Two major earthquakes cause devastation across Turkey and Syria

Two major earthquakes have struck Turkey and Syria in less than 10 hours, causing widespread devastation and claiming at least 1500 lives.

A 7.8-magnitude earthquake hit close to the Turkish city of Gaziantep at 1:17 am UTC on 6 February. This was followed by a 7.5-magnitude quake around 130 kilometres north of Gaziantep at 10:24 am, according to the US Geological Survey.

The quakes have caused chaos across Turkey and Syria, burying people under collapsed buildings and damaging critical infrastructure such as roads, power lines and sewage systems.

The combined official death toll across both nations had already reached more than 1500 by midday UTC, and authorities expect it to grow rapidly over the coming days.

The earthquakes happened along the East Anatolian fault, which runs through eastern Turkey, from south-west to north-east. The first quake, which struck as people slept, caused tremors as far away as Cyprus and Egypt.

Scientists say the second tremor is likely to have been a particularly sizeable aftershock, triggered by the initial lurch in tectonic plates that caused the first earthquake. “Once it jerks in one place, it’s like a chain reaction, it starts jerking in another places,” says David Rothery at the Open University, UK.

However, there is a chance that the second quake could have been caused by the rupture of an associated fault segment stressed by the first earthquake, which would be considered a separate event.

The disaster is the most severe caused by an earthquake in Turkey since a 7.8-magnitude earthquake struck the city of Erzincan in 1939, killing 33,000 people. In a press conference, Turkish president Recep Tayyip Erdoğan said “everyone is putting their heart and soul” into rescue efforts.

Earthquakes rated as 7 to 7.9 on the moment magnitude scale are classed as major events, causing the partial or complete collapse of buildings.

International search and rescue organisations are now racing against time to deploy teams to the worst-affected areas, in order to pull people from the rubble of collapsed buildings. Those rescued within the first 24 hours have the best chance of survival, but cold weather, the civil war in Syria and the chaos caused by the two earthquakes are making swift travel to affected regions challenging, experts warn.

Poor building quality is likely to have increased the number of casualties, says Bill McGuire at University College London. “Looking at images from the cities affected, it is clear that rescuers have a massive job on their hands.”

“Many of the buildings look to have been apartment blocks that have undergone pancake collapse,” he says. “This occurs when the floors and walls are not tied together well enough, so that each storey collapses vertically down into those below, leaving a stack of concrete layers like a pack of cards, within which there are few spaces where people can survive.”

Organising water, food and shelter for those displaced by the earthquakes must also be a priority, particularly with local temperatures forecast to drop below –4°C (25°F) overnight this week, says Ilan Kelman, also at University College London. “There may be severe deaths from hypothermia and other weather-related conditions.”

It is notoriously difficult for seismologists to give advance warnings of earthquakes, so constructing earthquake-resilient buildings and infrastructure is widely seen as the best defence against a major disaster.

Since 2004, all construction in Turkey has been legally obligated to follow modern earthquake-proof standards, but both Syria and Turkey have thousands of buildings that aren’t designed to withstand major seismic activity, despite being in a region of high earthquake risk.

“This earthquake was survivable,” says Kelman. “If infrastructure had been built correctly, this would have been a major earthquake, but not an earthquake disaster.”