Tuesday, July 29, 2014
Oklahoma earthquake M4.3 - Intensity 6
This is in the upper zone. Because of the geometry of the megathrust, I posit that the earthquakes here are very shallow. But the seismometer coverage is sparse, and the error of their depth estimate is as large as the depth itself. For sure this one was shallow since there was a very narrow zone with an Intensity of 6. I believe this breaks the record for these zones.
Once again this zone shows the weird mechanism of an oblique-normal fault. I now think it is trying to create its own thrust, and these are compression-tension quakes. Whatever, these earthquakes make the fluid injection ten times easier, and the well owners are whooping it up.
Update: the oilies are laying down a news blackout. :) For I6 you'd expect somebody's plum jam to fall off a shelf, even a chimney brick to kill the hamster. But nothing.
Update2: Although there were 3 responses of Intensity 6, most people didn't feel anything, so we'll dismiss the 6 as a drunken outlier.