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Turkey was hit hard by the earthquake. And we often hear that this is the case because Turkey straddles several tectonic fault lines.
What is a tectonic fault? And what does it have to do with earthquakes? The BBC spoke to a seismologist to find out.
“Tectonic plates move at the same speed as the growth of a human fingernail.”
Dr Jessica Hawthorne describes about 16 large tectonic plates around the world that make up the outermost layer of the Earth’s crust.
Associate Professor of the Department of Earth Sciences at the University of Oxford. study the mechanism of earthquakes and explains that it is related to tectonic plate faults
“A tectonic fault is the point at which two tectonic plates cross…”
Although the two tectonic plates move towards each other relatively slowly. (Usually about 2-3 centimeters per year), but sudden movement or sliding quickly. It could release so much energy that the rocks would crack and cause earthquakes.
Dr Hawthorne explained that such cases often occur near the surface of the earth. Because the hotter rocks near the Earth’s core melt.
More than 80% of major earthquakes occur along the Pacific Ocean, known as the “Ring of Fire,” where the Pacific Plate is pushed down by the surrounding tectonic plates. lower
Types of tectonic faults
Dr Hawthorne said that while earthquakes produce new tectonic plates, most cases are caused by existing faults.
The slippage of tectonic plates is often caused by existing faults. These faults can be classified into three main types: normal fault, reverse fault, and strike-slip fault.
horizontal fault
This type of fault occurs when tectonic plates cross horizontally. That is, move sideways. not up or down
An example of this type of fault is The East Anatolian Fault, 700 km long, runs along the boundary of the Anatolian Plate. and the Arabian tectonic plate in Turkey.
The magnitude 7.5 and 7.8 earthquakes that rocked Turkey and Syria on Feb. 6 were the strongest in nearly a century in the region. and is moving horizontally
In addition, earthquakes and aftershocks occur at shallow locations. is only a few kilometers below the ground This was one of the reasons why the tremor caused such great damage. and killed more than 35,000 people.
Another example of a similar tectonic fault is The San Andreas fault in California, USA, formed by the shift between the Pacific Plate in the west and the North American Plate in the east.
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The Great San Andreas Fault earthquake in 1906 severely damaged San Francisco.
According to the US Geological Survey, the Great Earthquake in California on April 18, 1906 was caused by the fracture of the northernmost lands of the San Andreas Fault. Severe damage to the city of San Francisco. It was one of the deadliest earthquakes in the history of the world.”
normal fault
This type of fault is the separation of the land. The land part will move down vertically.
in the Afar region of Ethiopia It is the point of confluence of three tectonic plates called the Afar Triple Junction, including the African tectonic plate. Arabian Tectonic Plate and the Somalia tectonic plate which creates a Y-shaped split line
The movement of the earth’s crust in this area causes stress. Until becoming faults, volcanoes and other geological changes
In 2005, a rupture in this area caused an earthquake. There was a spout of ashes. Also, a fissure was 8 meters deep and 60 km long.
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Volcanic eruptions in Iceland are the result of the movement of tectonic plates.
As the North American and Eurasian tectonic plates move apart, the “Mid-Atlantic Ridge” is formed, a line of undersea mountain ranges at the junction of the two plates. Extends thousands of kilometers between the north and south Atlantic Ocean.
This phenomenon causes a series of undersea mountain ranges to rise above the surface of islands such as Iceland and Ascension Island in the Atlantic Ocean.
It also causes tectonic plate faults, earthquakes and volcanic eruptions.
reverse fault
This type of fault occurs when two tectonic plates meet. and a land was pressed down below
Dr Hawthorne said these faults usually occur at tectonic plate boundaries. and is often a large fault Because they often cut through the land at an angle that creates wide rifts that cause tectonics.
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An earthquake off the coast of Japan in 2011 caused a devastating tsunami.
The Japan Trench is an undersea tectonic plate fault area that extends from north to south. on the east coast of the Japanese archipelago Dividing the Eurasian Plate and the Pacific Plate
After the 9.1-magnitude Tohoku earthquake off Japan’s east coast in March 2011, the fault displaced 50 meters, causing a tsunami that caused serious damage to lives and property. live along the coast of Japan Including causing a disaster at the Fukushima nuclear power plant.
Peru-Chile Trench (Peru-Chile Trench), also known as The Atacama Trench is located on the eastern coast of the Pacific Ocean. It lies about 160 km off the coast of Peru and Chile, between the Nazca and South American tectonic plates.
The penetration of the Nazka tectonic plate beneath the South American continental plate caused intense tectonic activity.
On May 22, 1960, a 9.5 magnitude earthquake near Valdivia. southern chile It was the largest earthquake in the world ever measured.
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Scientists estimate that The energy released is 20,000 times more powerful than the atomic bomb dropped on Hiroshima during World War II.
However, Dr Hawthorne said that living near
Tectonic plate faults are not always a concern. Because not all tectonic faults cause earthquakes.