Determination of volcanic structures in and around Nevsehir by seismic attenuation method


ŞAHİN Ş., ÖKSÜM E.

JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, vol.35, no.1, pp.181-191, 2020 (SCI-Expanded) identifier identifier

Abstract

The Quaternary volcanism is intense in Nevsehir and its vicinity. These areas show high seismic attenuation characteristics. Three dimensional (3-B) P and S wave attenuation (Q(p)(-1) and Q(s)(-1)) were determined. P wave attenuation is sensitive discontinuity in the crust and S wave attenuation is sensitive to fluid reservoirs. The data that 1541 signals from 815 earthquakes were recorded by six broad-band stations belonging to Bogazici University Kandilli Observatory and Earthquake Research Institute. The Coda Normalization Method was applied to reveal the 3-D attenuation structure. After the determination of P, S, and code phases of the earthquakes, the inverse solution technique was used. The computer program is used based on the energy ratio of the P and S wave amplitudes to the code amplitude based on the MuRAT-V.1 written in Matlab code. With this software, P and S wave attenuation (Q(p)(-1) and Q(s)(-1)) values in Nevsehir and its surroundings were determined by using the inverse solution technique according to the wave path velocity differences by moving from the amplitude ratios. In the region, it is seen that the attenuation is high in the Melendiz Mountain and Aladaglar (Nigde) surroundings and the northwestern part of Mount Erciyes.