Since early on Monday, Turkey has been hit hard by a string of significant earthquakes, with the first one, a 7.8-magnitude tremor, being characterised as the country’s largest in more than a century.
Turkey Earthquake_According to data on the United States Geological Survey (USGS) website, at least 41 more earthquakes with a magnitude of 4 or higher have been reported in the same region southeastern Turkey near the borders with Syria over the course of the last 12 hours. One of these subsequent earthquakes had a magnitude of 7.5, making it as powerful as the initial one.
The tremors have severely impacted Turkey and Syria, and as of Monday night, news organisations have reported the deaths of at least 1,700 people in both countries. Turkey is where more than a thousand of these casualties have been recorded.
Aftershocks are likely to last for a few days or perhaps weeks, as is typical for large earthquakes.
Based in an earthquake prone area are Turkey and Syria
The Turkey earthquake’s epicentre is located in the Anatolia tectonic block, a well-known seismic fault line that spans through northern, central, and eastern Turkey.
It is a seismically active area, albeit not as active as, for example, the Himalayan region, which is one of the most earthquake-prone locations in the world.
Recent years have not seen a lot of large earthquakes, particularly those of magnitude 5 or greater. Only three earthquakes of a magnitude of 6 or higher have been recorded in the area since 1970, according to USGS. In this region, a significant earthquake occurred in January 2020.
The interactions between the African, Eurasian, and Arabian plates are what cause the seismic activity in this area. It is known that the Arabian plate is pushing northward, which causes the Anatolian plate, on which Turkey is situated, to shift slightly westward.
According to the USGS, the Turkey earthquake on Monday occurred at a nearly vertical fault line on the eastern Anatolian block, not far from the Syrian border.
“The earthquake’s mechanism and epicentre are compatible with it having taken place on either the Dead Sea transform fault zone or the East Anatolia fault zone. While the Dead Sea Transform facilitates the Arabian peninsula’s migration to the north in relation to the African and Eurasia plates, the East Anatolia fault accommodates Turkey’s westward extrusion into the Aegean Sea.
Deeper Turkey earthquakes are far more damaging.
The fact that Monday’s earthquakes originated from such shallow depths made them so deadly. The first Turkey earthquake, which had a magnitude of 7.8, began 17.9 km beneath the surface of the planet. The 7.5 magnitude one and all those that followed came from even closer to the surface.
Because they release more energy when they hit the surface, shallow earthquakes are typically more destructive.
When deeper earthquakes reach the surface, they have lost a lot of their energy. Even while the deeper earthquakes travel further and lose energy as they do so, they nonetheless do less damage since the seismic waves migrate conically upward to the surface.
For instance, the earthquake that struck Nepal two weeks ago and whose aftershocks were felt over much of northern India began around 25 km below the surface of the planet. Although one woman was reportedly killed by a stone that fell from a hill as a result of the earthquakes, it did not result in extensive damage.
The magnitude of an earthquake is another determinant of its destructiveness, and the Nepal earthquake had a low magnitude of 5.8.
Accordingly, the 7.8 magnitude Turkey earthquake that struck on Monday was 1,024 (32 × 32) times more strong than the 5.8 magnitude earthquake in Nepal and created waves that were 100 times as large. In general, energy changes by around 1.4 times for every 0.1 variation in magnitude.
The most frequent natural hazard that cannot be forecast is still earthquakes. As a result, there can be no early warning systems created.
The lead time between the moment of the earthquake’s inception and when it reaches the Earth’s surface may theoretically be a few seconds. Seismic waves move between 5 to 13 km/s, which is far slower than the speed of light. Therefore, information regarding an earthquake may be transmitted a few seconds before it touches the ground if it is identified as soon as it is caused.
These technologies are already in use in certain places to send out earthquake notifications. These are not forecasts, though. After the occurrence, the notifications are sent out.
The search for trustworthy earthquake forecasters hasn’t been very successful so far. There is no way to forecast when an earthquake will occur, but scientists have been able to map the regions that are earthquake prone and are likely to produce earthquakes in the future.
For instance, according to geologists, the Himalayan area has accumulated so much tension below the surface that it might cause several earthquakes with a magnitude of 7 or 8. But the exact timing of that cannot be foreseen.
On average, one to three earthquakes with a magnitude of 8 or higher are reported year, while 15 to 20 earthquakes with a magnitude of 7 to 8 take place.