Assessing the effectiveness of the shear-tensile-compr essi ve model in earthquake source inversions: synthetic experiments and field application

0583510 - GFÚ 2025 RIV GB eng J - Journal Article
Ren, Y. - Vavryčuk, Václav - Zhao, L.
Assessing the effectiveness of the shear-tensile-compr essi ve model in earthquake source inversions: synthetic experiments and field application.
Geophysical Journal International. Roč. 236, č. 1 (2024), s. 161-173. ISSN 0956-540X. E-ISSN 1365-246X
Institutional support: RVO:67985530
Keywords : seismicity and tectonics * earthquake observations * theoretical seismology
OECD category: Volcanology
Impact factor: 2.8, year: 2022

As an alternative to the moment tensor (MT) model for earthquake sources, the shear-tensile- compressi ve (STC) model of fers a kinematic description of the source mechanism and leads to a more robust inversion problem. However, the premise of the source inversion based on STC is to ensure the accuracy of parameter
κdefined as the ratio of the Lam ´e constants, κ= λ/μ, in a fault zone. In this study, we carry out a series of synthetic experiments using P -wave amplitudes in source mechanism inversions based on both the STC and MT models, and consider the influence of noise, the uncertainties in source locations and in the velocity model. We show that the nonlinear STC inversion with an appropriate value of κleads to more accurate result compared to the linear MT inversion. We also propose a new joint-STC inversion method to jointly invert for parameter κand the remaining parameters of the STC model (magnitude and the strik e, dip, rak e and slope angles). The results indicate that our proposed method yields robust results for both the parameter κand focal mechanisms. We apply our joint-STC inversion method to field microearthquake data observed in the West Bohemia region to validate some of the conclusions drawn from the synthetic experiments.
Permanent Link: https://hdl.handle.net/11104/0351483