2017 One-Year Seismic Hazard Forecast for the Central and Eastern United States from Induced and Natural Earthquakes

We produced a one-year 2017 seismic hazard forecast for the central and eastern United States from induced and natural earthquakes that replaces the one-year 2016 forecast, and evaluated the 2016 seismic hazard forecast to improve future assessments. The 2016 forecast indicated high seismic hazard (greater than 1% probability of damaging ground shaking in 1 year) in portions of Oklahoma/Kansas, the Raton Basin (Colorado/New Mexico border), northern Texas, northern Arkansas, and the New Madrid Seismic Zone (NSMZ). During 2016, several damaging induced earthquakes occurred in Oklahoma within the highest hazard region of the 2016 forecast; all of the 15 magnitude (M) > 4 and 3 M > 5 earthquakes occurred within the highest 5%-12% per year probability-of-damage contours shown in the 2016 forecast. Outside Oklahoma a moderate earthquake with M ≥ 4 occurred near Trinidad, Colorado, but no earthquakes with magnitudes M ≥ 2.7 were observed in northern Texas or Arkansas. Several observations of damaging ground shaking levels were also recorded in the highest hazard region of Oklahoma. The 2017 hazard model applies the same methodology and input logic tree as the 2016 forecast, but with an updated earthquake catalog. The 2017 seismic rates are lower in almost all regions of induced activity due to lower rates of earthquakes in 2016 compared to 2015, which may be related to decreased wastewater injection, caused by regulatory actions or by a decrease in unconventional oil and gas production. Nevertheless, the 2017 forecasted hazard is still hundreds of times higher than hazard calculated before induced seismicity rates rapidly increased about 2008.