USGS: Nearly 75% of US Could Experience A Damaging Earthquake

Nearly 75% of the U.S. could experience damaging earthquake shaking, a recent U.S. Geological Survey report shows.

A USGS-led team of more than 50 scientists and engineers in the latest USGS National Seismic Hazard Model created a color-coded map that pinpoints where damaging earthquakes are most likely to occur based on insights from seismic studies, historical geologic data and the latest data-collection technologies.

The NSHM update, which was requested by Congress, was created as a tool to help engineers and others mitigate how earthquakes affect the most vulnerable communities by showing likely earthquake locations and how much shaking they might produce.

The update identifies nearly 500 additional faults that could produce a damaging quake. The latest iteration, the first 50-state comprehensive assessment, was updated from previous versions published in 2018 (conterminous U.S.), 2007 (Alaska) and 1998 (Hawaii).

Changes in the new model show the possibility of more damaging earthquakes along the central and northeastern Atlantic Coastal corridor, including in the cities of Washington D.C., Philadelphia, New York and Boston. In addition, there is a chance for greater shaking in the seismically active regions of California and Alaska. The new model also characterizes Hawaii as having greater potential for shaking because of observations from recent volcanic eruptions and seismic unrest on the islands.

Key findings from the updated seismic hazard model include:

• Nearly 75% of the U.S. could experience potentially damaging earthquakes and intense ground shaking, putting hundreds of millions of people at risk.
• 37 U.S. states have experienced earthquakes exceeding magnitude 5 during the last 200 years, highlighting a long history of seismic activity across the country.

The model will inform the future of building and structural design, offering critical insights for architects, engineers and policymakers on how structures are planned and constructed across the U.S. The full findings of the scientific assessment were published in the journal Earthquake Spectra.