Velocity changes across the Ganos segment of the North Anatolian Fault Zone in NW Turkey from systematic variations in body wave arrival times

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Yalçinkaya E., Bohnhoff M., Martinez-Garzon P., Görgün E., Pinar A., Alp H.

EGU General Assembly 2021, Vienna, Avusturya, 19 - 30 Nisan 2021, cilt.8152, ss.1, (Özet Bildiri)

• Yayın Türü: Bildiri / Özet Bildiri
• Cilt numarası: 8152
• Doi Numarası: 10.5194/egusphere-egu21-8152
• Basıldığı Şehir: Vienna
• Basıldığı Ülke: Avusturya
• Sayfa Sayıları: ss.1
• Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
• İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

Imaging and characterizing transform fault sections that are capable to produce large earthquakes

is crucial for evaluating seismic hazard and subsequent risk for nearby population centers. The

Marmara Fault near the megacity of Istanbul is one of the best defined seismic gaps in the world

and its complexity is captured by seismological, geodetic and geological data. A local dense seismic

array (MONGAN) provides a high resolution data set allowing to image the Ganos fault separating

two different geological units in the western Marmara region. First results of the waveform

analysis from this array present systematic early-phase arrivals at the seismic stations located on

the northern block of the Ganos fault which comprises geological units including older and more

compact materials than that of the southern block. This difference in the arrival times causes the

earthquake epicenters to shift further north than the real locations. In this preliminary results, the

early-arrivals will be evaluated according to source azimuths and distances, and possible earth

models and wave paths will be discussed. The results have implications for rupture directivity

during future earthquakes as input for hazard and risk models for the Marmara region.