The most worrisome side effect of "fracking" is the rise of earthquakes in areas where the practice is extensive.
The latest evidence comes in the form of an article in the March 26 issue of Geology, a publication of the Geological Society of America.
Entitled "Potentially induced earthquakes in Oklahoma, USA: Links between wastewater injection and the 2011 Mw 5.7 earthquake sequence," the study was coauthored by University of Oklahoma Geophysics Professor Katie Keranen, U.S. Geological Survey geophysicist Dr. Elizabeth Cochran and Columbia University's Lamont-Doherty Earth Observatory's seismologist Dr. Heather Savage and Dr. Geoffrey Abers.
The study focused its research on seismic activity in Oklahoma over the past two years and concluded that a 4.8-magnitude earthquake centered near Prague on Nov. 5, 2011, was "induced" by the injection wells. Two subsequent earthquakes, including a 5.7-magnitude "event" the following day, was the biggest in contemporary state history, were caused by the first earthquake and existing tectonic stresses in the earth.
Oklahoma's Nov. 6, 2011 earthquake was the state's largest recorded with modern instrumentation. Two people were injured in the quake, which destroyed 14 homes, buckled pavement and was felt in 17 states, as far north as Wisconsin.
DESTROYED 14 HOMES!
Professor Keranen said during an interview that there is excellent seismic data to back up the paper's conclusions, stating, "The evidence that we collected supports this interpretation. We can say several things with certainty: That the earthquakes begin within hundreds of meters of the injection wells in the units they inject into, so spatially we don't have much doubt, there is a direct spatial link."
The methodology was thorough. The paper reported that within 24 hours of the first earthquake Dr. Keranen and Oklahoma Geological Survey research seismologist Austin Holland set up seismic recorders in the area. The Geology study reports that 1,183 aftershocks were recorded by the seismic network and subsequently examined, of which 798 were studied closely.
Farther afield, seismologists suspect that oil and gas activity may have triggered earthquakes in Texas, Arkansas, Colorado and Ohio. States have adopted differing approaches to the issue, but there is now no doubt that the seismic issue is beginning to impact state legislatures considering fracking activities. Regulators in Arkansas voted to ban injection wells from one particular region after a series of earthquakes rattled the state two years ago. Oil and gas regulators in Colorado now require a review by a state seismologist before injection well permits are issued, and Illinois has passed legislation requiring injection wells to stop operating if related earthquakes cause a public safety risk. But as of yet, earthquake risk has not impacted state fracking regulations in California, Texas, New York or Oklahoma.
In the last four years, the number of quakes in the middle of the United States surged 11-fold from the three decades prior.
The natural gas industry will do their best to deny this, but it is hard to deny the rubble of 14 homes in Oklahoma, and the shattered lives of the families who once lived in them.
