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The 2023 Kahramanmaraş earthquake sequence produced extensive liquefaction-induced ground deformations along the infilled shoreline of the port city of İskenderun, Türkiye. Observed liquefaction effects included ground settlement, seaward lateral spreading, and failures along a rubble mound seawall lining the coast. These effects, among other factors, likely contributed to ongoing flooding in İskenderun during moderate storm and high tide events following the earthquakes. The Geotechnical Extreme Events Reconnaissance (GEER) team collected detailed observations and measurements of selected sites affected by liquefaction. This paper presents lateral spreading, ground settlement, and flooding observations in İskenderun, which suggest widespread movements of the coastline relative to the current sea level. The Doğan restaurant case history is described in detail, where earthquake ground deformations and subsequent flooding damaged a dining patio, seawall, and nearby park facilities. Insights from these observations suggest a need to better understand multi-hazard liquefaction and flood consequences to enhance the resilience of coastal cities.
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Liquefaction ground deformations and cascading coastal flood hazard in the 2023 Kahramanmaraş earthquake sequence
The 2023 Kahramanmaraş earthquake sequence produced extensive liquefaction-induced ground deformations and ongoing flooding along the shoreline of the Mediterranean port city of İskenderun, Türkiye. This study compiles field observations and analyses from cross-disciplinary perspectives to investigate whether earthquake-induced liquefaction was a significant factor for increasing the flood hazard in İskenderun. Geotechnical reconnaissance observations following the earthquakes included seaward lateral spreading, settlement beneath buildings, and failures of coastal infrastructure. Three presented lateral spreading case histories indicate consistent ground deformation patterns with areas of reclaimed land. Persistent scatterer interferometry (PSI) measurements from synthetic aperture radar (SAR) imagery identify a noticeably greater rate of pre- and post-earthquake subsidence within the İskenderun coastal and urban areas relative to the surrounding regions. The PSI measurements also indicate subsidence rates accelerated following the earthquakes and were typically highest near the observed liquefaction manifestations. These evaluations suggest that while the liquefaction of coastal reclaimed fill caused significant ground deformations in the shoreline area, ongoing subsidence of İskenderun and other factors likely also exacerbated the flood hazard. Insights from this work suggest the importance of evaluating multi-hazard liquefaction and flood consequences for enhancing the resilience of coastal cities.
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- Award ID(s):
- 2338026
- PAR ID:
- 10506354
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Earthquake Spectra
- Volume:
- 40
- Issue:
- 3
- ISSN:
- 8755-2930
- Format(s):
- Medium: X Size: p. 1845-1869
- Size(s):
- p. 1845-1869
- Sponsoring Org:
- National Science Foundation
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