Work

Asperity‐Driven Cascading Rupture of a Mw 1.6 Induced Microearthquake

Year: 2026

Type: article

Abstract: Studies of small earthquake (M < 2) rupture processes traditionally rely on simplified models that assume symmetric slip or point sources. Using an exceptionally dense seismic network and empirical Green's function (EGF) analysis, we investigate the complex rupture of a Mw 1.6 microearthquake induced by hydraulic fracturing. Kinematic imaging via isochrone back‐projection resolves two distinct subevents occurring approximately 10 milliseconds apart, producing strong apparent rupture directivity. To test the physical mechanism driving this interaction, we perform dynamic rupture simulations constrained by these observations. We demonstrate that the failure of a primary asperity dynamically triggers a neighboring asperity via transient stress perturbations. This asperity‐driven cascading mechanism effectively explains the observed multi‐stage moment release and the apparent supershear rupture velocity (∼3.7 km/s). Our findings provide direct evidence that interacting fault asperities govern microseismic behavior. Such complexity challenges simple source assumptions and is essential for accurately assessing seismic hazards in human‐induced environments.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl117977

Authors: Xinxing Chen, Haichao Chen, Fenglin Niu, Xiaobo Meng

Institutions: China University of Petroleum, Beijing, University of Science and Technology of China, Chengdu University of Technology

Language: English

Topic: earthquake and tectonic studies

Subfield: Geophysics

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,190

OpenAlex ID: W7155621092

FWCI: 3.914

Cites: 32

Cited by: 1

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