Satellite data confirm man-made quakes

Oil, gas wells to blame for temblors

WASHINGTON — Scientists used radar from satellites to show that five Texas earthquakes, one reaching magnitude 4.8, were caused by injections of wastewater in drilling for oil and gas.

In 2012 and 2013, earthquakes — five of them considered significant — shook East Texas near Timpson. A team of scientists for the first time was able to track the uplifting ground movements in the earthquake using radar from satellites. A study in the journal Science on Thursday says it confirms that these were not natural, something scientists had previously said was likely using a more traditional analysis.

Study co-author Stanford University’s William Ellsworth said the technique provides a new way to determine which quakes are man-made.

The team looked at two sets of wells, eastern and western. The eastern wells were shallow and the satellite radar showed that they weren’t the culprit, but that the highvolume deeper, western ones were, Ellsworth said.

Cornell University seismologist Rowena Lohman, who wasn’t part of the study, said it shows that satellite data of ground changes provide good ways to complement what’s measured on the ground.

The quakes have stopped, but Ellsworth said, “the area was shaken pretty thoroughly over a period of about 18 months.”

And that’s a lesson that other areas — such as Kansas and Oklahoma — also have learned.