How Turkey’s Anatolian Fault System Causes Devastating Earthquakes

The large earthquake and large aftershocks in Turkey were two of more than 70 earthquakes with a magnitude of 6.5 or greater recorded in the region since 1900. Turkey’s two main fault zones – Eastern Anatolia and Northern Anatolia – are among the most seismic. active areas of the world.

The 7.8-magnitude earthquake at 4:17 am local time, and the unusually large 7.5-magnitude aftershock nine hours later, were both on the East Anatolian Fault Zone. But there have also been several deadly earthquakes along the North Anatolian Fault Zone, including one in 1999 about 60 miles from Istanbul that killed about 17,000 people.

These fault zones are the result of the movement of large parts of the earth’s crust, or tectonic plates, relative to one another. One zone includes the Anatolian Plate, which makes up most of Turkey. The Eastern Anatolian Zone covers the area where the Anatolian Plate moves relative to the Arabian Plate to the southeast. The North Anatolian Zone is where the Anatolian Plate and the Eurasian Plate move to the north.

Monday’s main quake was one of the strongest on record in the region, matching the magnitude of the December 1939 quake that killed around 30,000 people in northeastern Turkey.