps very small, so that we can predict exactly what our hunk will do in the next time step, by summing the forces in this time step. This type of calculation is 'explicit' in that we don't have to do any fancy recursion or anything, and thus lends itself to be solved by large computer clusters.
In the next article, I shall finally open up a computer program, that I have never seen before, and have no great confidence in myself, to get it working!
And so we plunge into the cold water. I have chosen the Impact explicit finite elements program, since it is closest to what I have worked with before, and has many neato features. As well, I finally got it to look normal on my system, so I am encouraged.
As well as my earlier home-spun efforts, I had a chance to work with Ansys Ls-dyna, which is a horrendously expensive commercial program, that I managed to con the bosses into getting! Unfortunately, it only worked on the sleazy Windows boxes, beloved of all dysfunctional techno-bureaucracies, and I couldn't go far with it. Impact is written in Java, and has the ability to cluster, so it is interesting. I don't know if it is still being supported, since the last posts look rather old.
I shall now open it and work through the tutorial.
OH MY GOD! It's working perfectly! I've created a steel plate, and it has built-in materials! That was such a bastard with the commercial codes! Here's my plate. I can't stand it anymore, I need a snooze!
Okay, we've got our steel plate, but if we gave it a shove, it would travel through space, whirling and spinning like a US spy satellite! That's the nice thing about Shrekian Analysis, we could model the satellite spinning through space, and then have the missile blow it up into a zillion pieces!
But we don't want that now. We want the plate to stay in one place so that we can deform it. That means we have to hammer in some sky-nails! These are very special, in that they nail an object to absolute co-ordinates, in the middle of the sky. I think they must penetrate into a parallel universe! In more mundane terms, they are called constraints.
I will now enter the program, and continue the tutorial.
Okay, I have entered the constraints and applied the loads.
The final step is to run the model. Fingers crossed!OMG, it's running! Only using one processor, might be able to fix that when clustering.
It's done! Now, it should look like this.
That's a big, folded pop-can. Instead, my looks like this.
Which means that it didn't crumple, it just shattered and pieces flew all over the place! I most likely set the material properties wrong, more like glass than steel. Back to the drawing board!This is fun! I'll keep mucking with it, until I get the tutorial right. Then, we attempt to put in a dynamic constraint to get some wave propagation, and we are on our way to seismic analysis!
I now have wave propagation!
I have initiated a 'hit' constraint on the middle bottom nodes. The wave will now start to propagate into the medium.
And the last shot.
Note the leading 'fuzz' from the main pulse. This is most likely an instability propagating directly per time step. I used to get this all the time. The solution is to 'shape' the input curve into a cosine wavelet (smooth bump!), and to decrease the time interval. All in all, I am amazed at how quickly this runs, and I can specify 2 processors if I want to!I was working on gmsh which is a better modeler. I intend to eventually model soil on rock, a structure on rock, and a structure on soil. Based on my previous modeling, it will show how the 'old guys' have it all wrong when they deal with structural resonance, mainly because of those deep horrible assumptions.
Still moving along. Got sidetracked with model generation, which was a big waste of time. Figured out how to animate an impact.
This is the max displacement vector. You can see the fundamental starting to come in, which will be the block pulsing up and down. I'm always fascinated to watch the transients become the fundamentals. All of traditional seismic analysis skips the transients.
ps. 1st few frames are at the last.
Great Hotspot Controversy
Hotspots are relatively stationary in the earth, with respect to the moving tectonic plates. But how deep are they really
I just dipped into this the other day. Seems this is as 'hot' as it gets in geology-land, almost as big as the dinosaur killer thing! Some of this is outlined in Mantleplumes. (Might be considered 'unreadable' by some!)
I've always loved hotspots. They were right there from the beginning of plate tectonic theory, and the great Tuzo Wilson, whom I had the pleasure of meeting personally, made great use of them.
In my early days, hotspots were made out to be great magical things that shot out from the deep mantle, and stayed absolutely stationary with respect to the inner earth. Of course, the plates slooshed all over the goopy layer, but the hotspots stayed resolute and pure. The plates slid over these markers, and showed the absolute motion of the plates. The Hawaian chain is an example of this.
I was an 'absolute' believer in this theory, since it was like the thermal 'Fist of God '.
