A Review on Kandilli Observatory and Earthquake Research Institute (KOERI) Seismic Network and Earthquake Catalog: 2008–2018

Abstract. KOERI has a long history of earthquake seismology, beginning its observations right after the devastating earthquake on 10 July 1894 in Istanbul, by deploying the first seismograph in the region. Naturally, its seismic network and earthquake catalog evolved since that time, in harmony with the progress in the science of seismology. Currently, the seismic network consists of 242 stations that record approximately 1500 earthquakes per month during periods of regular seismicity. Magnitude is one of the most critical parameters in determining the size of an earthquake, especially in seismic hazard assessment studies. The objective of this study is to homogenize the magnitudes of the KOERI catalog between 2008 and 2018. For this aim, we computed the Magnitude of Completeness ( Mc ) for two different time periods between 2008–2011 and 2012–2018 by taking into account the duration magnitude ( Md ) and local magnitude ( Ml ), where these parameters might not be available jointly for the both time periods considered. As a result, we present a relationship of Md and Ml magnitudes derived from and applicable to KOERI's earthquake catalogs.