Earthquake Geology Inputs for the 2025 Update of the Puerto Rico-U.S. Virgin Islands Portion of the National Seismic Hazard Model
Description:
Two decades have passed since the 2003 United States Geological Survey National Seismic Hazard Model (NSHM) for Puerto Rico and the U.S. Virgin Islands (PRVI). In advance of the 2025 PRVI NSHM update, we developed 3 databases to summarize and characterize new onshore and offshore fault source information, excluding the subduction zone, in the region between 62° to 70° W and 16° to 21° N. These include (1) fault section, (2) fault-zone polygon, and (3) earthquake geology (fault slip rate, earthquake recurrence interval) databases, which represent updates to fault parameters used in prior seismic hazard models. We revised and added fault sources from studies published since 2003 that document improvements to fault locations, geometries, or activities. New fault sources meet the criteria of a length ≥7 km, evidence of recurrent tectonic Quaternary activity, and documentation in a peer-reviewed source. While the 2003 NSHM included only 3 fault sections and 2 fault-zone polygons (areal sources), the 2025 draft databases, which will soon be subject to community input, include 24 new faults and up to 5 fault-zone polygons, including revisions to the Mona and Anegada extensional zone areal sources. To characterize activity rates on faults without published slip rates, we assigned slip rate bins to faults based on landscape expression and published paleoseismic trench observations. At least 12 fault sources were evaluated but not included in the revised databases due to a lack of published information or equivocal information about fault location, geometry, or recurrent Quaternary activity. The new databases will serve as inputs to the deformation models during upcoming model implementation.
Session: 2025 Puerto Rico and the U.S. Virgin Islands National Seismic Hazard Model Update
Type: Oral
Date: 4/18/2023
Presentation Time: 04:45 PM (local time)
Presenting Author: Jessica A. T. Jobe
Student Presenter: No
Invited Presentation:
Authors
Jessica Jobe Presenting Author Corresponding Author jjobe@usgs.gov U.S. Geological Survey |
Richard Briggs rbriggs@usgs.gov U.S. Geological Survey |
Uri ten Brink utenbrink@usgs.gov U.S. Geological Survey |
Thomas Pratt tpratt@usgs.gov U.S. Geological Survey |
K. Stephen Hughes kenneth.hughes@upr.edu University of Puerto Rico, Mayagüez |
Alexandra Hatem ahatem@usgs.gov U.S. Geological Survey |
Christopher DuRoss cduross@usgs.gov U.S. Geological Survey |
Nadine Reitman nreitman@usgs.gov U.S. Geological Survey |
Julie Herrick jherrick@usgs.gov U.S. Geological Survey |
Camille M Collett ccollett@usgs.gov U.S. Geological Survey, Golden, Colorado, United States |
Sylvia Nicovich snicovich@usgs.gov U.S. Geological Survey, Golden, Colorado, United States |
Katherine Scharer kscharer@usgs.gov U.S. Geological Survey, Pasadena, California, United States |
Stephen DeLong sdelong@usgs.gov U.S. Geological Survey, Moffett Field, California, United States |
Earthquake Geology Inputs for the 2025 Update of the Puerto Rico-U.S. Virgin Islands Portion of the National Seismic Hazard Model
Category
2025 Puerto Rico and the U.S. Virgin Islands National Seismic Hazard Model Update