According to seismologist Bill Ellsworth, lead author of a recent USGS study, there has been a “remarkable increase” in earthquakes magnitude 3.0 or greater in the midwest and southern plains in the last few years. As it turns out, these quakes are “almost certainly” man-made. The likely cause of cause of all these quakes is a by-product of hydraulic fracturing (fracking) the drilling process by which oil and gas companies shoot a slurry of water, sand, and chemicals into deep shale formations at extremely high pressure to “unlock” the fossil fuels locked within. Fracking has sparked a natural gas boom of historic proportions causing prices to drop from nearly $15 per million BTU in 2005, to less than $2 today.
It isn’t the drilling itself that is causing these fracking quakes. Actually, they are caused by the disposal of fracking wastewater. The process requires a ridiculous amount of water. A single fracking well pad (which supports up to 16 individual wells) can use over 80 million gallons of water a week! That water is not cheap to treat and is often injected deep into the earth into supposedly stable sandstone formations. Here, that water acts as a sort of lubricant, allowing (generally) small faults within the rock to slip, which produces the temblors not normally associated with Dallas or eastern Ohio.
While unsettling, the quakes in Ohio, Texas, and Oklahoma are unlikely to cause significant damage. The faults in these areas are very small, and the underlying geography is stable. As fracking moves into less stable geography, however, the earthquake risk could rise significantly. A geothermal energy project in Basel, Switzerland, which used a process very similar to fracking, caused a 3.4 magnitude earthquake which resulted in some minor damage. While that quake was not particularly large, a quake on the same fault in 1356 completely destroyed the city. Swiss citizens were alarmed, and work on the project was halted. Much, much scarier was the 2008 Sichuan earthquake in western China which killed approximately 70,000 people. According to Fan Xiao of the Sichuan Geology and Mineral Bureau, it is “very likely” that the construction and filling of the Zipingpu dam and reservoir in 2004 led to the disaster. The dam was positioned on top of a fault line, and the combination of the weight of the lake, and water seeping into the rock probably caused the quake.
Now, drilling companies are moving into fracking California, which possesses the largest shale formation in the US, and, of course, a problematic geologic history. Hopefully, the release of this study will give pause to drillers eager to explore gas deposits in Los Angeles itself. We cannot allow fracking drilling companies to cause the “Big One.”