Updated historical earthquake catalog of İzmir region (Western anatolia) and its importance for the determination of seismogenic source

Abstract

Although destructive earthquakes have not occurred in the instrumental period except for the 30 October 2020 Samos earthquake (Mw = 6.6), the records show that there were significant earthquakes that caused great destruction in İzmir and its surroundings in the historical period. However, it is not yet clear which faults are causative for these earthquakes affecting İzmir and its surroundings. For this purpose, it has been attempted to determine new geological, seismological and environmental data by examining a large number of original sources, records and old international earthquake catalogs, other than the existing national catalogs used in seismicity studies in Turkey. In this context, a new local and updated historical earthquake catalog was prepared for İzmir and its immediate vicinity. The data obtained from the records show that the maximum intensity of some destructive historical earthquakes in the İzmir region was X. This means that the active faults in İzmir and its immediate vicinity have the potential to generate earthquakes of up Mw = 7.1 in the future. Details on historical earthquakes strengthen the possibility that these earthquakes may have been generated by active faults located near the İzmir city settlement. The isoseismic maps created for the first time using historical data, point out that the highest seismic intensity in the 178, 1688 and 1778 A.D. earthquakes caused destruction in the İzmir city center and nearby settlements indicate that they were concentrated at a relatively small area in the Bay of İzmir, and tectonically in the hanging-wall of the İzmir Fault. In the most likely scenario, all these damages observed may be attributed to the western segment of the İzmir Fault (Balçova segment) since it was defined as the only seismic source around the İzmir Bay in the updated active fault map of Turkey, of course, these data should be verified by performing detailed paleoseismological studies.