Edge-computed Shaking Intensity Parameters: Application to the Community Seismic Network (CSN)

Monica D. Kohler, Richard Guy, Eliseo Banda, Robert W. Clayton, Ellen Yu, & Allen L. Husker

Submitted September 7, 2025, SCEC Contribution #14522, 2025 SCEC Annual Meeting Poster #TBD

The Community Seismic Network (CSN) continues to expand in southern and northern California and consists of over 1200 permanent 3-component accelerometers that report in near-real-time to the Amazon cloud. We present findings from two new developments: 1) testing of several fast, real-time, recursive algorithms to compute spectral accelerations for implementation in the seismic station software; and 2) preliminary findings from a recent deployment of 75 sensors at the 10-story cold-formed steel building that was constructed and tested at the large, outdoor NHERI@UCSD shaketable during June 2025.

Real-time Spectral Accelerations (SAs): We present comparisons of efficiency and accuracy of four recursive algorithms that solve the SDOF differential equation in real time to compute SAs in-situ at individual sensor sites, i.e. at the edge. Each CSN station is a low-cost sensor coupled to a micro-computer (Raspberry Pi) that is connected to the Internet. All shaking intensity parameters computed at the CSN sensor site (PGA, PGV, SAs) are formatted into ShakeMap message packets and transmitted to an AQMS import server. Once it receives notification of an earthquake, ShakeMap queries the AQMS database for any CISN and CSN amplitudes associated with that event to create ShakeMaps. ShakeMaps for recent southern California earthquakes indicate an order of magnitude improvement in spatial resolution when the high-density CSN data are added.

10-story steel building structural health monitoring: CSN data recorded at the 10-story cold-formed steel building at the NHERI@UCSD shaketable present a real-world test of the structural health monitoring capabilities of the CSN hardware and software architecture that carries out continuous recording. In June 2025, over 15 large-amplitude shake tests using scaled earthquake ground motion inputs were conducted at the 10-story on the shaketable. At least three tests were large enough to produce a significant amount of damage to the building. Preliminary findings of frequency domain response observations from the shake tests show a permanent reduction of ~15% in the fundamental, first, and second overtones of the building’s resonant frequencies that are likely the result of shaking-induced damage inside the building.

Citation
Kohler, M. D., Guy, R., Banda, E., Clayton, R. W., Yu, E., & Husker, A. L. (2025, 09). Edge-computed Shaking Intensity Parameters: Application to the Community Seismic Network (CSN). Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Ground Motions (GM)