How Turkey’s Anatolian Fault System Causes Devastating Earthquakes

The major earthquake and large aftershock in Turkey on Monday are two of more than 70 quakes of magnitude 6.5 or higher recorded in the region since 1900. Turkey’s two main fault zones — the East Anatolian and the North Anatolian — make it one of the most seismically active regions in the world.

Magnitudes of major earthquakes since 1900

Map showing the East Anatolian and North Anatolian fault zones in Turkey. Points are overlaid on the map showing the locations of major earthquakes in the region since 1900.

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

These fault zones are a result of movement of large portions of Earth’s crust, or tectonic plates, relative to each other. One zone includes the Anatolian Plate, which makes up most of Turkey. The East Anatolian zone encompasses the area where there is movement of the Anatolian Plate relative to the Arabian Plate to the southeast. The North Anatolian zone is where there is movement of the Anatolian Plate and the Eurasian Plate to the north.

The main quake on Monday was one of the most powerful earthquakes ever recorded in the area, matching the magnitude of a earthquake that killed about 30,000 people in December 1939 in northeast Turkey.

Deaths in major earthquakes since 1990

Around Turkey and northern Syria. Circles are sized by the number of estimated deaths.

Chart showing year and the number of deaths in earthquakes.


turkey, 2023

as of 5 p.m. E.T. on Feb. 6

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