hide
Free keywords:
-
Abstract:
The region of the East Anatolian Fault (EAF) experienced several strong earthquakes during the instrumental period of seismology, i.e. after AD 1900. However, the devastating earthquake (Mw7.8) of 6 February 2023, that ruptured along the EAF, is the first to occur with such a large magnitude in that time interval. Then, some questions of fundamental importance for the earthquake cycle in the EAF raise. When earthquakes of similarly large magnitudes occurred in the past? Which segments of the EAF ruptured? What is the mean repeat time of the large EAF earthquakes? To respond to such challenging issues we organized a data base of historical earthquakes that caused significant damage in the region of EAF and assigned macroseismic intensities in terms of MMI scale. Earthquake magnitudes were calculated from empirical magnitude/intensity relationships. Mapping of lateral rupture zones along the EAF was based on higher degree isoseismal curves (e.g. degree VIII) and on evidence of surface-fault traces and other ground failures. Preliminary results showed that rupture zones of the large magnitude earthquakes abut and do not overlap, while the repeat times are of the order of several hundred years.
