PRELIMINARY OBSERVATIONS AFTER THE 2020 AEGEAN SEA EARTHQUAKE

Abstract

The October 30, 2020 Aegean Sea Earthquake occurred with a magnitude of M6.6 and caused significant damages across the city of Izmir, Turkey. Specifically, this paper presents the preliminary observation results based on; ground motion properties, local site conditions, code-based design procedures, and the structural damage mechanisms. In order to achieve this purpose, critical spectral characteristic of strong ground motion records were evaluated in advance. Then, the variables given in code-based design results were investigated based on base shear to structural weight ratio. Local site effects were considered by comparing the spectral amplitudes obtained for different strong ground motions recorded from stations with different soil characteristics (i.e. the shear wave velocity (VS30) averaged over top 30m of the soil profile). Primary temporal distributions of recorded earthquake sequences followed by the mainshock were detailed and the directionality characteristics of the strong ground motion recorded after the mainshock were summarized. Moreover, observed damage patterns in buildings are discussed and possible reasons were identified in terms of critical structural properties. Preliminary results generally represent the effect of local soil characteristics on the amplification of spectral properties.