Preliminary Analysis of the Aftershock Sequence of the February 6, 2023, Turkey Earthquake

Abstract

The February 6, 2023, Turkey earthquake with a moment magnitude (Mw=7.8) will be recognized as one of the most powerful earthquakes to strike a large metropolitan area in recent memory. This quake occurred in southern Turkey near the northern border of Syria along the southern western branch of the East Anatolian Fault (EAF). This major event was followed by numerous significant aftershocks, with 14,107 earthquakes occurring as of March 5, 2023. Preliminary data analysis in this study of aftershocks a month after the main earthquake (Mw=7.8) indicates that the majority of the aftershock sequence concentrated near the epicenter of the main shock displaced numerous fault segments within the EAF zone and can have indirect effects on neighboring fault systems. As a result, notable earthquake activity was observed along the northern section of the Dead Sea Transform (DST) fault system in Syria, Lebanon, and Palestine. According to statistical seismological analysis, 81% of aftershocks with magnitudes less than 3 occurred after the main shock, while 38 aftershocks with magnitudes 5 or greater occurred within the first 6 days, that includes 7.5 and 6.8 magnitude shocks. The depth distribution of the large main shocks and the aftershocks was located at shallower crustal depth. The aftershock sequence is mostly distributed in the first 15 km of the earth's crust, with significant occurrences occurring between 5 and 19 km deep. The expected aftershock scenario of such a large earthquake is to continue for several months or longer, possibly years. The interaction of the EAF and the DST fault is a significant topic for study since it may well provide insights into the general tectonic activity and assist in better predicting future earthquakes in the region