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2023 U.S. 50-State National Seismic Hazard Model

Description: 

We are developing the 2023 U.S. National Seismic Hazard Model for all 50 states by applying new seismicity, fault rupture models, and ground motion assessments. We consider two types of models: (1) a public model that guides hazard assessments intended for building code provisions and policy applications and (2) a research model geared towards less formal applications that may be included in future public models. New data and methods will be introduced in the 2023 earthquake source components: earthquake catalogs - excluding induced earthquakes, alternative declustering methods, spatially smoothed seismicity, new geodetic- and geologic-based fault and deformation models, and earthquake rupture forecast models accounting for a more complete representation of potential earthquakes in Alaska, Hawaii, and the conterminous U.S. Improved ground motion models (GMMs) consider new NGA-Subduction, modified NGA-East and NGA-West2. Some GMMs and earthquake source models contain changes in median and aleatory variability that need to be evaluated and weighted. Amplification models will also consider available 3D simulations to supplement the empirical GMMs, and basin specific data in California Central Valley, Seattle Washington, Los Angeles California, and near Portland Oregon. New stress drop, tomographic, and other geophysical models help refine the complex boundary between the tectonically stable and active regions used in assigning GMMs. The research model may incorporate more geological information on timing of past earthquakes for time-dependent assessments and on regional variations in earthquake shaking - accounted for by a partially non-ergodic ground motion representation. Scenarios and population exposure assessments of these models will help users assess impacts of the earthquakes and facilitate risk mitigation measures.

Session: USGS National Seismic Hazard Models: 2023 and Beyond

Type: Oral

Date: 4/18/2023

Presentation Time: 08:00 AM (local time)

Presenting Author: Mark D. Petersen

Student Presenter: No

Invited Presentation: 

Authors