The Science of Earthquakes: Why Turkish Quake Hit Hard

This story was last updated: February 7 @ 10:17 PM EST. 

The short answer to why a large earthquake struck southeastern Turkey and northern Syria is that the area was due for one. Nearly 8,000 were killed in the quake. 

The more complicated one is a blend of factors. They include the movement of tectonic plates and the depth of the quake. The earthquake happened close to big cities. Also, many of the buildings weren't built to withstand such a disaster. 

There are two types of earthquakes: volcanic and tectonic. Monday’s quake was the latter. Turkey is a hotspot for earthquakes. It sits on two fault lines which are affected by the movement of three rock slabs known as tectonic plates: the African, Anatolian, and Arabian. Tectonic plates are under the Earth's surface. As the plates move, the Earth shakes. 

This quake occurred along the 300-mile East Anatolian fault. It separates the Anatolian and Arabian plates. Most of Turkey’s deadliest quakes in the past 100 years occurred along the 930-mile North Anatolian. It runs across northern Turkey. They include a similar 7.8 magnitude quake in 1939. 

Fatih Bulut is a seismologist at Boğaziçi University in Istanbul. He told NPR that the recent quake “is not a surprise for us.”

The quake struck 11 miles below the surface, according to the US Geological Survey (USGS). That's pretty shallow. Scientists say that created more shaking at the ground level. The USGS also said that people in the area tend to live in “unreinforced brick masonry” buildings. Those structures are “vulnerable,” the USGS said.