TULSA, Okla. — The number of Oklahoma earthquakes registering a magnitude 3.0 or greater has declined for the third consecutive year after state regulators began directing oil and natural gas producers to close some wells and reduce injection volumes in others. The number of such quakes began declining in mid-2015 when the state Corporation Commission took action after the quakes were linked to the underground injection of wastewater, according to the Oklahoma Geological Survey. Through late December, the survey reported 196 quakes of magnitude 3.0 or stronger, down from 302 in 2017, 623 in 2016 and a record 903 in 2015. From 2008 to 2013, the state averaged 44 earthquakes of that size every year. And from 1976 to 2007, Oklahoma averaged about one quake of magnitude 3.0 or more each year.

Source: National Post January 01, 2019 16:17 UTC