Seismic Geodesy with Distributed Acoustic Sensing: Static Deformation from Aftershocks of the 2024 Mw 7.2 Hualien Earthquake
Yang Ma, Lingsen Meng, & Yen-Yu LinSubmitted August 30, 2026, SCEC Contribution #15168, 2026 SCEC Annual Meeting Poster #TBD
Seismic geodesy has traditionally relied on Global Navigation Satellite System (GNSS) measurements to resolve coseismic deformation and constrain earthquake source processes. However, the spatial density and sensitivity of geodetic observations remain limited by the distribution of permanent stations. Distributed Acoustic Sensing (DAS) provides a new opportunity for seismic geodesy by transforming existing fiber-optic cables into dense arrays of strain sensors with meter-scale spacing.
In this study, we analyze DAS observations from fiber-optic networks in Taiwan following the 2024 Mw 7.2 Hualien earthquake. The DAS measurements reveal clear static strain changes associated with 16 aftershocks (Ml > 4.5), providing unprecedented spatial resolution of the coseismic deformation field. Compared with predictions from Okada models, the DAS-recorded strain amplitudes generally agree within approximately one order of magnitude, while capturing subtle spatial perturbations. Remarkably, at short spatial scales (~100 m), the strain field exhibits complex patterns, with even alternating extensional and compressional signals. Numerical simulations suggest that these small-scale variations cannot be explained solely by rupture behavior. They may instead result from instrument-related artifacts in the DAS system or heterogeneous local subsurface structure, the latter being consistent with highly fractured materials near the Milun Fault. We also derive an empirical relationship between local magnitude and DAS-recorded static strain, which may provide an additional constraint on earthquake source parameters.
These observations demonstrate that DAS can serve as a powerful tool for seismic geodesy, enabling high-resolution measurements of static deformation and improving constraints on earthquake source processes.
Citation
Ma, Y., Meng, L., & Lin, Y. (2026, 08). Seismic Geodesy with Distributed Acoustic Sensing: Static Deformation from Aftershocks of the 2024 Mw 7.2 Hualien Earthquake. Poster Presentation at 2026 SCEC Annual Meeting.
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Seismology
