## 2 Regional Tectonics and Earthquake Overview  
Turkey is located at the convergence of Eurasia, on the Anatolian Plate, which is affected by the interaction of several adjacent plates and fault zones [14], as shown in Figure 1: The Arabian Plate squeezes the Anatolian Plate to the northwest, forming the East Anatolian Fault Zone that is the most active fault zone in Turkey in recent years; The African Plate, located south of Turkey, subducts northward under the Eurasian Plate, forming the Greek Island Arc, which is the most active subduction zone in Europe; The Eurasian Plate, located north of Turkey, compresses Turkey's northern part southward, forming the North Anatolian Fault Zone, which is a right-lateral strike-slip fault zone extending from the northwest of Turkey to the east of Georgia, and also the longest fault zone in Turkey [15; 16; 17].  
The exact time of this earthquake was 01:17 (UTC) on 6 February 2023, and its seismogenic fault was a segment of the East Anatolian Fault Zone [18]. The fault zone stretches about 700 km from the eastern to the central-southern part of Turkey, forming a deformation-type tectonic boundary between the Anatolian Plate and the northward-moving Arabian Plate. The slip rate in the eastern part is 6-10 mm/year, and in the western part is 1-4 mm/year [19]. The fault can also be divided into different directions of secondary faults, with mostly left-lateral slip, and locally showing thrust or normal faults [18].  
The epicenter was located in Pazarck district of Kahramanmaras city in Gaziantep province of Turkey, with a focal depth of 10 km. This earthquake caused extremely severe disasters in southern Turkey and northern Syria and was the strongest earthquake in the region in more than a hundred years [20]. (See Table 1 for details of the earthquake).  
The earthquake caused a direct economic loss of USD 34.2 billion [21] in Turkey and resulted in massive casualties and building damage. It killed 59,259 people, which made it the deadliest one in Turkey since 1900 [21]. Gaziantep city was the most severely affected city, with more than 15,000 people dead and more than 30,000 injured. The Sehitkamil district, which was closest to the epicenter, had 12,141 buildings destroyed or severely damaged, with a building damage rate of more than 80% [20]. The Gaziantep Castle was the oldest building damaged in the earthquake, with a history of more than two thousand years, and it possessed extremely precious cultural value [22]. Figure 2 shows the comparison of the castle before and after the earthquake. The earthquake also caused serious disasters in Hatay, Kahramanmaras, Malatya, Adiyaman, Diyarbakir, Sanlurfa, Mardin, and other cities and regions. These seismic damages included building collapse (see Figure 3), surface rupture (see Figure 4), landslide (see Figure 5), sand soil liquefaction (see Figure 6), and so on [23; 24; 25].  
Figure 1: Schematic diagram of the relevant plates and active faults around Turkey. (The plate boundaries are depicted by blue dashed lines. The motion directions of the plates are indicated by light blue thick arrows. The East Anatolian Fault (EAF) and the North Anatolian Fault (NAF) are shown by red and orange curves, respectively. The motion of the faults is indicated by dark blue bidirectional arrows. The seismic stations are depicted by black triangles. The figure also shows the earthquakes with Mw 5.0 or above that occurred within and around the Anatolian Plate since 1900. The epicenters are depicted by circles with solid dots, and the size of the circles corresponds to the earthquake magnitude. This figure demonstrates the complex tectonic setting of Turkey and the high seismic hazard in the region).