Over 2000 feared killed in Turkey’s worst-ever back-to-back earthquakes

(Dr. R K Chadha)
Hyderabad: A very powerful earthquake of magnitude 7.8 of magnitude struck Central Turkey on Monday in the early hours at 4:17 am local time, when people were fast asleep. This was followed by yet another two of 7.5 that followed within hours. Reports claim that as many as 2000 people feared being killed and colossal destruction of property loss. The death toll is likely to rise.
The earthquake occurred at a depth of about 18 km below the surface of the earth. In the last 14 hours, more than 30 aftershocks were reported from the region in the magnitude range between 4.5 and 7.5, the last one being the largest aftershock at around 1:25 pm with a magnitude of 7.5 on the Richter scale. The main earthquake and the aftershocks are all shallow, i.e., less than 20 km below the surface and hence there is great devastation. All the earthquakes are occurring along a NE-SW trending strike-slip fault starting near Iskenderun at the south-western tip of the north-Syrian-south Turkey border and going up to Malatya in Central Turkey.
So, the earthquakes have ruptured a fault length of about 200 km with a width of approximately 25 km. The main earthquake today morning started in the close vicinity of a triple junction between the Anatolia, Arabia and African plates and the mechanism of faulting is in conformation with the tectonics of the region where earthquakes occur frequently along East Anatolia fault zone and the Dead Sea transform fault zone. Today’s morning earthquake occurred in the seismically active region of southern Turkey where three earthquakes of magnitude 6 or larger have occurred within 250 km from the epicenter since 1970. The largest of the three was a magnitude 6.7 that occurred northeast of the present earthquake on January 24, 2020. Historically, southern Turkey and northern Syria have experienced significant and damaging earthquakes in the past. Aleppo, in Syria, was devastated several times by large earthquakes of magnitude >7.0 in the past in 1138 and 1822 but the precise locations and magnitudes of these earthquakes can only be estimated. As per some records, the 1822 earthquake claimed human lives between 20,000-60,000.
The earthquakes in Turkey occur as the southern region of the country is located in a complex tectonic region where the interaction of the Africa and Arabia plates and the Anatolia block occurs. This involves translational motion of the Anatolia Block westwards, with a speed of approximately 25mm/yr concerning Eurasia, to accommodate the closure of the Mediterranean basin.