Nodal Seismometer Recordings of Aftershocks of the 5 December 2024 M 7.0 Offshore Cape Mendocino, California Earthquake

At 10:44:21 local time on December 5, 2024, a M 7.0 earthquake occurred approximately 70 km southwest of Ferndale, California, just west of the Mendocino Triple Junction. Starting the next day, the U.S. Geological Survey deployed nodal seismometers (nodes) in the Eel River Valley, near Cape Mendocino, and along the California Highway 101 corridor to compliment local permanent stations of the Northern California Seismic Network (NCSN). The USGS deployed a total of 114 nodal stations, each consisting of a SmartSolo IGU-16HR 3-component nodal seismometer that recorded continuously at a 500-Hz sampling rate and was time-corrected using GPS. The nodal stations, combined with the permanent network, provided more densely spaced recordings of events in the region, with the combined network recording 295 M 2.5+ aftershocks in the following ~ five weeks. Fourteen of the aftershocks were greater than M 4.0, as determined by the NCSN (https://ncedc.org/ncsn). The combined dense nodal and permanent network stations are expected to make it possible to significantly increase the number of events in, and the accuracy of, the current earthquake catalog for the region during the deployment period of approximately December 06 through January 16, 2025.