It just has to be from fracking.
Of course, but we'll never hear how fracking has led to lower CO2 emissions.
When doing a search I spotted this ...
Exploring the Link Between Earthquakes and Oil and Gas Disposal Wells
Oklahoma has experienced a major increase in earthquakes in recent years, including one biggie that damaged 200 buildings — and measured 5.6 magnitude — in November 2011. Swarms of quakes have continued in 2013.
ARE THE EARTHQUAKES RELATED TO OIL AND GAS DRILLING?
Several scientists have suggested that disposal wells, used to dispose of waste from some oil and gas drilling operations — including hydraulic fracturing, or “fracking” — could be the cause of the recent spike.
More than 10,000 underground injection wells were active in Oklahoma as of January 2013, data from the state Corporation Commission show. About 6,000 of these wells are a type of injection well used for enhanced oil recovery, says the commission’s injection well manager Charles Lord.
The remaining 4,400 are disposal wells used to store drilling waste, Lord says. Most of these disposal wells store waste between 10,000 and 20,000 feet underground.
WHO ARE THESE SCIENTISTS AND WHAT HAVE THEY FOUND?
A report issued last year by the U.S. Geological Survey found that most of these new earthquakes have taken place near active injection wells. Geophysicist William Ellsworth, the lead author of the report, wrote that it is completely plausible that the high water pressure often used in wastewater injections could nudge previously dormant faults out of their “locked” positions. The quakes, he wrote, are “almost certainly manmade.”
Scientists at Columbia University came to a similar conclusion after studying a rare 4.0 earthquake that took place in Ohio in 2011. The findings prompted state officials to enact broad new regulations and halt the use of any injection wells near faults. Regulators also shut down injection wells in Arkansas that same year following a cluster of quakes there, including one that measured 4.7 on the Richter scale.
University of Oklahoma seismologist Katie Keranen, who has studied a 5.6 earthquake that hit Oklahoma in November 2011, found the link between the “zone of injection” and the seismic activity “compelling.” There are three deep injection wells within two-and-a-half miles of that quake’s epicenter, according to Energy Wire.
None of these reports have claimed to have absolute proof that the two are linked. In other words, there is no scientific certainty surrounding the phenomenon.
The Oklahoma Corporation Commission, which regulates oil and gas activity in the state, points to that fact to explain its current “wait-and-see” approach. To date, Oklahoma does not have any regulations regarding injection wells and fault lines. Spokesman Matt Skinner says the commission is “keeping an open mind” about the recent and ongoing research.
http://stateimpact.npr.org/oklahoma/tag/earthquakes/