Türkiye Mw 7.7 Pazarcık and Mw 7.6 Elbistan earthquakes of February 6th, 2023: Contribution of valley effects on damage pattern

Karray M., Karakan E., KINCAL C., Chiaradonna A., Gül T. O., Lanzo G., ...Daha Fazla

Soil Dynamics and Earthquake Engineering, cilt.181, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 181
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1016/j.soildyn.2024.108634
  • Dergi Adı: Soil Dynamics and Earthquake Engineering
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), Communication Abstracts, Compendex, Environment Index, INSPEC, Metadex, Civil Engineering Abstracts
  • Anahtar Kelimeler: Amplification, Damage distribution, Elbistan, February 6th, 2023 Türkiye earthquakes, Ground motion, Pazarcık, Valley effect
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

On February 6th, 2023, southeastern Türkiye was shaken by two catastrophic earthquakes, close to northwestern Syrian border. The first earthquake (Pazarcık) occurred 45 km west of Gaziantep at 1:17:32 (UTC), with a shallow strike-slip faulting at a depth of approximately 8.6 km and a moment magnitude (MW) of around 7.7. The second event (Elbistan) took place 9 h later, 66 km north-east of Kahramanmaraş city center, also with shallow strike-slip faulting at a depth approximately 7 km and an MW of around 7.6. Turkish authorities reported a death toll of over 59,000 in Türkiye and about 8500 in Syria. The destructive effect of the earthquake resulted from widespread strong ground shaking, a rupture length exceeding 300 km, causing collapse of a large number of buildings. The catastrophic destruction of the built environment was accompanied by a range of other earthquake-related effects, including fault ruptures, landslides, and soil liquefaction. The aim of the study is to analyze the distribution of ground motion and their relationships with the observed damages for the two events. Spectral accelerations of key importance were assessed across a large area in the southeastern part of Türkiye. Notably, these accelerations were generally much higher than existing design spectra. A significant correlation between the observed concentration of damage and the significant amplification of motion induced by local soil conditions (such as soft soils and valley effects). The distinct tectonic structure of the region could be the main reason for the high amplification in the valleys (associated with basin effects), even at large distances from the epicenter, especially in correspondence with the bidimensional graben-type geological structures. The investigation delved into the analysis of four specific regions in detail: Antakya and Hassa (both in the Hatay province), Kahramanmaraş and Göksun. Notably, the observable valley effects were found to play a significant role and could account for the significant damage observed in these regions.