United States Geological Survey
Earthquakes are increasing in the central and eastern parts of the United States including West Tennessee and the risk of earthquake hazards has “significantly increased,” according to the United States Geological Survey (USGS).
For the very first time, new reports from the USGS included man-made earthquakes to its study and forecast of earthquakes. The new report shows that about 7 million people in the central and eastern parts of the U.S. could be affected by earthquakes. The chance of damage from those earthquakes is similar to that of natural earthquakes in high-hazard areas of California, the report said.
“By including human-induced events, our assessment of earthquake hazards has significantly increased in parts of the U.S.,” said Mark Petersen, chief of the USGS National Seismic Hazard Mapping Project. “This research also shows that much more of the nation faces a significant chance of having damaging earthquakes over the next year, whether natural or human-induced.”
Earthquakes in the central U.S., which the study defines as the area between the Atlantic and basically the Rocky Mountains, have increased markedly in the last six years, the study said.
Between 1973 and 2008, the average amount of earthquakes of magnitude 3.0 or higher was 24. From 2008 to 2015, the average increased to 318 per year. So far this year, there have been about 226.
Much of the increase is linked to fracking, or hydraulic fracturing, according to the USGS. The mining process injects highly pressurized water, chemicals, and waste water into the ground to break up rocks to help release petroleum, natural gas, and more.
But the main culprit isn’t the fracking itself, the USGS reported, but the wastewater byproduct. Wastewater from fracking is collected, trucked, and then injected and stored in deep underground wells, below aquifers that provide drinking water.
Tennessee did not make the USGS’s top six states at risk for increased earthquakes. Those states are Oklahoma, Kansas, Texas, Colorado, New Mexico, and Arkansas.
In the area around Memphis, 12 earthquakes have been reported to the USGS’s “Did You Feel It?” website.
For the first time, the USGS has given a one-year earthquake forecast. That forecast puts a 1 percent to 5 percent risk of earthquake damage to an area along the Mississippi River that stretches from southern Illnois almost to Memphis.