Earth's Free Surface Complicates Inference of Absolute Stress From Earthquake‐Induced Stress Rotations

Autor: Jeanne L. Hardebeck
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Geophysical Research Letters, Vol 51, Iss 4, Pp n/a-n/a (2024)
Druh dokumentu: article
ISSN: 1944-8007
0094-8276
DOI: 10.1029/2023GL106574
Popis: Abstract The stress redistribution from an earthquake can produce localized measurable rotations of the principal stress axes if the absolute level of differential stress in the crust is on the order of the earthquake stress drop. Two simple analytic solutions have been developed to estimate the differential stress from an observed stress rotation. However, each has assumptions that may not be accurate near Earth's free surface. I model synthetic earthquakes in an elastic half‐space, and show that the assumptions of the methods are accurate for strike‐slip earthquakes, and for deep dip‐slip earthquakes. However, they are incorrect for shallow dip‐slip earthquakes. I introduce a free surface correction for one of the methods for dip‐slip earthquakes. I revise an analysis of stress rotations due to great subduction zone earthquakes, including this correction. The results support the original conclusion of near complete stress drop for many shallow subduction zone earthquakes.
Databáze: Directory of Open Access Journals
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