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

The Seismic Record
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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.

Suggested Citation

Nevitt, J., Jeppson, T.N., Bilham, R., Moore, D.E., Lockner, D., Barnhart, W.D., Cakir, Z., Ayruk, E., Brooks, B.A., Ruth, D.C., Ekhtari, N., Gomez, F., Weiss, J., Minson, S.E., Ergintav, S., Dogan, U., Ozarpaci, S., Reitman, N.G., and Harris, R.A., 2026, Earthquake rupture arrest from depth‐dependent frictional stability on the Pütürge segment of the East Anatolian Fault Zone, Türkiye (Turkey): The Seismic Record, v. 6, no. 1, p. 106-116, https://doi.org/10.1785/0320250054.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Earthquake rupture arrest from depth‐dependent frictional stability on the Pütürge segment of the East Anatolian Fault Zone, Türkiye (Turkey)
Series title The Seismic Record
DOI 10.1785/0320250054
Volume 6
Issue 1
Publication Date March 19, 2026
Year Published 2026
Language English
Publisher Seismological Society of America
Contributing office(s) Earthquake Science Center
Description 11 p.
First page 106
Last page 116
Country Turkey
Other Geospatial Pütürge segment of the East Anatolian Fault Zone
Additional publication details