Explainer | Why was the Turkey-Syria earthquake so deadly?
- Very powerful tremors typically occur under water, but the 7.8-magnitude quake that has claimed thousands of lives took place on land
- The affected regions are heavily populated, and many of the buildings were vulnerable to collapse

A 7.8-magnitude earthquake followed by another strong tremor devastated wide swathes of Turkey and Syria on Monday, killing thousands of people.
What happened?
The quake hit at depth of 18km (11 miles) and was centred in southern Turkey, near the northern border of Syria, according to the US Geological Survey.
Many aftershocks rocked the two countries since the initial quake. In the first 11 hours, the region had felt 13 significant aftershocks with a magnitude of at least 5, said Alex Hatem, a USGS research geologist.
Another strong quake – magnitude 7.5 – hit Turkey nine hours after the main jolt. Though scientists were studying whether that was an aftershock, they agreed that the two quakes are related.
“More aftershocks are certainly expected, given the size of the main shock,” Hatem said. “We expect aftershocks to continue in the coming days, weeks and months.”
What type of earthquake was this?
Researchers said the earthquake was a strike-slip quake, where two tectonic plates slide past each other horizontally.
The Earth is divided up into different pieces, “kind of like a jigsaw puzzle”, said Eric Sandvol, a seismologist at the University of Missouri.