Up to 7 million impacted by induced seismicity
The U.S. Geological Survey (USGS) recently released a report that examined the impact of human-induced earthquakes in the U.S. and discovered that millions of U.S. residents are impacted.
Previously, the USGS focus had been only on natural earthquake hazards, but the group introduced human-induced seismic events to paint a more complete picture. Mark Petersen, Chief of the USGS National Seismic Hazard Mapping Project, said that, through the inclusion of human-induced events, the "assessment of earthquake hazards has significantly increased in parts of the U.S."
— USGS (@USGS) March 28, 2016
Earthquakes, tremors and other seismic activity caused by human activity are known collaboratively as "induced seismicity." These types of events are typically minor in scale but have been increasing in frequency in recent years due to activities like wastewater disposal, and oil and gas production from wells deep underground.
Wastewater disposal is often associated with oil and gas operations, as well, as production wastewater is often injected into wells deep underground so that the byproduct doesn't contaminate local drinking water.
Six states impacted the most
Six states saw large increases in exposure due to the inclusion of human-induced activity: Oklahoma, Kansas, Texas, Colorado, New Mexico and Arkansas.
Oklahoma and Texas topped the list of impacted regions, while scientists are also examining recent events in Alabama and Mississippi to determine whether the events were human-induced or not, and, therefore, whether those states should be added to the list.
The central region of the nation has seen the largest rise in seismic activity in the last six years, the USGS noted. From 1973 to 2008, 24 earthquakes of magnitude 3.0 and larger hit that region, on average, per year. But from 2009 to 2015, the region saw a huge jump in activity, with an average of 318 earthquakes of magnitude 3.0 per year. In 2015 alone, the region experienced 1,010 earthquakes.