Northern Aegean Earthquake (Mw=6.9): Observations at three seismic downhole arrays in Istanbul

The Northern Aegean Earthquake (Mw=6.9\ML=6.5) took place on May 24, 2014 between the islands of Gokceada, Turkey and Samothraki, Greece. The tremors were felt as far as in Istanbul, about 300 km on the East - Northeast (ENE) side of the epicenter. Kandilli Observatory and Earthquake Research Institute (KOERI) of Bogazici University, Turkey operate three downhole arrays in Istanbul, namely Atakoy (ATK), Fatih (FTH) and Zeytinburnu (ZYT) arrays. In this study, waveforms and site response observed at the KOERI operated seismic downhole arrays during the May 2014 Northern Aegean Earthquake (NAE2014) are analyzed in detail and presented. Evaluation of the acceleration records have shown low amplitude but long period and long duration motions at Istanbul. Furthermore, the analyses of the recordings suggest that Vs30 alone may not be a sufficient parameter for the characterization of site amplification.