Earthquakes Induced by Fluid Injection
No. Of more than 150,000 Class II injection wells in the United States, roughly 40,000 are waste fluid disposal wells for oil and gas operations.
Is it possible to anticipate whether a planned wastewater disposal activity will trigger earthquakes that are large enough to be of concern?
Currently, there are no methods available to do this.
Earth's crust is pervasively fractured at depth by faults.
The largest earthquake induced by fluid injection that has been documented in the scientific literature was the November 6, 2011 earthquake in central Oklahoma. It had a magnitude of 5.6. Earlier that year, a magnitude 5.3 earthquake was induced by f
Are earthquakes induced by fluid-injection activities always located close to the point of injection?
No. Given enough time, the pressure increase created by injection can migrate substantial horizontal and vertical distances from the injection location. Induced earthquakes commonly occur several kilometers below the injection point.
Is there any possibility that a wastewater injection activity could interact with a nearby fault to trigger a major earthquake that causes extensive damage over a broad region?
So far, there is no conclusive example linking injection operations to triggering of major earthquakes, however we cannot eliminate this possibility.
Does the production of natural gas from shales cause earthquakes? If so, how are the earthquakes related to these operations?
To produce natural gas from shale formations, it is necessary to increase the interconnectedness of the pore space (permeability) of the shale so that the gas can flow through the rock mass and be extracted through production wells.
USGS supports both internal and external (university-based) research on the causes of induced earthquakes.
In a few cases, yes, but in most cases no. The majority of the earthquakes in Oklahoma since 2011 occur in areas where oil is being produced by pumping massive volumes of water out of naturally fractured formations to extract much smaller volumes of o