Moment Magnitude Estimates in the Marmara Sea Region (NW Turkey) Using Coda Wave Analysis

Abstract

<p>Reliable magnitude estimates of the earthquakes are of utmost important for seismic hazard studies, particularly, in tectonically active areas such as the Marmara region of NW Turkey. The region is highly populated and contains a major fault associated with destructive earthquakes. In this study we apply a coda wave modelling approach based on acoustic radiative transfer theory to calculate the source displacement spectrum, and thus to obtain moment magnitudes of small earthquakes within the Marmara region. We examine three-component waveform data extracted from local earthquakes with magnitudes 2.5 ≤ M<sub>L</sub> ≤ 5.7 recorded in a radius of 150 km. For each event in the region, an inversion is performed in several different frequency bands. Our results indicate significant similarity with the local magnitude values reported by the KOERI. Consequently, we focus on establishing a novel relation between M<sub>w</sub> and M<sub>L</sub> in the Marmara region.</p>