Stress Tensor and Coulomb Analysis for Erzurum and Its Surroundings

Öz

ln this study, the dominant stress regime was investigated by stress tensor analysis, and stress change was modelled by Coulomb stress analysis for Erzurum and its surroundings. The data set consists of 58 earthquakes (4.0≤M_w≤6.9) focal mechanism solutions, occurred between 1966 and 2019 for both analyses. According to the stress tensor analysis results, the largest (σ1) and smallest (σ3) principal stress axes are horizontal and the middle principal stress (σ2) axis is vertical, which are compatible with strike-slip faults due to the tectonic regime in the region. Based on focal mechanism solutions, Coulomb stress variation was obtained by using azimuth and dip values of the principal stress axes. Especially, increase in stress is observed in the North Anatolian Fault Zone, Horasan-Narman fault and Askale fault.

Anahtar Kelimeler

• Coulomb Stress Analysis,Stress Tensor Analysis,Eastern Anatolian Fault Zone,North Anatolian Fault Zone

Erzurum ve Çevresi İçin Gerilme Tensör ve Coulomb Analizleri

Öz

Bu çalışmada Erzurum ve çevresi için gerilme tensör analizi ile hâkim gerilme rejimi araştırılmış, Coulomb gerilme analizi ile gerilme değişimi modellenmiştir. Her iki analiz için veri seti 1966-2019 yılları arasında meydana gelen 58 adet depreme (4.0≤M_w≤6.9) ait odak mekanizması çözümlerinden oluşmaktadır. Gerilme tensör analiz sonuçlarına göre en büyük (σ1) ve en küçük (σ3) asal gerilme eksenleri yatayda, orta asal gerilme (σ2) ekseni ise düşeyde çıkmış ve bu sonucun bölgedeki tektonik rejime bağlı doğrultu atımlı faylar ile uyumlu olduğu görülmüştür. Odak mekanizma çözümlerinden hareketle azimut ve dalım değerleri kullanılarak Coulomb gerilme değişimi elde edilmiştir. Özellikle Kuzey Anadolu Fay Zonu, Horasan-Narman Fayı ve Aşkale Fayında gerilmelerde artış olduğu tespit edilmiştir.

Anahtar Kelimeler

• Coulomb Gerilme Analizi,Gerilme Tensör Analizi,Doğu Anadolu Fay Zonu,Kuzey Anadolu Fay Zonu

Kaynakça

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