A magnitude 7.8 earthquake struck southern Turkey, killing at least 2,600 people. Human casualties continue to rise.
The reasons that increased the damage of this earthquake are that the depth to the epicenter is shallow at 18 km, that energy has been accumulated since no major earthquake has occurred in the area for nearly 200 years, and that most buildings have been weakened due to the civil war in Syria that has continued for more than 10 years. One point is that it occurred at dawn, making it difficult to evacuate.
On this day, a strong earthquake with a magnitude of 7.8 occurred at 4:17 a.m. local time (10:17 a.m. Korean time) in the southeastern Gaziantep and south-central Kahramanmaras regions of Turkiye, adjacent to the Syrian border. After that, at 1:24 pm local time, a 7.5 magnitude aftershock occurred 59 km north-northeast of Turkiye Kahramanmaras. The depth of the epicenter is 10 km.
According to Turkiye and Syrian authorities, the total number of deaths on this day is more than 2,600. At least 1,651 people were killed in Turkey and at least 1,000 in Syria.
At least 2,834 buildings were destroyed in the earthquake, and 120 aftershocks occurred in the Kahramanmaras province.
◇Cracked ground moving horizontally… There has been no earthquake in nearly 200 years, and energy is increasing
The appearance of a strike-slip fault (strike-slip fault). A striking fault is a fault in which the upper and lower halves move horizontally along the fault plane, and even in the case of an earthquake of the same magnitude, the damage can be much greater if the fault is a reverse fault or a positive fault in which the fault moves vertically (captured from the US Geological Survey website).Turkiye is one of the most seismically active regions in the world. It is located at the junction of the Anatolian plate, the Eurasian plate, the Arabian plate, and the African plate. The earthquake was caused by the Arabian plate moving north and colliding with the Anatolian plate.
In particular, the region where this earthquake occurred is located on the East Anatolia Fault, which is a typical strike-slip fault. A strike fault is a fault in which the upper and lower halves of the fault move horizontally along the fault plane, and even if an earthquake of the same magnitude occurs, the damage can be much greater if the fault is a reverse fault or a positive fault in which the fault moves vertically.
“The ground shaking would have been more severe than an earthquake with the same magnitude and deeper epicenter,” planetary geoscientist David Laurie of The Open University in the UK told Reuters.
The fact that the depth of the epicenter was relatively shallow also increased the damage. Professor Chris Elders, from Curtin University’s School of Earth and Planetary Sciences in Australia, said: “It would sound very deep, but the energy released by the earthquake would have been felt very close to the surface with much greater intensity than it would have been deep in the crust.”
The magnitude 7.8 earthquake that occurred in Nepal in 2015 was also close to the surface at an epicenter depth of 11 km. At that time, the earthquake claimed about 9,000 lives.
Although it is an earthquake-prone region, the East Anatolia fault where this earthquake occurred has been relatively quiet with no recent seismic activity. It means that you have accumulated a lot of energy.
“The East Anatolia Fault hasn’t had a magnitude 7 earthquake in more than 200 years,” Roger Merson, an honorary research fellow at the British Geological Survey, told AFP. “This could mean people are overlooking how dangerous earthquakes can be.”
In particular, Merson compared this earthquake with a magnitude 7.4 earthquake that occurred in the same area on August 13, 1822. At that time, about 20,000 people died in this earthquake. “It’s been so long since the last earthquake that it could have built up quite a lot of energy,” he stressed.
“Compared to a magnitude 6.2 earthquake that struck central Italy in 2016 and killed 300 people, this earthquake released 250 times as much energy,” Joanna Faure Walker, director of the Institute for Risk and Disaster Reduction at University College London, told Reuters.
◇Due to the civil war, buildings are worn out and refugees suffer a lot… Aftershocks continue, rescue difficulties in cold weather
The fact that the earthquake-resistant design was not appropriate was also pointed out as a background for the large-scale loss of life. “Unfortunately, seismic infrastructure is patchy in southern Turkey and Syria,” volcanologist Carmen Solana of the University of Portsmouth in the UK told the BBC.
Bill Maguire, a volcanologist at University College London, said: “In Syria, many structures have already been weakened by more than a decade of war.”
Refugees fleeing the civil war are staying in northern Syria, which borders Turkey. The buildings are old and it is a vulnerable area in the event of an earthquake.
As aftershocks continue, there is a risk that the scale of human casualties will increase. “What we’re seeing now (the aftershocks) is spreading to neighboring faults,” Merson said. “We expect the earthquake to continue for a while.” Even at the time of the 1822 earthquake, aftershocks continued into the following year.
Professor Elders told Al Jazeera that aftershocks also occurred about 100 to 200 km away along the large fault line.
There are also observations that the number of victims from this earthquake will exceed 10,000. Catherine Smallwood, World Health Organization (WHO) European emergency officer, said: “We often see an eight-fold increase in the number of deaths from the initial figure due to the possibility of further collapse. ” he told AFP.
Rescue work is also difficult because of the cold weather. Currently, the highest midday temperature around the epicenter is 3-4 degrees. The temperature is expected to drop further in the future and is expected to hover below freezing until the morning of the 7th.
“Right now, besides bad weather, collapsed buildings and damaged hospitals, we have a crisis,” Mazen Kiwara, director of the Middle East for the American Medical Association in Syria (SAMS), told Al Jazeera.
Researcher Merson also said, “Cold weather reduces the chances of survival for those trapped in the wreckage,” and “there could be thousands or tens of thousands of victims.”
Source: Donga
Mark Jones is a world traveler and journalist for News Rebeat. With a curious mind and a love of adventure, Mark brings a unique perspective to the latest global events and provides in-depth and thought-provoking coverage of the world at large.