Near-field coseismic deformation across the Sürgü–Erkenek segments revealed by integrated GNSS and InSAR analysis following the 2023 Kahramanmaraş Earthquakes, Türkiye
Journal of Earth System Science, cilt.135, sa.3, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 135 Sayı: 3
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s12040-026-02927-9
- Dergi Adı: Journal of Earth System Science
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Environment Index, Geobase, Zoological Record, Academic Search Ultimate (EBSCO), Natural Science Collection (ProQuest), Biomedical Reference Collection: Corporate Edition (EBSCO), Earth, Atmospheric, & Aquatic Science Collection (ProQuest), Engineering Source (EBSCO)
- Anahtar Kelimeler: Coseismic deformation, East Anatolian Fault Zone, GNSS, Kahramanmaraş earthquakes, SAR pixel offset tracking, Sürgü Segment, torsional deformation
- Sivas Cumhuriyet Üniversitesi Adresli: Evet
Özet
Abstract: The two successive large earthquakes (Mw 7.7 and Mw 7.6) that struck along the East Anatolian Fault Zone (EAFZ) on 6 February 2023, broke a long-lasting seismic quiescence in the region and produced a surface rupture exceeding 500 kilometres. These earthquakes triggered a devastating series of events that resulted in extensive structural damage and significant loss of life, underscoring the critical importance of reassessing the region’s seismogenic potential and the associated changes in environmental stress. This study focuses on the coseismic and near-field deformation of the Erkenek (ES) and Sürgü segments (SS), where a dense GNSS network – supplemented by SAR-based pixel offset tracking – captures deformation patterns using previously unpublished GNSS stations situated between the two main shocks. The results of this study reveal heterogeneous displacement patterns and opposing directional motions between ES and SS, indicating torsional deformation along the Sürgü Segment – a fault that remained unruptured by the doublet but exhibits elevated Coulomb stress. This torsional mechanism is significant as it highlights the development of localised strain concentration zones that may influence future rupture propagation paths. Such strain localisation may modify stress transfer patterns between adjacent fault segments and therefore has important implications for segment interaction and seismic hazard assessment. The epicentres and focal mechanism solutions of these destructive strike–slip earthquakes, together with the observed displacement patterns, indicate the presence of a localised shear zone between the Erkenek and Sürgü segments, where differential left-lateral motion of adjacent fault blocks produced large and spatially variable displacements along the Sürgü segment. These findings, when integrated with kernel density-based aftershock distributions, Coulomb stress transfer analyses, and b-value variations consistently indicate elevated post-seismic stress along the unruptured Sürgü Segment. These observations collectively demonstrate that the SS remains a critical locus of strain accumulation and should be considered a priority in future seismic hazard assessments. Research highlights: Near-field coseismic deformation across the Sürgü–Erkenek segments is resolved using integrated GNSS and InSAR data. Opposite-sense coseismic displacements of ~3–4 m are identified on the unruptured Sürgü segment. Results reveal significant strain transfer and complex deformation patterns along the East Anatolian Fault.