TULSA, Okla. (AP) — The number of Oklahoma earthquakes registering a magnitude of 3.0 or greater is on pace to decline for the fourth straight year after state regulators began directing oil and natural gas producers to close some wells and reduce injection volumes in others.
The Tulsa World reports that 27 earthquakes have been recorded in 2019, down from 97 by this time in 2018 and 144 in the first half of 2017.
Oklahoma’s Corporation Commission began imposing volume limits on oil companies’ disposal wells in mid-2015, after the quakes were linked to the underground injection of wastewater.
Numerous lawsuits have been filed in recent years accusing the oil companies of triggering earthquakes. The U.S. Geological Survey has calculated Oklahoma’s short-term hazard levels to be similar to active regions in California.