Monday, August 24, 2009

Ice Age II

Ok, my brother-in-law is stuck at home for a while. He foolishly stuck his arm under a falling load, and ripped out all the tendons. Amazing what they can do with surgery, but now he's home on WorkComp. So, I suspect he gave me a huge slug of ad money, which went to a ridiculous 6 bucks today. Normally, it's 6 cents!

So I'll continue with ice modeling. I'm sure I did this before, but I can't find it. My Rock Mechanics series touched on it, but that was mostly on seismic effects. Anyway, after intensive thought, I realized the only way ice would affect granite bedrock under high horizontal stress, would be through shear, and water injection. I modeled the biggest bang I could get from an ice sheet with this approach, and it turned out that an advancing ice sheet could produce a rapid rise in ice loading, which generated underground shear stresses. If we had high-pressure melting under that sheet, then we had our high water pressures.

I assumed our ice could rise rapidly to several km's of height, limited by the strength of ice, and that the water pressure would be equal to ice load. With these numbers I could easily induce failure in a rock mass, along sub-horizontal fractures, leading out from the ice front. These could penetrate to a depth of about 1 km.

Somewhere around that time, we discovered that the underground test mine (for waste) was riddled with these open fractures down to 1 km in depth. I then cast the pronouncement that we would always find these, and that it was a hopeless search for a 'naked granite' waste repository. They promptly threw me out! :)

I then did some further work on what would be a good repository, but nobody listened.

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