Assessing tomographic capabilities of distributed acoustic sensing data near the Mendocino Triple Junction

Ettore Biondi, James W. Atterholt, Eli Bird, Jeff J. McGuire, & Andrew J. Barbour

Submitted September 7, 2025, SCEC Contribution #14663, 2025 SCEC Annual Meeting Poster #TBD

In recent years, distributed acoustic sensing (DAS) has emerged as an effective tool for seismological applications, with its use rapidly expanding. The global growth of fiber infrastructure provides an ideal framework for enhancing continuous seismic monitoring by integrating DAS into existing seismic networks. Despite the challenges posed by the vast data volumes generated by DAS (terabytes per day), modern computational architectures, such as general-purpose graphics processing units, and novel methodologies like machine-learning algorithms, allow for efficient processing and analysis of these datasets. DAS has already proven useful for earthquake monitoring, rupture imaging, and subsurface characterization.
Building on this, we test the resolution achievable using the United States Geological Survey (USGS) DAS array deployed within the Mendocino Triple Junction (MTJ) in 2022 by applying an adjoint-state Eikonal tomography method. This approach combines traveltime picks from body waves, obtained using the PhaseNet-DAS algorithm, and surface-wave traveltimes derived from noise cross-correlation. The MTJ region, a complex tectonic setting where the Gorda, North American, and Pacific plates converge, is currently monitored by the USGS DAS array, which provides high spatial density data for seismic analysis. By leveraging these DAS data and integrating them with existing seismic catalog information, we aim to generate high-resolution subsurface images and improve earthquake location accuracy in this region. The high-resolution tomographic images from this DAS array could enhance our understanding of the subsurface structures in the MTJ and further demonstrate the potential of DAS arrays for detailed seismic imaging and earthquake monitoring.

Key Words
DAS, tomography, Mendocino Triple Junction

Citation
Biondi, E., Atterholt, J. W., Bird, E., McGuire, J. J., & Barbour, A. J. (2025, 09). Assessing tomographic capabilities of distributed acoustic sensing data near the Mendocino Triple Junction. Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Community Earth Models (CEM)