The Daily Mail: Türkiye has moved in after the devastating earthquake
The massive tremors that hit Türkiye on Monday have shifted the tectonic plates they sit on by up to 10 feet (3 Meters), according to geology experts.
Türkiye is located on major fault lines that border the Anatolian Plate, the Arabian Plate and the Eurasian Plate, and is therefore vulnerable to seismic activity.
Meteorologists revealed a rupture occurred in a 140-mile (225 km) stretch of rift between the Anatolian Plate and the Arabian Plate.
As a result, Türkiye could have slipped as much as 5 to 6 Meters towards Syria, according to Italian seismologist Dr. Carlo Doglione.
However, he added that this was all based on preliminary data, and more accurate information from satellites will be available in the coming days.
Dr. Bob Holdsworth, professor of structural geology at Durham University, said the shifting of the plates was completely understandable given the magnitude and strength of the quake.
Dr. Holdsworth added, “There’s a fairly predictable and widely documented relationship between earthquake magnitude and the typical displacement that occurs… As a general rule, an event of magnitude 6.5 to 6.9 is associated with displacements of about 1 Meter, while the largest known earthquakes can involve displacements of 10 to 15 Meters.
The slip faults in Türkiye are horizontal slip faults that mainly involve horizontal displacements, therefore the total compensations in the region of 3 to 6 Meters proposed here are quite reasonable.
Horizontal displacements of this kind can sever key subsurface and surface infrastructure, including water pipes, power cables, gas pipelines, and tunnels.
There may also be surface fissures that develop where the cracks break away to the surface, they can offset roads, rivers and other features, including built structures.
Catastrophic earthquakes occur when two tectonic plates sliding slowly in opposite directions meet and then suddenly slide violently.
These two plates consist of the Earth’s crust and the upper part of the Earth’s core, or mantle, while below is the asthenosphere, the loose, viscous, warm conveyor belt of rock that tectonic plates ride on.
They don’t all move in the same direction and often collide, building up a great deal of pressure between the two plates that must be released.
In the end, this pressure causes one of the plates to vibrate either under subduction, which is called subduction, or over the other, which can be called collision and riding, with partial subduction sometimes.
This releases a huge amount of energy, causing tremors and destroying any nearby property or infrastructure.
Intense earthquakes usually occur over fault lines where tectonic plates meet, but minor tremors can occur in the middle of these plates, at the continental shields.
Türkiye is close to the intersection of three tectonic plates, which means it is prone to earthquakes.
“Aleppo (Syria) and Gaziantep (Türkiye) regions have experienced a series of devastating earthquakes historically and an event of similar magnitude occurred about two centuries ago,” Dr Anastasios Sixtus, professor of earthquake engineering at the University of Bristol said.
The majority of Türkiye’s land lies on the Anatolian Plate, which is compressed between three other large plates.
And to the north of the plate is the Eurasian plate, to the south is the African plate, and to the east is the Arabian plate.
This creates two large fault lines – East Anatolia and North Anatolia – both of which are prone to seismic activity.
This is because the Arabian plate pushes north towards the Eurasian plate, and presses the Anatolian plate westward towards the Aegean Sea.
The earthquakes, starting Monday, occurred on the southwestern end of the 434-mile (699 km) East Anatolia fault line.
The first earthquake with a magnitude of 7.8 occurred at a depth of about 11 miles (18 km), while the second quake occurred nine hours later at a depth of six miles (10 km) and a magnitude of 7.5 on the Richter scale.
Dr Joanna Walker, Professor of Earthquake Geology and Disaster Risk Reduction at University College London (UCL), said that these two earthquakes belong to slip earthquakes that is, caused by displacement faults.
This is where two land masses move horizontally along the fault plane as a result of the horizontal pressure build-up.
Dr. Walker said, “Slip faults are of medium strength, so they can host earthquakes of magnitude 7 or 8… The size depends on the slip and the length of the ruptured crack… So for a fault system with a total length of 690 km, such large magnitude earthquakes are possible”.
Eastern Anatolia has an average slippage of between 0.2 and 0.4 inches (6 and 10 mm) per year near eastern Türkiye.
However, data reported by meteorologist Matthew Capucci of MyRadar Weather shows that this week’s earthquakes caused the Anatolian Plate to slide up to 10 feet (3 Meters).
Doglione added that more data from the European agency’s Sentinel and ASI CosmoSkymed satellites will provide more information in the next few days.
According to Dr. David Rothery, a geoscientist at The Open University, Türkiye is moving about 0.8 inches westward per year along the East Anatolia Rift.
“Because of the friction along the fault lines, the movement is not smooth,” he said.
Instead, the energy builds up locally over years or decades until the accumulated stress is strong enough to overcome the resistance between the two slip surfaces and blocks of rock crash into each other in a sudden jerk… In this case, the violence of the shaking on the surface was strong enough to collapse buildings, which is likely the reason why most human lives were lost… There may have been landslides also in the mountainous terrain”.
To date, more than 5,100 deaths have been confirmed in Türkiye and Syria, and dozens are trapped in the rubble of their demolished homes.
After the two major earthquakes on Monday, another 5.8-magnitude quake hit the area on Tuesday morning as rescue efforts continued to rescue the trapped survivors.
Although the tremor wasn’t as strong as the first two, it was recorded at a shallow depth of 1.2 miles (1.9 km), which means it could cause more damage.
A winter storm and freezing temperatures have held back those working in a race against time to free people from the rubble, as the cold weather makes the need to reach trapped survivors even more urgent.
The World Health Organization warned on Monday that the death toll could reach 20,000, and said on Tuesday that 23 million people, including 1.4 million children could be affected.