Büyük Menderes Grabeninde Cisim Dalgalarının Frekans Bağımlı Soğrulma Karakterinin Belirlenmesi

Bu çalışmada, Büyük Menderes grabeninin kuzey sınırı boyunca gelişen fay toplulukları ve bunların Ege Denizi’ne doğru uzantıları boyunca oluşmuş 66 deprem verisi kullanılarak bölgeye ait soğrulma karakteristikleri ortaya konmaktadır. Çalışmada, P ve S dalgalarının soğrulma fonksiyonları, koda normalizasyon tekniği ile hesaplanmıştır. Çalışma kapsamında elde edilen sonuçlar, bölgede veya yakın civarında gelecekte olması muhtemel büyük depremlerin daha doğru bir şekilde modellenebilmesi ve sismik risk çalışmalarının da daha güvenilir sonuçlar elde edilmesi için gerekli olan temel parametrelerden biri olan sönüm ilişkilerini ortaya koymaktadır. Buna göre, S ve P sismik fazları için sırasıyla, Qs=79.2±14.6f 0.9±0.07 ve Qp=32.9±13.7f1.05±0.16 fonksiyonları elde edilmiştir. Ayrıca 1 Hz’ den büyük frekanslarda QS/QP oranı ortalama ~1.75 olarak hesaplanmıştır. Elde edilen sonuçlara göre düşük Qp ve Qs değerleri ve bunların oranları (QS/QP) saçılma etkisinin fazlalığını işaret etmekte ve bunun da çalışma alanındaki özellikle üst kabuktaki yoğun yanal heterojenitenin bir sonucu olduğu şeklinde yorumlanabilmektedir.

Frequency Dependent Attenuation Characteristics of Body Waves in Büyük Menderes Graben

In this study, 66 earthquake data, along the faults of northern boundary of the Büyük Menderes Graben and their continuations in the Aegean Sea, were used to reveal the body wave attenuation characterization of the region. The attenuation functions of the P and S waves are calculated by the coda normalization technique. The results obtained in this study reveal attenuation relations, which are one of the basic parameters required to modelling large earthquakes in the region and to obtain more reliable results from necessary seismic risk studies. The power-law functions were obtained for the S and P seismic phases as Qs=79.2±14.6f 0.9±0.07 and Qp=32.9±13.7f1.05±0.16 respectively. Also the QS / QP ratio is calculated as ~ 1.75. for the frequencies greater than 1 Hz. According to the results, the low Qp and Qs values and their ratios (QS / QP) indicate the abundance of scattering effect, which can be interpreted as a result of intense lateral heterogeneity in the upper crust.

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ISSN: 2528-9640
Yayın Aralığı: Yılda 2 Sayı
Başlangıç: 2015
Yayıncı: Artvin Çoruh Üniversitesi Doğal Afetler Uygulama ve Araştırma Merkezi