Non‐Typical Supershear Rupture: Fault Heterogeneity and Segmentation Govern Unilateral Supershear and Cascading Multi‐Fault Rupture in the 2021 Mw ${M}_{w}$7.4 Maduo Earthquake
Abstract Previous geodetic and teleseismic observations of the 2021 7.4 Maduo earthquake imply surprising but difficult‐to‐constrain complexity, including rupture across multiple fault segments and supershear rupture. Here, we present an integrated analysis of multi‐fault 3D dynamic rupture models, high‐resolution optical correlation analysis, and joint optical‐InSAR slip inversion. Our preferred model, validated by the teleseismic multi‐peak moment rate release, includes unilateral eastward double‐onset supershear speeds and cascading rupture dynamically triggering two adjacent fault branches. We propose that pronounced along‐strike variation in fracture energy, complex fault geometries, and multi‐scale variable prestress drives this event's complex rupture dynamics. We illustrate how supershear transition has signatures in modeled and observed off‐fault deformation. Our study opens new avenues to combine observations and models to better understand complex earthquake dynamics, including local and potentially repeating supershear episodes across immature faults or under heterogeneous stress and strength conditions, which are potentially not unusual.
Authors
- Alice‐Agnes Gabriel (ORCID: https://orcid.org/0000-0003-0112-8412)
- Léa Pousse‐Beltran (ORCID: https://orcid.org/0000-0003-2833-411X)
- James Hollingsworth (ORCID: https://orcid.org/0000-0003-0122-296X)
- Mathilde Marchandon (ORCID: https://orcid.org/0000-0001-7883-8397)
- Jorge N. Hayek (ORCID: https://orcid.org/0000-0002-0351-3368)
- Duo Li (ORCID: https://orcid.org/0000-0002-8641-337X)
- Tao Li (ORCID: https://orcid.org/0000-0002-3563-8245)
Institutions
- GNS Science (NZ)
- Centre National de la Recherche Scientifique (FR)
- Scripps Institution of Oceanography (US)
- University of California San Diego (US)
- Institut des Sciences de la Terre (FR)
- Xinjiang Entry-Exit Inspection and Quarantine Bureau (CN)
- Université Gustave Eiffel (FR)
- Institut de Recherche pour le Développement (FR)
- Institute of Geology, China Earthquake Administration
- Université Savoie Mont Blanc (FR)
- Ludwig-Maximilians-Universität München (DE)
- Université Grenoble Alpes (FR)
- China Earthquake Administration (CN)
Publication Details
- Journal
- Geophysical Research Letters
- Published
- 2024-10-14
- DOI
- https://doi.org/10.1029/2024gl110128
- Citations
- 8
- Primary Topic
- earthquake and tectonic studies
- Type
- article
- Field-Weighted Citation Impact
- 4.28
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- European Space Agency
- European Commission
- Agence Nationale de la Recherche
- Centre National d’Etudes Spatiales
- Directorate for Geosciences
- HORIZON EUROPE Framework Programme