Slowing Earthquake Rate Could Be Tied to Increased Regulation and Decreased Oil-Field Activity

• Joe Wertz
  BioRecent Stories

  

  Joe Wertz was a reporter and managing editor for StateImpact Oklahoma from 2011-2019. He reported on energy and environment issues for national NPR audiences and other national outlets. He previously worked as a managing editor, assistant editor and staff reporter at several major Oklahoma newspapers and studied journalism at the University of Central Oklahoma.

Joe Wertz / StateImpact Oklahoma

A disposal well in northwestern Oklahoma operated by Newfield Exploration Mid-Continent.

Oklahoma is still experiencing an unusually large amount of shaking, but the rate of earthquakes recorded in 2016 is down from last year.

The slowdown is likely due to reductions in the amount of waste-fluid the oil industry is pumping into disposal wells, which are thought to be causing most of the shaking.

And there are two big reasons for those fluid volume cutbacks: Increased regulation, and a decrease in oil and gas activity, U.S. Geological Survey geophysicist Robert Williams tells USA Today‘s Ryan W. Miller:

Regulators this year increased restrictions limiting wastewater disposal and expanded the area in the state those constraints cover, Williams said. At the same time, a decrease in oil and gas activity led to a smaller volume of water being disposed of, also potentially contributing to fewer quakes, he added.

And, while the overall rate of quakes is down, Oklahoma is still shaking at historically high levels, Miller reports:

While the overall rate of earthquakes is down, the temblors are still happening regularly in Oklahoma. In the past 30 days, 26 earthquakes with a magnitude-3.0 or greater have hit the state, according to USGS data. A magnitude-4.0 rocked an area just outside Oklahoma City early Wednesday.