고분해능 시추공 변형률계 활용을 통한 지진 연구 가능성 = A Feasibility Study of Earthquake Monitoring Using a High-resolution Borehole Strainmeter

다국어 초록 (Multilingual Abstract)

This work investigates whether stress changes induced by an earthquake can be estimated using the deformation measured by high-resolution borehole strainmeters. We estimate the changes in the orientation and magnitude of the principal compression stresses using borehole strainmeter data recorded before and after the M7.2 El Mayor-Cucapah earthquake on April 4, 2010. Clear differences in the stress orientations and magnitudes are apparent before and after the event. The change in stress orientation appears related to subtle increases of stress in the tectonic maximum principal orientation, which is in agreement with the earthquake focal mechanism solution. The sudden stress drop at the onset of the earthquake was 10-3-10-2 MPa in the principal orientations. The Coulomb stress transfer model, which can estimate stress transfer, predicts a shear stress increase of (0.1-0.6) × 10-2 MPa at the strainmeter site, which is in line with the measured data (0.3-0.8) × 10-2 MPa. Overall, our results suggest that borehole strainmeter data reflect the subtle stress changes associated with earthquake occurrence, and that such data can be utilized for earthquake-related research.

참고문헌 (Reference)

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