Unfortunately for us supporters of 'Spiritual Purity in Plate Tectonics', there wasn't a shred of evidence for this theory. And over the years, the nasty reality of Science has chipped away at the stone edifice. There's no chemistry to prove it, no deep seismic scans, no nothing.
Alack a day! What to do, what to do? Well, ditch this old crap and go on to something new! It has been noticed that hotspots are born, have some fun, and die. As well, they have never scanned lower than the goopy layer. They stay in one place more than the plates, but they do move around.
This gives rise to the 'new' theory: that they are not 'magical' at all! They are a consequence of everyday old plate tectonics!
Seems when the old oceanic crust subducts, as over in Vancouver, there are some wild-blasty volcanoes (like Chaiten), that live off the cooked water from the dessicating crust. And so that old dry crust has been ignored and forgotten. But it bites back! Seems all this old crust hangs around at the bottom and cooks, and melts, like chocolate. When there is a whole giant pool of it all hot and bubbly, it bursts out. Normally, this process can be activated by some sort of tension, such as plate separation, or continental drift.
The sub-continent of India really opened one up, which became the Deccan Traps, and the same for Yellowstone. If these things open up under a continent, all hell breaks loose, as the continental rocks are cooked and explode out with world-wide, extinction-type consequences. Believe me, we don't want this happening before the Sun blows up!
Once started, the hotspot sticks around for quite a while and the plates ride over them. This happened in Quebec with the formation of Mount Royal, and the whole line of similar mountains, down to Boston, and out into the sea.
I just dipped into this the other day. Seems this is as 'hot' as it gets in geology-land, almost as big as the dinosaur killer thing! Some of this is outlined in Mantleplumes. (Might be considered 'unreadable' by some!)
I've always loved hotspots. They were right there from the beginning of plate tectonic theory, and the great Tuzo Wilson, whom I had the pleasure of meeting personally, made great use of them.
In my early days, hotspots were made out to be great magical things that shot out from the deep mantle, and stayed absolutely stationary with respect to the inner earth. Of course, the plates slooshed all over the goopy layer, but the hotspots stayed resolute and pure. The plates slid over these markers, and showed the absolute motion of the plates. The Hawaian chain is an example of this.
I was an 'absolute' believer in this theory, since it was like the thermal 'Fist of God '.
Unfortunately for us supporters of 'Spiritual Purity in Plate Tectonics', there wasn't a shred of evidence for this theory. And over the years, the nasty reality of Science has chipped away at the stone edifice. There's no chemistry to prove it, no deep seismic scans, no nothing.
Alack a day! What to do, what to do? Well, ditch this old crap and go on to something new! It has been noticed that hotspots are born, have some fun, and die. As well, they have never scanned lower than the goopy layer. They stay in one place more than the plates, but they do move around.
This gives rise to the 'new' theory: that they are not 'magical' at all! They are a consequence of everyday old plate tectonics!
Seems when the old oceanic crust subducts, as over in Vancouver, there are some wild-blasty volcanoes (like Chaiten), that live off the cooked water from the dessicating crust. And so that old dry crust has been ignored and forgotten. But it bites back! Seems all this old crust hangs around at the bottom and cooks, and melts, like chocolate. When there is a whole giant pool of it all hot and bubbly, it bursts out. Normally, this process can be activated by some sort of tension, such as plate separation, or continental drift.
The sub-continent of India really opened one up, which became the Deccan Traps, and the same for Yellowstone. If these things open up under a continent, all hell breaks loose, as the continental rocks are cooked and explode out with world-wide, extinction-type consequences. Believe me, we don't want this happening before the Sun blows up!
Once started, the hotspot sticks around for quite a while and the plates ride over them. This happened in Quebec with the formation of Mount Royal, and the whole line of similar mountains, down to Boston, and out into the sea.
Catastrophic Power Law and Everyday Life
The relationship between major disasters and self-similarity.
A recent massive Toronto propane explosion, and the city's pitiful response has inspired me to resurrect my Claptrap article and beef it up for a Knol. I went back to it, after the big Canadian Listeria disaster.
Power Law is the fundamental force behind most large-scale disasters, such as earthquakes, and industrial accidents. It is a consequence of the fractal, self-similar ordering of most natural systems, and human societies. Disasters are a consequence of Power Law coming against the natural linear thinking of the human brain.
Fractal Ordering and Nature
Take a look at most natural scenes, and you will find them pretty. A rugged coastline, a cliff face, a beautiful tree, and a sunflower. All of them appeal to our sense of proportion.
