Strong-Motion Records of the M6.4 Ferndale Earthquake on 20 December 2022 and Its Aftershocks
Description:
The M6.4 Ferndale, California earthquake on December 20, 2022, and its aftershocks generated valuable strong-motion data sets at several California Integrated Seismic Network stations of CSMIP, NSMP, NCSN and BDSN regional seismic networks. The epicenter of the mainshock was located offshore, 15 km southwest of Ferndale, at a focal depth of about 18 km. The largest ground acceleration of 1.46g was recorded at the CSMIP station Rio Dell – 101/Painter St Overpass Grounds, located about 27 km northeast of the epicenter. The closest ground station to the epicenter was the NCSN-KCT Station in Cape Town that recorded 0.12g. The maximum ground displacement of 14 cm was calculated using the strong motion record from the BDSN station DMOR in Dinsmore located about 64 km from the epicenter. Stronger ground shaking was observed in the east and northeast of the epicenter. Spatial variation of ground acceleration fits well with the ground motion predictions when the finite fault model is taken into consideration for the earthquake.
A M5.3 aftershock occurred on January 1, 2023. The aftershock was located onshore at about 15 km southeast of Rio Dell, at a deeper depth of 30km. It generated strong shaking in the area. The Rio Dell – 101/Painter St Overpass Grounds station recorded 0.70g acceleration at about 15 km from the epicenter. Also, the mainshock and some aftershocks were recorded at the CSMIP and NSMP structural stations in the area. The M6.4 and M5.3 earthquakes generated the largest structural acceleration at two bridges in Rio Dell area with recorded accelerations over 2 g. The strong-motion records for the mainshock (>160 records) and some aftershocks are available for view and download at the Center for Engineering Strong Motion Data (CESMD) (strongmotioncenter.org), a jointly operated center of the California and United States Geological Surveys.
Session: New Observations and Modeling of Triggered Seismicity [Poster]
Type: Poster
Date: 4/19/2023
Presentation Time: 08:00 AM (local time)
Presenting Author: Hamid Haddadi
Student Presenter: No
Invited Presentation:
Authors
Hamid Haddadi Presenting Author Corresponding Author hamid.haddadi@conservation.ca.gov California Geological Survey |
Lijam Hagos lijam.hagos@conservation.ca.gov California Geological Survey |
Lisa Schleicher lschleicher@usgs.gov U.S. Geological Survey |
Mahesh Dhar mahesh.dhar@conservation.ca.gov California Geological Survey |
Jamison Steidl steidl@ucb.edu University of California, Santa Barbara |
Lind Gee lgee@usgs.gov U.S. Geological Survey |
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Strong-Motion Records of the M6.4 Ferndale Earthquake on 20 December 2022 and Its Aftershocks
Category
New Observations and Modeling of Triggered Seismicity