Preliminary documentation of coseismic ground failure triggered by the February 6, 2023 Türkiye earthquake sequence


Görüm T., Tanyas H., Karabacak F., Yılmaz A., Girgin S., Allstadt K. E., ...More

Engineering Geology, vol.327, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 327
  • Publication Date: 2023
  • Doi Number: 10.1016/j.enggeo.2023.107315
  • Journal Name: Engineering Geology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Communication Abstracts, Compendex, INSPEC, Metadex, Pollution Abstracts, DIALNET, Civil Engineering Abstracts
  • Keywords: Bedrock rotational slide, Earthquake, Landslides, Lateral spread, Rock fall, Translational slides
  • Istanbul Technical University Affiliated: Yes

Abstract

The devastating Kahramanmaraş earthquake sequence occurred on February 6, 2023. Two main events, Mw 7.8 and Mw 7.5 occurred 9 hours apart, affected 11 cities in Turkey, and subjected an area of ∼90,000 km2 to shaking levels known to trigger landslides (peak ground acceleration > 0.08 g). Extensive landsliding was expected given the hilly terrain affected by this significant ground shaking—about 15% of the topography is steeper than 20°—but was not initially apparent in early satellite imagery, mostly because of obscuring snow that fell just after the earthquakes. However, after a more detailed investigation using high-resolution satellite images, aerial photos, and a field survey, we confirmed that this earthquake sequence did, indeed, trigger numerous landslides. In this study, we present those findings and provide a preliminary characterization of the spatial distribution, general characteristics, and dominant types of landslides and hillslope deformation triggered by the earthquake sequence. We mapped 3673 coseismic landslides, mostly concentrated in the northern half of the impacted area. Rock falls are the most abundant landslide type, but bedrock rotational landslides, translational slides and lateral spreads are also numerous. Surface rupture through mountainous terrain caused several large, and in some cases fatal, landslides. Incipient landslides and ground cracks are also widespread, especially in the north. Lithology, spatial variability of ground shaking, and topographic relief appear to be the main variables controlling the spatial distribution of coseismic landslides. There are few detailed studies of earthquake-triggered landslides in arid and semi-arid regions such as this one, nor for such complex earthquake sequences. Therefore, this contribution provides valuable information for future hazard and modeling efforts in arid and semi-arid regions.