Mixing water and faults: The Challenge of Changing Patterns of Seismicity in Stable North America.

Mixing Water and Faults: The Challenge of Changing Patterns of Seismicity in Stable North America A dramatic increase in earthquake activity in the tectonically stable central and eastern U.S. has been underway since 2009. In the state of Oklahoma alone, the rate M ? 3 earthquakes in 2014 has increased to over 100 times the historic average where they are now more frequent than in California. Evidence points to this unprecedented activity to be an unintended consequence of changing practices for the production of oil and gas from low permeability formations. The anomalous earthquakes appear to be primarily linked to disposal of co-produced formation water by injection into deep, undepleted formations. In this talk, I will discuss several field investigations of induced or potentially induced earthquakes and challenges these earthquakes pose for the development of predictive models of time-dependent seismic hazard.