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.

Eurasian

Plate

Bulgaria

North Anatolian

Fault

Istanbul

Ankara

Iran

Turkey

East Anatolian

Fault

Feb. 6

Gaziantep

Anatolian Plate

Greece

Arabian Plate

Syria

Iraq

Beirut

Earthquake

magnitude

Damascus

African Plate

8

7

200 miles

6

Eurasian Plate

North Anatolian

Fault

Istanbul

Ankara

Turkey

East Anatolian

Fault

Feb. 6

Anatolian Plate

Arabian Plate

Syria

Iraq

Earthquake

magnitude

Beirut

Damascus

8

Tel Aviv

7

200 miles

6

Sources: National Oceanic and Atmospheric Administration; United StatesGeological Survey Notes: Includes earthquakes since 1900 that are classified as significant earthquakes by the National Centers for Environmental Information based on a series of criteria including deaths, damage and magnitude.

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.

Magnitude

1900

1920

1940

1960

1980

2000

2023

4

5

6

7

8

turkey, 1939

Magnitude

7.7

Est. deaths

32,700

armenia, 1988

Magnitude

6.8

Est. deaths

25,000

turkey, 1999

Magnitude

7.6

Est. deaths

17,118

turkey, 2023

Magnitude

7.8

Est. deaths

3,800

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

Sources: National Oceanic and Atmospheric Administration; United States Geological Survey Notes: Major earthquakes are those classified as significant earthquakes by the National Centers for Environmental Information based on a series of criteria, including deaths, damage and magnitude. Death tolls are estimates and are approximately assigned to the related event.