Fracking Fears Grow as Oklahoma Hit by More Earthquakes Than California [View all]
http://www.bloomberg.com/news/2014-07-07/oklahoma-temblors-outpace-california-as-fracking-booms.html

Austin Holland, pictured, Oklahomas seismology chief, is determined to findhe cause of an unprecedented earthquake epidemic in the state.
Squinting into a laptop perched on the back of his pickup, Austin Holland searches for a signal from a coffee-can-sized sensor buried under the grassy prairie.
Holland, Oklahomas seismology chief, is determined to find the cause of an unprecedented earthquake epidemic in the state. And he suspects pumping wastewater from oil and gas drilling back into the Earth has a lot to do with it.
If my research takes me to the point where we determine the safest thing to do is to shut down injection -- and consequently production -- in large portions of the state, then thats what we have to do, Holland said. Thats for the politicians and the regulators to work out.
So far this year, Oklahoma has had more than twice the number of earthquakes as California, making it the most seismically active state in the continental U.S. As recently as 2003, Oklahoma was ranked 17th for earthquakes. That shift has given rise to concern among communities and environmentalists that injecting vast amounts of wastewater back into the ground is contributing to the rise in Oklahomas quakes. The state pumps about 350,000 barrels of oil a day, making it the fifth largest producer in the U.S.