Why Turkey remains prone to earthquakes? What are aftershocks and why do they occur?

Turkey sits on top of major fault lines such as the North Anatolian Fault, and is frequently shaken by earthquakes. Some 18,000 were killed in a similarly powerful earthquakes that hit northwest Turkey in 1999.

Istanbul, Feb 6: A powerful 7.8 magnitude earthquake rocked wide swaths of Turkey and Syria on Monday, toppling hundreds of buildings and killing more than 2,300 people.

Hundreds were still believed to be trapped under rubble, and the toll was expected to rise as rescue workers searched mounds of wreckage in cities and towns across the area.

The quake, which was centred on Turkey's southeastern province of Kahramanmaras, was felt as far away as Cairo. It sent residents of Damascus rushing into the street, and jolted awake people in their beds in Beirut.

The US Geological Survey measured Monday's quake at 7.8. Hours later, a 7.5 magnitude one struck more than 100 kilometres (60 miles) away. An official from Turkey's disaster management agency said it was a new earthquake, not an aftershock, though its effects were not immediately clear. Hundreds of aftershocks were expected after the two temblors, Orhan Tatar told reporters.

Why does Turkey have many earthquakes?

Turkey experiences frequent earthquakes because it is located at a convergent plate boundary, where the African Plate is colliding with the Eurasian Plate. This collision causes the earth's crust to deform and release energy in the form of earthquakes.

Worst earthquake since 1999

In addition, sits on top of major fault lines such as the North Anatolian Fault, and is frequently shaken by earthquakes. Some 18,000 were killed in a similarly powerful earthquakes that hit northwest Turkey in 1999.

Moreover, Turkey's position at the intersection of the African, Eurasian, and Arabian tectonic plates makes it particularly vulnerable to seismic activity, with a long history of damaging earthquakes. To reduce the risk, the government of Turkey has implemented earthquake-resistant building codes and carries out regular earthquake drills, but despite these efforts, the country remains prone to earthquakes.

What are aftershocks and why do they occur?

Aftershocks are smaller earthquakes that follow a larger earthquake, or the main shock. They occur because the main shock changes the stress conditions in the Earth's crust, causing additional faults to rupture and release energy. The frequency and intensity of aftershocks decrease over time, as the Earth's crust re-adjusts to its new stress conditions.