Murderer earthquake magnitude 7.8 hitting the southeast Turkey and parts of Syria in the early hours of Monday, February 6, resulted in at least 5,000 deaths and thousands more injured. About nine hours later, another large 7.5 magnitude earthquake followed, as well as another 200 aftershocks.

Earthquakes have collapsed thousands of buildings, rescuers are searching for survivors in the rubble, and the death toll is expected to rise. Nature magazine spoke to four researchers about seismic activity in the area and what’s expected in the coming days.

Turkey is an active seismic zone.

Most of Turkey lies on the Anatolian tectonic plate between two major faults: Northern Anatolia and Eastern Anatolia. The Arabian tectonic plate, which includes Syria, is moving north and colliding with the southern edge of Eurasia, which is “pressing” Turkey to the west, said David Rothery, a geologist at the Open University at Milton, Kings in Britain.

“Turkey is moving west at a rate of about two centimeters a year along the eastern Anatolian fault,” he adds. “Half the length of this fault is now seismically active.”

Seyhun Puskulcu, a seismologist and coordinator for the Istanbul-based Turkish Earthquake Foundation, says people in Turkey are well aware of how vulnerable they are to earthquakes. “It was not a surprise at all,” says Puskultsov, who runs earthquake awareness seminars.

The war affected the already vulnerable buildings

Earthquake deaths are often caused by falling bricks and stones. According to the US Geological Survey, many people in Turkey affected by the earthquake live in buildings made of poor quality concrete and with little reinforcement, which are highly likely to be affected by earthquakes.

In a study published last March, Arzu Arslan Kelam of the Middle East Technical University in Ankara and her colleagues argue that Gaziantep city center will suffer moderate to severe damage from a magnitude 6 earthquake.5 Richter. This is due to the fact that most of the existing buildings are low brick structures and are built very close to each other.

In 1999, a magnitude 7.4 earthquake struck 11 kilometers southeast of Izmit, Turkey, killing 17,000 people and leaving more than 250,000 homeless. After this tragedy, the Turkish government introduced new building codes and regulations, as well as a mandatory earthquake insurance system. However, many of the buildings hit by Monday’s quake were built before 2000, says Mustafa Erdik, a civil engineer at Turkey’s Bogazici University.

Things are even worse in Syria, where more than 11 years of fighting have made it impossible to check building codes. The earthquake hit the northwestern regions of Syria and collapsed buildings in Aleppo and Idlib. Some of the war-damaged buildings have been rebuilt using low-quality materials or “whatever materials are available,” says Rothery.

“Perhaps destroying them would be an easier task than if a little more money had been spent on their construction. We haven’t installed it yet,” he adds.

What is expected next?

Researchers say the world should prepare for more earthquakes and aftershocks, as well as worsening weather. “The possibility of strong aftershocks causing even more damage will persist for weeks or even months,” says Ilan Kelman of University College London.

“Weather forecast in this area shows that the temperature will drop below zero. This means that people who are trapped among the rubble and who could be rescued are at risk of dying from the cold,” he emphasizes.

The epicenter of the main earthquake was located 26 km east of the city of Nurdaghi in the province of Gaziantep, Turkey, with a focal depth of 17.9 km. The second earthquake of magnitude 7.5 struck about four kilometers southeast of Ekinoso in the province of Kahramanmaras.

^{Source: Nature}