Deprem Etkileşimlerinde Coulomb Gerilme Kriteri Değerlendirmesi; Doğu Anadolu Fay Hattı

Yıl 2018, Cilt: 8 Sayı: 2, 523 - 535, 01.06.2018

Ayse Bengu Sunbul Fatih Sunbul

Öz

Türkiye’nin önemli fay zonlarından biri olan Doğu Anadolu Fay Zonu DAFZ , içinde bulunduğumuz yüzyılda çok aktif görünmemesine rağmen, tarihsel dönemlerde büyük depremler üretmiş bir fay zonudur. DAFZ’in yakın çevresinde büyük yerleşim birimlerinin bulunması, dolayısıyla gelecekte meydana gelebilecek muhtemel bir depremin yerinin belirlenmesi önem arz etmektedir. Fayların içinde bulundukları gerilme durumları ve komşu faylara olan etkisi Coulomb gerilme kriteri ile modellenebilmekte, gerilmenin arttığı bölgeler tespit edilerek, gelecekte oluşabilecek bir deprem lokasyon olarak değerlendirilebilmektedir. Bu çalışmada DAFZ uzerinde 1822 yılından günümüze kadar meydana gelmiş orta ve büyük ölçekli depremler Coulomb kriteri kullanılarak modellenmiş ve incelenen depremlerin birbirleri ile olan ilişkileri araştırılmıştır. Ayrıca, lehva hareketlerine bağlı meydana gelen tektonik gerilme değişimleri analiz edilerek, bölgede deprem riski oluşturabilecek gerilmenin yüksek olduğu alanlar incelenmiştir. Elde edilen bulgulara göre; modellenen 18 depremden 12 tanesi oluşumları itibariyle gerilme ilişkileri tespit edilmiş ve bir anlamda birbirlerini tetiklemişlerdir. Geçmiş yıllarda araştırmacılar tarafından gerilme artışı saptanan Elazığ-Bingöl arasındaki segmentin 2003 Bingöl ve 2010 Elazığ depremlerinden sonra kısmen deprem riski taşımadıgı da tespit edilmiştir. Inceleme alanında yer alan Kahramanmaraş-Malatya illeri arasında yer alan segmentte hem deprem tetiklemelerinden, hem de tektonik hareketlerden kaynaklı bir gerilme artışı tespit edilerek, deprem riskinin yüksek olduğu alan olarak çalışmada belirlenmiştir

Anahtar Kelimeler

Coulomb gerilme analizi, Doğu Anadolu Fay Zonu DAFZ, Gölbaşı-Türkoğlu segmenti, Sismik tehlike

Evaluation of Coulomb Stress Criteria in Earthquake Interactions; East Anatolian Fault Line

Öz

East Anatolian Fault Zone EAFZ , one of Turkey’s major fault zones, is quiescent in this century, was very active and produced major earthquakes in historical periods. In terms of large cities existence along the EAFZ, It is important to identify a possible location of the earthquake that may occur in the future. The stress state in the faults and their possible triggering effect to neighboring faults can be modelled by the Coulomb stress criterion. Hence, the future earthquake location can be determined by detecting the stress increased areas. In this study, moderate and large earthquakes that have been occurred since 1822 were modelled using the Coulomb criterion and their stress interactions were investigated. In addition, by analyzing the tectonic stress changes due to plate motions, the areas where the positive stress change is high, which may create earthquake risk in the region, were also investigated. According to the study findings; 12 of the 18 modelled earthquakes have a causal link between their occurence; it can be concluded that the earthquakes were triggered by their subsequent ones. Furthermore, the segment between Elazığ and Bingöl cities, where the stress increased area examined by the researchers in the previous years, was currently determined to be partially relaxed following the 2003 Bingöl ve 2010 Elazığ earthquakes. In conclusion, the segment between Kahramanmaraş and Malatya cities was determined to be a seismic hazard which poses a high earthquake risk due to both earthquake interactions and tectonic movements modelling.

Anahtar Kelimeler

Coulomb stress analysis, East Anatolian Fault Zone EAFZ , Gölbaşı-Türkoğlu segment, Seismic hazard

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