Indiana is a state where many residents worry about the inevitability of the big one — a sizable earthquake that could rock the region.
Of course, that concern comes with the warnings of the New Madrid fault zone and the Wabash seismic zone that occasionally jolt the region with minor quakes.
But now the questions come with increasing frequency, due in great part to so-called fracking, and questions about whether that process has caused earthquakes, at this point mainly in other states. Fracking, or hydraulic fracturing, is the process in which pressurized liquid, mostly water, is forced into deep rock formations where cracks are created. Natural gas and petroleum then flow out more freely.
The subject came up recently because Indiana's oil and gas industries are studying whether hydraulic fracturing, used by many of them, can cause earthquakes.
According to the Associated Press, Hershel McDivitt, director of the Indiana Department of Natural Resources' oil and gas division, said the DNR began the study about a year ago, taking a closer look at the issue in collaboration with the Indiana Geological Survey and such states as Oklahoma, Texas, Colorado and others. As we said, they want to determine whether fracking wastewater is causing earthquakes.
McDivitt said in the AP story that "we felt that it's important for us to learn about what these other states are learning." He is a member of the group of federal and state officials, seismologists, academics and others called StatesFirst who released the report on Monday. That report is the latest work on the topic since tremors across the mid-continent began being linked to fracking in 2009.
Also, the AP cited the Indiana University-based Indiana Geological Survey as saying that "the risk of inducing earthquakes by disposing of waste fluids in deep wells is a serious and reasonable concern that deserves careful monitoring."
The report last week said about a quarter of Indiana's oil and gas wells have been fracked. Most of that has been done using 10,000 gallons or less of water and chemicals.
One of the places sure to be watched will be Gibson County in Southwestern Indiana. Between 2011 and 2014, several vertical oil wells in Gibson County were fracked using 250,000 or more gallons of water and chemicals, the AP report said.
This is surely not the last, nor should it be, of concerns about the New Madrid fault and the impact that fracking could have on it.