“We have a lot of evidence that certainly leads us to believe” the quake was caused by the injections, said Cochrane, a study co-author.
The evidence isn’t as complete as other smaller earthquakes that have been linked conclusively to injections of waste, such as those in Arkansas, Colorado and Nevada, said co-author Heather Savage of Columbia.
But with the quake at the “right place” at the well, the increased pressure and the other smaller quakes across the region triggered by injections, “it becomes compelling,” she said.
In a statement, the Oklahoma Geological Survey said the interpretation that best fits the data is the quake “was the result of natural causes” but needs further study. The state officials cited new 3-D seismic data, a time lag between injection and the quakes, and the orientation of the faults to say it was natural, not induced.