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Rupture segmentation on the East Anatolian Fault controlled by slip partitioning in a structurally complex fault system

Binhao Wang, & Sylvain D. Barbot

Submitted September 10, 2023, SCEC Contribution #12806, 2023 SCEC Annual Meeting Poster #121

The East Anatolian Fault, known for its historical large earthquakes, exhibits distinctive segmentation along its strike, typically resulting in moment magnitude (Mw) up to 7.5. However, on February 6, 2023, a catastrophic Mw 7.8 earthquake struck near KahramanmaraƟ, defying previous expectations by rupturing multiple segments spanning over 300 km and overcoming various geometric complexities. Here, we explore the mechanics of successive single- and multi-segment ruptures using numerical models of the seismic cycle calibrated to paleoseismic data and geodetic observations of the 2023 mainshock-aftershock sequence. Our model successfully reproduces the observed historical rupture segmentation and elucidates the rare occurrence of multi-segment earthquakes. The segmentation pattern is controlled by variations of long-term slip-rate along strike due to slip partitioning of the relative convergence between Arabia and Anatolia across a complex fault network. Our physics-based seismic cycle simulations shed light on the long-term variability of earthquake size that shapes seismic hazards.

Key Words
rupture segmentation, earthquake gate, slip partitioning, slip rate, earthquake cycle

Citation
Wang, B., & Barbot, S. D. (2023, 09). Rupture segmentation on the East Anatolian Fault controlled by slip partitioning in a structurally complex fault system. Poster Presentation at 2023 SCEC Annual Meeting.


Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)