## 2 Materials and Methods  
_Seismicity of the Eastern Anatolia Region_  
The region is located where the Arabian and African Plates move toward the Eurasian Plate. This compressional regime controls the formation of many active faults and the seismicity of the region. The general tectonic structure of the region is mainly controlled by the deformation zone known as the Bitlis Zagros Thrust Fault Belt (BZTFB), where the northward-moving Arabian Plate collides with the Anatolian Plate. The dominant fault zones in the region are the East Anatolian Fault Zone (EAFZ), the North Anatolian Fault Zone (NAFZ), and the BZTFB. The collision is managed through the Karlova Triple Junction, where the right lateral strike-slip NAFZ joins with the left lateral EAFZ (Figure 2). Additionally, to the east of this junction, the dominant elements are mostly NW-SE striking right-lateral and NE-SW striking left-lateral faults. The E-W striking Mus, Lake Van, and Pasinler ramp basins are the other significant tectonic elements in the Eastern Anatolian Region. Due to this active tectonic regime mentioned above, the region has experienced numerous earthquakes so far. The distributions of the historical and recent earthquakes (Ms \(\geq\) 3.0) produced from the database of the DEMP for the country are given in Figure 3.  
After the collision of the Eurasian and Arabian Plates, Eastern Anatolia has contracted an average of 40-60% in the N-S direction in the last 10 million years (which began in the Middle Miocene in the neotectonic period), and the Earth's crust has thickened and increased in the region [50]. The NAFZ and the EAFZ limit the Eastern Anatolia Region in the west. As a result of the compression in the region, generally, E-W striking, N- or S-dipping high-angle thrusts, folds with E-W striking axes, left-lateral strike-slip faults with NE-SW striking, right-lateral strike-slip faults with NW-SE striking, and N-S striking extensional fractures and volcanic activity related to these fractures were formed. In the region and to the north in the Caucasus, the N-S compression movement was found to be 30 mm/year, and it was stated that 10-40% of the deformation here was related to  
Figure 2: Simplified neotectonic and relief maps of Turkey and the surrounding area [45; 46; 47; 48; 49]. SBT: Southern Black Sea Thrust; NAFZ: North Anatolian Fault Zone; NEAFZ: Northeast Anatolian Fault Zone; WAEP: West Anatolia Extensional Province; EAFZ: East Anatolian Fault Zone; DSFZ: Dead Sea Fault Zone; BZTFB: Bitlis Zagros Thrust Fault Belt. earthquakes. A significant part of the deformation passes over the EAFZ, which forms the border of this region with the Anatolian Plate in the west. In the region, inter-mountain depression basins have formed lateral slip faults, opening cracks, folded-thrust areas, and Plio-Quaternary (2 my) volcanic eruptions by jamming [51]. Most of the earthquakes in the region occurred at depths of 2-10 km. Except for the EAFZ, one of the main active faults in the region is the Narman-Horasan Fault, which is a left-sided strike-slip fault [52]. The northern part of this fault produced the Narman earthquake (1983). The Caldran Fault is a right-sided strike-slip, and it produced the Caldran earthquake (1976). An average surface rupture of 50 km was observed. The Tendurek-Balkgol Fault contains normal faults in the Balkggolu section and becomes a distinctly right-sided strike-slip fault toward the southeast of the lake. It was stated that the 1840 Agrn earthquake was related to this fault [53]. The Karayazi Fault is located parallel to the Tutak Fault at a distance of 15-20 km. Both faults are right-handed and strike-slip [54]. The Erzurum-Tortum Fault has left-sided strike-slip characteristics. The width of the area covered by shear cracks along the belt is up to 10 km. The southern part of this fault produced some earthquakes that caused significant losses in the vicinity of Erzurum province in 1200, 1482, and 1859 [53]. Some of the historical earthquakes that  
Figure 3: Historical and recent seismicity in Eastern Anatolia.