This Climate Progress piece posted on Wed Nov 2nd seems eerily prescient given what just happened in Oklahoma:

A previously unreported study out of the Oklahoma Geological Survey has found that hydraulic fracturing may have triggered a swarm of small earthquakes earlier this year in Oklahoma. The quakes, which struck on Jan. 18 in a rural area near Elmore City, peaked at magnitude 2.8 and caused no deaths or property damage.

The study, currently being prepared for peer review, follows news today that Cuadrilla Resources, a British shale gas developer, has found that it was ‘highly probable’ its fracturing operations caused minor quakes of magnitude 2.3 and 1.5 in Lancashire, England. The Cuadrilla study could complicate the expansion of hydraulic fracturing for shale gas in risk-averse Europe, where France has already banned the practice.

UPDATE: More info from other sites:

Major Earthquake Hits Oklahoma

Oklahoma was hit by what is being called a record-breaking 5.6-magnitude earthquake last night, and it is the second in close succession. This has brought up questions about the practicing of fracking- or hydraulic fracturing- in the state…There are normally about fifty earthquakes in Oklahoma every year, but there has been a sharp increase in recent years with there being 1,047 quakes last year. There is no official explanation as to why this has begun to happen.

What Caused the Oklahoma Earthquakes

The New Madrid Fault line is too far to the east, and since the quake was centered just east of Oklahoma City in the town of Sparks, saying it’s a result of the fault wouldn’t make sense. What cause does make sense? Fracking.

The Oklahoma Geological Survey by Austin Holland was published recently, and it states clearly that fracking is one of the causes for earthquakes. When you inject the earth with saltwater to break up the shale beneath the earth, you’re creating an instability in the crust that results in sudden and sometimes extreme movement. In other words, the earth sinks a little where the fracking occurs. Doesn’t anyone see anything wrong with this? Oil companies are admitting they’re damaging the earth, damaging homes, infrastructure, and possibly risking lives…all for the sake of natural gas and oil.

Just to illustrate the point, between 1977 and 2008, there were only 28 earthquakes in Oklahoma: less than 1 per year. Between 2009 and 2010, the state experienced 134 earthquakes: an average of 95 quakes per year. That’s a huge difference. And it simply can not be attributed to a fault line or natural causes. Even the British energy company, Cuadrilla Resources, admits that fracking is the most likely cause of increased incidents of earthquakes in the area.