Akademik Veri Yönetim Sistemi
Turk Deprem Arastirma Dergisi, cilt.3, sa.2, ss.167-192, 2021 (Scopus, TRDizin)
In this study, moment tensor analyses of microearthquakes recorded with the MONGAN-1 and MONGAN-2 seismic networks deployed on the Ganos Fault are done. The MONGAN-1 seismic network consists of 40 short-period stations located in a local area of approximately 10 km2, and the general feature of the earthquakes used is that they are out of the network. The effect of the azimuthal coverage of the seismic network, behaving like a point receiver covering a narrow azimuthal range for moment tensor analysis of microearthquakes, is investigated. For this purpose, 61 microearthquakes with magnitudes varying between 1.5≤Mw≤3.7, occurred between October 2017 and June 2020 in the region between Tekirdağ Basin and Ganos Fault, are analyzed. Broadband national network records of 10 earthquakes with magnitudes ranging between 2.8≤Mw≤3.7 are used to determine the focal mechanisms using both moment tensor inversion and P wave first motion polarities techniques and then are compared with the MONGAN network’s solutions. Although there are minor differences in the strike, dip and rake angles of the focal mechanisms obtained, it is observed that the three focal mechanism analysis results are generally compatible with each other. Although the azimuthal coverage of the seismic network is not good, moment tensor inversions of the microearthquakes can be successfully applied with an accurate crustal model. As a result of the stress analysis, the principal stress axes orientations of σ1, σ2 and σ3 are obtained as 277.2/42.8, 87.7/46.7 and 182.9/4.7 (azimuth/dip), respectively. The stress ratio in the region is calculated as 0.60.