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The East Anatolian fault in Turkey exhibits along-strike rupture segmentation, typically resulting in earthquakes with moment magnitude (Mw) up to 7.5 that are confined to individual segments. However, on 6 February 2023, a catastrophic Mw 7.8 earthquake struck near Kahramanmaraş (southeastern Turkey), defying previous expectations by rupturing multiple segments spanning over 300 km and overcoming multiple geometric complexities. We explore the mechanics of successive single- and multi-segment ruptures using numerical models of the seismic cycle calibrated to historical earthquake records and geodetic observations of the 2023 doublet. Our model successfully reproduces the observed historical rupture segmentation and the rare occurrence of multi-segment earthquakes. The segmentation pattern is influenced by variations in long-term slip rate along strike across the kinematically complex fault network between the Arabian and Anatolian plates. Our physics-based seismic cycle simulations shed light on the long-term variability of earthquake size that shapes seismic hazards.
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This content will become publicly available on January 4, 2026
An analysis of directivity pulses using empirical data and dynamic rupture simulations of the 2023 Kahramanmaras earthquake doublet
Near-field earthquake ground motions characterized by strong velocity pulses can cause extensive damage to buildings and structures. Such pulses were identified during the Mw 7.8 and Mw 7.5 earthquake doublet of the 2023 Turkey seismic sequence, potentially contributing to the extensive damage it caused. Therefore, a better understanding and characterization of pulse properties (e.g. period and amplitude) and their underlying physical factors are crucial for earthquake-resistant design. In this study, we characterize the velocity pulses reported in observed records and synthetic waveforms generated by a three-dimensional (3D) dynamic rupture simulation of the Mw 7.8 event. We observed significant variability in the pulse properties of the observed records in near-fault regions, particularly regarding their orientations. This variability was not fully captured by the dynamic rupture simulation. Our results indicate that directivity effects are not the only factors influencing pulse characteristics in this earthquake doublet. While site effects (e.g. basin effects) may influence pulse characteristics at some stations, local heterogeneities in slip amplitude, orientations, and fault geometries can be critical in generating or influencing pulse properties in this earthquake doublet.
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- PAR ID:
- 10564785
- Publisher / Repository:
- SAGE Publications
- Date Published:
- Journal Name:
- Earthquake Spectra
- ISSN:
- 8755-2930
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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