Sensitivities of Geodetic Source Analyses to Elastic Crust Heterogeneity Constrained by Seismic Tomography for the 2017 Mw 6.5 Jiuzhaigou, China, Earthquake

A study of the 2017 Mw 6.5 Jiuzhaigou earthquake reveals that accounting for elastic crust heterogeneity significantly improves seismic source characterization and aftershock hazard assessments. Using finite-element models (FEMs) and Sentinel-1 Interferometric Synthetic Aperture Radar observations, researchers found that heterogeneous (HET) crustal models yield more accurate slip and stress estimations compared to homogeneous (HOM) half-space models. The HET solutions show two major slip asperities with magnitudes up to 0.83 meters, consistent with aftershock distribution, while the HOM model fails to capture these features. Additionally, the study identifies a low-velocity layer at ~18 km depth, which may influence seismicity and earthquake slip, providing critical insights for assessing seismic hazards in the eastern Tibetan margin.

Tung, S., Katzenstein, K., Masterlark, T., Lei, J., Wauthier, C., & Petley, D. (2019). Sensitivities of Geodetic Source Analyses to Elastic Crust Heterogeneity Constrained by Seismic Tomography for the 2017 Mw 6.5 Jiuzhaigou, China, Earthquake. Seismological Research Letters. https://doi.org/10.1785/0220180272