The fact that Leaf had mentioned "gas companies" and their possible relation to sysmic activity encouraged me to do some 'googling' and the following may be of some interest to you GetBiggers in OK and AK.
"Oklahoma typically had about 50 earthquakes a year until 2009, then the number spiked, and 1,047 quakes shook the state last year (2010). That's a hell of a big spike!
Arkansas also has seen a big increase in earthquake activity which residents have blamed on injection wells.
Natural gas companies engage in hydraulic fracturing(or fracking) use fluid to break apart shale and rock to release natural gas.
Injection wells then dispose of the fluid by injecting it back into the ground.
There are 181 injection wells in the Oklahoma county where most of the weekend earthquakes happened, said Matt Skinner, spokesman for the Oklahoma Corporation Commission, which oversees oil and gas production in the state and intrastate transportation pipelines.
But natural gas companies claim there is no proof of a connection between injection wells and earthquakes, and a study released earlier this year by an Oklahoma Geological Survey seismologist seems to back that up.
It found most of the state's seismic activity didn't appear to be tied to the wells but the study isn't conclusive."
