The Central Valley of California has been sinking for years. The Central Valley is a major agricultural region and for a long time, ground water has been pumped out faster than it was being replenished naturally. If there's any place that could cave in during a big earthquake, it would probably be here in California.

However, it's not "fossil" water like the Ogallala and when that's gone, it's gone. China is tapping into her fossil water as her needs expand, and Libya was also building a large project to make the desert bloom, but that might be on hold for the foreseeable future.

Actually, come to think of it, I don't think I've ever read or watched any serious warning about an empty Ogallala ever caving in, though. Maybe it's not really geologically feasible?

I'm no geologist, but when it comes to aquifers, I understand it makes more sense to think of a water saturated gravel bed, and not a vast underground cavern that fill with water, and whose emptiness might make it subject to collapse. Gravel beds can only settle so far when the water comes out of them, how far, well you need to ask a geologist.

That makes sense. Seen too many Hollywood movies about the deep underground, I guess.

I assume you could still get a gradual ground subsidence like in California as the water is pumped out, but even that probably depends on the local geology.

Very good introduction 12 minute video on making an oil/gas well.
Fracing occurs around the 6-minute point.
-Blast

p.s. "Perfing" the well is my favorite part. It goes "BOOM!!!"

I'd love to know what the projected impact of a 8.0ish earthquake on the New Madrid would mean for northeast Oklahoma. The New Madrid would seem to me (who knows nothing about geology) to be the bigger threat.

Great find! Thanks!

This graphic that I had found on Wikipedia was about the only thing I had seen that showed the projected damage "radius".

http://en.wikipedia.org/wiki/File:NMSZ_Vergleich.jpg

The first-person accounts of the New Madrid quakes of 1811-12 are quite vivid.

http://earthquake.usgs.gov/earthquakes/states/events/1811_eyewitness.php


Louisville was hit much harder than I thought.

I am reading the accounts of the 1812 earthquake. while it is impressive to read, the verbiage is very nostalgic.

Truly a pleasure to read. and the information is very enlightening.