Turkey-Syria earthquakes: Why was there so much destruction?

Turkey and Syria are reeling from the worst earthquakes to strike the region in almost a century. The initial 7.8-magnitude tremor in southeastern Turkey and northern Syria was followed by another of 7.7 magnitude.

The region straddles a number of fault lines, meaning tremors are quite common, but how often do earthquakes of this strength strike?

According to Saskia Goes, a professor of geophysics at Imperial College London, in this region events of this magnitude only occur once every hundred, or several hundred years.

“[The earthquake] is one of the largest we've recorded with instruments since we've started measuring them,” Goes told Euronews.

The last 7.8-magnitude earthquake in Turkey happened in 1939, killing around 30,000 people. More recently, more than 17,000 people died in a 7.4-magnitude earthquake near Izmit, which is over 1,000km north of the latest epicentre.

“Earthquakes are more common in the northern part of Turkey, along the northern Anatolian fault than where this earthquake happened, where they may only happen every 500 years or so,” said Goes.

She added that because of this long stretch of time between earthquakes, it’s hard to predict when one is due.

“The repeat times are so long that [...] we don't have a good record of how often they occur, which parts of the fault have already broken recently, and how the stress was redistributed.”

Shortly after the earthquakes, Turkey’s President Recep Tayyip Erdogan said that thousands of structures had collapsed. And at least another 133 buildings were brought down in northern Syria, according to the Syria Civil Defence - widely known as White Helmets - rescue service.

Since some of the buildings were more than 50 years old, they had surpassed their design life,