Saturday, March 21, 2015
Deep M4.0 Oklahoma earthquake
Nothing to see here, really. But, I always look on the bright side. This was a directed strike-slip and I'm calling it deep. In fact, all the latest significant earthquakes have been deep, ushering in the new phase of depth extension. This was too small to produce regional stress relief, and an M2.9 happened shortly afterwards.
I've been saying that this mechanism is exactly what happened when New Madrid was a baby. As long as the earthquakes stay in the upper 5 km, we can only go as high as an M6. When the events go down to 30 km, then we can get a New Madrid style M7. Such an event would destroy cheap high-rise condos on swamps all over ENA. You should live, though. :)
Update: Back to a heavy chatter. The tremor worms are eating away the rock. :)
Update2: Yeah, the usgus is back to the beach for M4's. Somebody must have been surfing. :)
Almost pure thrust. At least 10 km deep to spread out the PGV so much. They don't go below 5 on their very rough calculations. We're into M6.2 territory now.