These are all fractal patterns, and are created from the application of simple growth rules, applied over and over again. When this concept first came out, I studied it intensely, and could never get over the complicated math that accompanied it. I dismissed it as merely a way to make pretty pictures. Over the years, I have become to realize that it is one of the most fundamental forces of nature, and that the concept is very simple.
Take an everyday tree. You can derive some very simple rules for making that tree, simply by specifying the degree of branching (two, three, etc), the length of the base twigs, and then state that a new sprout is simply another tree growing off the shaft. The tree can become immensely complex! The 'roughness' of the tree is a consequence of the branching rules.
Geology is my love, and here's where fractals totally rule! Take this pretty picture, for example.
You can't tell the scale! Is it a polished mineral on a ring? Is it a rock face? It is actually a satellite image from the ASTER collection. That is why all photos of geology have something applied for scale, such as a notebook or a person.
Fractals have some important attributes that affect us in everyday life. Look at the pretty clouds, nice and fluffy. You can zoom in on the clouds, and still see the same patterns as in the larger clouds. Most clouds have the same fractal roughness, but limiting dimensions are important here! There is no practical limit on the small side, since you could zoom in forever, and it would be fractal, until you hit the scale of condensation droplets. But on the large side, there are varying limits.
On a nice day, the fluffy clouds are limited to a certain size, before the fractal pattern breaks down. In Ontario this summer, we have had rough fractal clouds with no limit on the large side. That means you constantly experience all types of weather on the same day! The cloud patterns are perfectly fractal on the satellite and radar. The sunny breaks and the rain follow Power Law. Lots of little ones, and then some super big thunderstorms or sunny periods. Very pretty cloud formations, very depressing weather!
Human societies love fractals. We organize ourselves in families, villages, regions, countries, etc. Most companies also organize in self-similar hierarchies. Every smaller group resembles the larger group as a whole.
Power Law
Power Law can be a truly horrible thing. It proceeds exactly like earthquakes. One day you are chugging along with just some minor rumblers, and POW! the Big One hits. That is because each smaller Magnitude is ten times more frequent, and each Magnitude upgrade is 30 times more damaging. This results in rare, damaging events that are totally not foreseen by most human minds. Think of it, just 1% of a given number of earthquakes has a 1000 times the hitting power!
This happens with all power-law disasters, even those that are totally man-made. It is normal human comprehension to think of things in linear terms - the pot is nearly boiling, a little more and it starts to boil. We always think we are going to get some warning of trouble. We always rely on a linear extrapolation of our past experience: "Oh, this hurricane could be a bit worse than last year's."
Inevitable Power-Law Disasters
Even earthquake and hurricane disasters, are in a sense man-made. Earthquakes make buildings fall on people, hurricanes breach levies. I find that power-law disasters are inevitable when you have an unstable fractal organization (self-similar).
Take a stable fractal organization: a tree. A twig breaks off, and the whole tree does not become weaker, in fact it is more stable because of the lightened load. But introduce a linear weakening mechanism, such as rot or disease, and then things become interesting. The branches falling down become power law. You get a distribution of many small branches falling, with one in ten being significantly larger. As the owner of the house right under it, you better chop it down soon, because there is a chance of major branches, or the whole tree falling.
A totally self-similar organization can act as a tree. Under certain circumstances, each small failure can set things up for a larger failure, especially if everybody acts in 'crisis mode', and just puts in short-term solutions. As an example, consider NASA before the first Shuttle failure. Everything was self-similar right from the top, everybody engaged in 'group think', and the failures were building up in a power law distribution. There were lots of minor failures of the o-rings.
How can this be prevented? First of all, as with earthquakes, by careful monitoring. Are the failures following power law? This is very difficult to do from the outside, since nearly all such self-similar organizations hide these things, from both themselves, and the press. Take for example, the French or Japan nuclear organizations, they would never reveal the countless minor incidents.
The public could demand more transparency from such organizations. The only cure is to cut down the maximum fractal dimension, by adding some 'hard blocks', or transparency. I believe that NASA is now doing this.
A recent massive Toronto propane explosion, and the city's pitiful response has inspired me to resurrect my Claptrap article and beef it up for a Knol. I went back to it, after the big Canadian Listeria disaster.
