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Session: U.S. Geological Survey National Seismic Hazard Model Components

Type: Oral

Date: 4/24/2019

Time: 08:30 AM

Room: Pike

During 2017-2018, the National Seismic Hazard Model was updated by incorporating (1) new median ground motion models, new estimates of their epistemic uncertainties and aleatory variabilities, and new soil amplification factors for the central and eastern U.S., (2) amplification of long-period ground motions in deep sedimentary basins in the Los Angeles, San Francisco, Seattle, and Salt Lake City areas, (3) an updated seismicity catalog, which includes new earthquakes that occurred between 2012 and 2017, and (4) improved computer code and implementation details. Results show significantly increased ground shaking in many (but not all) locations across the central and eastern U.S., including the four urban areas (listed above) that overlie deep sedimentary basins in the western U.S. These maps are being considered by the Building Seismic Safety Council for inclusion in upcoming building codes. Due to population growth, more people live and work in areas of high or moderate seismic hazard than ever before, leading to higher risk of undesirable consequences from future ground shaking.

Presenting Author: Peter Powers

Additional Authors

Mark D Petersen

Corresponding Author

mpetersen@usgs.gov

U.S. Geological Survey, Denver, Colorado, United States

Allison M Shumway

ashumway@usgs.gov