Akademik Veri Yönetim Sistemi
Şubat 2023 Depremleri ve Bölgemize Etkileri, Adana, Türkiye, 28 Şubat - 01 Mart 2024, cilt.1, sa.1, ss.40-44
Türkiye is a seismically active earthquake country, where mainly bounded by active faults and plates, located on the Alpine-Himalayan mountain belt. Our country has not faced earthquakes of the magnitude and number experienced in 2023 for a very long time. The main geological factor that causes these earthquakes to occur is the relative movements of the plates and platelets on the crust of the earth. As the African and Arabian plates move northward along the boundary of the Dead Sea transform fault zone in the south, these plates have been compressing and pushing the Anatolian Platelet in the north for a very long time. In addition, the Anatolian platelet is compressed between the Eurasian Plate in the north. Due to this tectonic settlement of our country, the Anatolian platelet in Turkey moves at a rate of 2.1 cm per year towards the west of the area where the Major Right-lateral Strike-slip North Anatolian Fault Zone and the Left Lateral strike-slip East Anatolian Fault Zone intersect around Karlıova. The primary reason for the occurrence of this earthquake is that the Transform Dead Sea Fault zone, which forms the border of the Afro-Arabian plate, extends into the borders of our country and the potential energy that it has accumulated for a very long time along this left lateral Eastern Anatolian Fault zone is instantly transformed into kinetic energy.The first earthquake with a magnitude of 7.8 occurred on 6 February 2023 at 4:17 am in the Sofalaca area, approximately 22 km west-southwest of Gaziantep. The aftershock of this earthquake was 6.8 magnitude and occurred just 11 minutes later, about 10 km southwest of the first earthquake, again in the Karasu graben, close to Nurdağı. With these earthquakes, 5 segments of the East Anatolian Fault Zone with a length of hundreds of kilometers were broken. After these earthquakes, the Sürgü-Çardak Fault Segment extending from the northern parts of the Eastern Anatolian Fault Zone, approximately 100 km north of the first earthquake, approximately 9 hours later on the same day, at 13:24, was triggered by the first earthquakes and a second big earthquake of 7.6 magnitude hit Kahramanmaraş Ekinözü village. The aftershock of the second earthquake occurred 98 minutes later, approximately 65 km west of the same segment, approximately 10 km north of Göksun District with a magnitude of 6. After these earthquakes occurred, left lateral displacements were detected on average around 3,5 meters in the field along the southern segments of the Eastern Anatolian Fault, and vertical displacement up to 1.5 meters, where the northern block generally uplifted. After these earthquakes, more than 8000 aftershocks occurred, and on 20.02.2023, the Antakya Fault (Hatay), which was in the extension of the Amanos Fault and had not been broken until that date, broke at 20:04 and caused another 6.4 earthquake to occur.This zone is the last piece to break on the land, and it reaches the southern parts of Cyprus with a transform fault boundary through the Mediterranean Sea in the southwest, and this boundary forms the boundary of the African plate-Anatolian platelet. The number of earthquakes and aftershocks that hit our 11provinces was over 60,000 throughout the year, 651 of which were >4-4.9 in magnitude, and 57 were 5 or above in magnitude. On February 6, 2023, 31 earthquakes of magnitude 5 and above occurred and their aftershocks during one day. 7 aftershocks of magnitude above 5 occurred on February 7 and 3 on February 8. During and after these earthquakes, much smaller surface deformations developed in the immediate vicinity of Adana province than the main earthquake region. A total of 22 aftershocks with magnitudes of 4-5.5 occurred within the borders of the Adana region throughout the year, mostly in the Saimbeyli- Tufanbeyli and Aladağ regions. Only one of these has a magnitude of 5.5 and occurred on 25th July 2023 around Minnetli village, approximately 20 km north of Kozan. The other 21 aftershocks are between magnitude 4-4.9.