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Abstract The 2023 Turkey earthquake sequence involved unexpected ruptures across numerous fault segments. We present 3D dynamic rupture simulations to illuminate the complex dynamics of the earthquake doublet. Our models are constrained by observations available within days of the sequence and deliver timely, mechanically consistent explanations of the unforeseen rupture paths, diverse rupture speeds, multiple slip episodes, heterogeneous fault offsets, locally strong shaking, and fault system interactions. Our simulations link both earthquakes, matching geodetic and seismic observations and reconciling regional seismotectonics, rupture dynamics, and ground motions of a fault system represented by 10 curved dipping segments and embedded in a heterogeneous stress field. The Mw 7.8 earthquake features delayed backward branching from a steeply branching splay fault, not requiring supershear speeds. The asymmetrical dynamics of the distinct, bilateral Mw 7.7 earthquake are explained by heterogeneous fault strength, prestress orientation, fracture energy, and static stress changes from the previous earthquake. Our models explain the northward deviation of its eastern rupture and the minimal slip observed on the Sürgü fault. 3D dynamic rupture scenarios can elucidate unexpected observations shortly after major earthquakes, providing timely insights for data-driven analysis and hazard assessment toward a comprehensive, physically consistent understanding of the mechanics of multifault systems.
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This content will become publicly available on May 16, 2026
The big impact of small quakes on tectonic tremor synchronization
Tectonic tremor tracks the repeated slow rupture of certain major plate boundary faults. One of the most perplexing aspects about tremor is that some fault segments produce strongly periodic, spatially extensive tremor episodes, while others have more disorganized, asynchronous activity. Here, we measure the size of segments that activate synchronously during tremor episodes and the relationship to regional earthquake rate on major plate boundaries. Tremor synchronization in space seems to be limited by the activity of small, nearby crustal and intraslab earthquakes. This observation can be explained by a competition between the self-synchronization of fault segments and perturbation by regional earthquakes. Our results imply previously unrecognized interactions across subduction systems, in which earthquake activity far from the fault influences whether it breaks in small or large segments.
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- Award ID(s):
- 2031457
- PAR ID:
- 10638698
- Publisher / Repository:
- AAAS
- Date Published:
- Journal Name:
- Science Advances
- Volume:
- 11
- Issue:
- 20
- ISSN:
- 2375-2548
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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