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Data Sets for 2025 Malibu Nodal Deployment
This page provides information about seismic data collected by two nodal seismic arrays installed near Malibu, California. The two arrays included a total of 58 three-component SmartSolo nodes installed for one month from March 21-April 22, 2025. The goal of the deployment was to capture, in higher resolution, ongoing seismicity from two nearby earthquake clusters that had been active for over a year.
Background on the seismicity: From 2024 to 2025, two active earthquake clusters separated by less than 10 km occurred near Malibu, California (Figure 1). The western earthquake cluster started on February 9th, 2024, with a M4.6 earthquake. The event’s moment tensor indicted an East-West striking normal fault. Seismic activity in a ~2 km radius around the M4.6 event continued through May 2024. On September 12th, a M4.7 earthquake occurred approximately 10 km east of the earlier M4.6 event, starting a new cluster of activity. The moment tensor solution indicated this event occurred on a NW or NE oriented strike-slip or oblique slip fault. Activity continued in the eastern cluster through 27 January 2025. On February 14th and 15th, 2025, activity started up again within the western cluster with two M3.7 earthquakes, the third M4+ event in the sequence (M4.1) on March 9th, 2025, and a M3.9 earthquake on March 16th, 2025. Given the continued seismic activity in the Malibu area, a nodal deployment on March 21st, 2025.
Background on the arrays: Two nodal arrays were deployed at
distances of 6-16 km from the two seismicity clusters. Array 1 was located 6 km
west of the western earthquake cluster and 16 km west of the eastern earthquake
cluster (Figure 1). This array had a total of 34 sensors installed in 6 lines
each with 5-6 sensors separated by approximately 10 m (Figure 2A). The array was
located on a steep hillside near SCSN station CI.CHK. This is a very quiet site
with few local sources of anthropogenic noise. Array 2 was located 6 km
northwest of the eastern earthquake cluster and 10 km northeast of the western
earthquake cluster. The array had a total of 24 sensors installed in 6 lines,
each with 6 sensors separated by approximately 10 m (Figure 2B). The array was
located on gently sloping site on a working vineyard, but away from major roads
or other noise sources. Unfortunately, approximately 1/3 of the sensors were
disturbed (removed from the ground) before the end of the experiment. All
sensors were partially buried with the top of the sensor at ground level to
allow for easy retrieval.
Project Leads: Elizabeth Cochran (USGS), Xiaozhuo Wei (Caltech), Hao Zhang (Caltech), Zhongwen Zhan (Caltech) Field Team: Elizabeth Cochran (USGS), J. Ole Kaven (USGS), Devin McPhillips (USGS), Eitan Rapaport (Caltech), Alexis Saez Uribe (Caltech), Katherine Scharer (USGS), Dominic Sheckel (Caltech), Sarah Stamps (VT), Xiaozhuo Wei (Caltech), Hao Zhang (Caltech) Contact information: ecochran at usgs.gov
Please also acknowledge the DOIs for SCSN and SCEDC as described in the Acknowledgements section.
Files
All files can be used from the SCEDC AWS Open Dataset. See the SCEDC Cloud page for more information about working with the cloud archive.
- waveform files (in sac): s3://scedc-pds/Malibu-Nodal
- metadata files (in FDSN StationXML): s3://scedc-pds/Malibu-Nodal/metadata
Acknowledgements
Data and materials availability: Waveform files and metadata are publicly available from the Southern California Earthquake Data Center (scedc.caltech.edu) doi:10.7909/C3WD3xH1. All remaining data are available in the main text or the supplementary materials.