Power Law is the fundamental force behind most large-scale disasters, such as earthquakes, and industrial accidents. It is a consequence of the fractal, self-similar ordering of most natural systems, and human societies. Disasters are a consequence of Power Law coming against the natural linear thinking of the human brain.
Fractal Ordering and Nature
Take a look at most natural scenes, and you will find them pretty. A rugged coastline, a cliff face, a beautiful tree, and a sunflower. All of them appeal to our sense of proportion.
These are all fractal patterns, and are created from the application of simple growth rules, applied over and over again. When this concept first came out, I studied it intensely, and could never get over the complicated math that accompanied it. I dismissed it as merely a way to make pretty pictures. Over the years, I have become to realize that it is one of the most fundamental forces of nature, and that the concept is very simple.
Take an everyday tree. You can derive some very simple rules for making that tree, simply by specifying the degree of branching (two, three, etc), the length of the base twigs, and then state that a new sprout is simply another tree growing off the shaft. The tree can become immensely complex! The 'roughness' of the tree is a consequence of the branching rules.
Geology is my love, and here's where fractals totally rule! Take this pretty picture, for example.
You can't tell the scale! Is it a polished mineral on a ring? Is it a rock face? It is actually a satellite image from the ASTER collection. That is why all photos of geology have something applied for scale, such as a notebook or a person.
Fractals have some important attributes that affect us in everyday life. Look at the pretty clouds, nice and fluffy. You can zoom in on the clouds, and still see the same patterns as in the larger clouds. Most clouds have the same fractal roughness, but limiting dimensions are important here! There is no practical limit on the small side, since you could zoom in forever, and it would be fractal, until you hit the scale of condensation droplets. But on the large side, there are varying limits.
On a nice day, the fluffy clouds are limited to a certain size, before the fractal pattern breaks down. In Ontario this summer, we have had rough fractal clouds with no limit on the large side. That means you constantly experience all types of weather on the same day! The cloud patterns are perfectly fractal on the satellite and radar. The sunny breaks and the rain follow Power Law. Lots of little ones, and then some super big thunderstorms or sunny periods. Very pretty cloud formations, very depressing weather!
Human societies love fractals. We organize ourselves in families, villages, regions, countries, etc. Most companies also organize in self-similar hierarchies. Every smaller group resembles the larger group as a whole.
Power Law
Power Law can be a truly horrible thing. It proceeds exactly like earthquakes. One day you are chugging along with just some minor rumblers, and POW! the Big One hits. That is because each smaller Magnitude is ten times more frequent, and each Magnitude upgrade is 30 times more damaging. This results in rare, damaging events that are totally not foreseen by most human minds. Think of it, just 1% of a given number of earthquakes has a 1000 times the hitting power!
This happens with all power-law disasters, even those that are totally man-made. It is normal human comprehension to think of things in linear terms - the pot is nearly boiling, a little more and it starts to boil. We always think we are going to get some warning of trouble. We always rely on a linear extrapolation of our past experience: "Oh, this hurricane could be a bit worse than last year's."
Inevitable Power-Law Disasters
Even earthquake and hurricane disasters, are in a sense man-made. Earthquakes make buildings fall on people, hurricanes breach levies. I find that power-law disasters are inevitable when you have an unstable fractal organization (self-similar).
Take a stable fractal organization: a tree. A twig breaks off, and the whole tree does not become weaker, in fact it is more stable because of the lightened load. But introduce a linear weakening mechanism, such as rot or disease, and then things become interesting. The branches falling down become power law. You get a distribution of many small branches falling, with one in ten being significantly larger. As the owner of the house right under it, you better chop it down soon, because there is a chance of major branches, or the whole tree falling.
A totally self-similar organization can act as a tree. Under certain circumstances, each small failure can set things up for a larger failure, especially if everybody acts in 'crisis mode', and just puts in short-term solutions. As an example, consider NASA before the first Shuttle failure. Everything was self-similar right from the top, everybody engaged in 'group think', and the failures were building up in a power law distribution. There were lots of minor failures of the o-rings.
How can this be prevented? First of all, as with earthquakes, by careful monitoring. Are the failures following power law? This is very difficult to do from the outside, since nearly all such self-similar organizations hide these things, from both themselves, and the press. Take for example, the French or Japan nuclear organizations, they would never reveal the countless minor incidents.
The public could demand more transparency from such organizations. The only cure is to cut down the maximum fractal dimension, by adding some 'hard blocks', or transparency. I believe that NASA is now doing this.
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