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Earthquake rupture arrest from depth‐dependent frictional stability on the Pütürge segment of the East Anatolian Fault Zone, Türkiye (Turkey)

Johanna Nevitt·Tamara Nicole Jeppson·Roger Bilham·Diane E. Moore·David A. Lockner·William D Barnhart·Ziyadin Cakir·Efe Ayruk·Benjamin A. Brooks·Dawn Catherine Sweeney Ruth·Nima Ekhtari·Francisco Gomez·Jonathan Weiss·Sarah E. Minson·Semih Ergintav·Ugur Dogan·Seda Ozarpaci·Nadine G. Reitman·Ruth A. Harris
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Abstract

Determining why earthquake ruptures stop is a central challenge in earthquake science and seismic hazard assessment. The Pütürge segment of the East Anatolian Fault Zone, Türkiye, exhibits shallow creep (<∼3 km depth) yet hosts M > 6.5 earthquake ruptures at greater depth. Here, we evaluate whether variations in frictional stability along this segment aided arrest of the 2020 M 6.7 Elaziğ and 2023 M 7.8 Pazarcık earthquake ruptures. Analysis of Sentinel‐1 Synthetic Aperture Radar imagery indicates the 2023 M 7.8 rupture propagated laterally into a metamorphic massif within the Pütürge segment, where slip rapidly decayed below detection limits. Creepmeters along this segment recorded no significant surface afterslip (<3 mm) in the following year. To investigate this fault‐slip behavior, we conducted triaxial friction experiments on Pütürge fault gouge sampled from an outcrop exposure. The gouge, composed primarily of muscovite, quartz, and calcite, is velocity strengthening at conditions approximating 0–2.5 km depth and velocity weakening at 4–5 km depth. This transition to velocity‐weakening friction is associated with enhanced comminution and shear localization observed microstructurally. Our results suggest that depth‐dependent frictional stability of the Pütürge fault segment facilitates rupture nucleation and propagation at depth while maintaining rupture‐arresting behavior near Earth’s surface.

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The Seismic RecordArticle
90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 35.4220709° to 38.80359745310301° latitude; 35.6210835° to 39.913940827255146° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Johanna Nevitt, Tamara Nicole Jeppson, Roger Bilham, Diane E. Moore, David A. Lockner, William D Barnhart, Ziyadin Cakir, Efe Ayruk, Benjamin A. Brooks, Dawn Catherine Sweeney Ruth, Nima Ekhtari, Francisco Gomez, Jonathan Weiss, Sarah E. Minson, Semih Ergintav, Ugur Dogan, Seda Ozarpaci, Nadine G. Reitman, Ruth A. Harris. 2026-03-19. Earthquake rupture arrest from depth‐dependent frictional stability on the Pütürge segment of the East Anatolian Fault Zone, Türkiye (Turkey). https://doi.org/10.1785/0320250054

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Article subjectPütürge segment of the East Anatolian Fault Zone placeThe Seismic Record subjectTurkey place

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