The new tremors in Turkey and Syria that occurred on February 20 were abnormally strong and are an “unpleasant symptom” that seismic activity in this region will be long, scientists told Izvestia. And in danger, in their opinion, are other countries located in seismic zones of the Mediterranean – Italy, Greece, Cyprus, Spain, Portugal. Unusually long underground activity is due to the fact that in coastal zones the movement of lithospheric plates occurs more often and is felt stronger than on the mainland. The researchers also note that the earthquake could have been triggered by the closest approach of the Moon and Earth in 992 years, which occurred on January 21. It caused an additional displacement of the plates, which led to a series of strong tremors.
Dangerous breakdown
Events in Turkey and Syria are not developing quite according to the scenario that most scientists predicted. After a large earthquake with a magnitude of 7.7, which happened on February 6, seismologists said that the tremors would continue for some time, but their strength would noticeably decrease. Despite this, on February 20, new earthquakes of magnitude 6.4 and 5.8 occurred on the border of the two countries. Experts from the European Mediterranean Seismological Center reported that this was the ninth strong earthquake in the region over the past three days. And in just two weeks since February 6, about 6 thousand tremors have been recorded in Turkey and Syria.
Photo: REUTERS/Maxim Shemetov
“The last push was really anomalously strong, and this is an unpleasant symptom,” Vladimir Troyan, professor at the Department of Earth Physics at St. Petersburg State University, told Izvestia. “Before that, there was a trend towards a decrease in the intensity of aftershocks. Now in this region they are likely to continue. Notable tremors are not ruled out in seismic zones near Turkey – this applies to Italy, Greece, Cyprus, Spain, Portugal and other countries associated with the Mediterranean region. In other parts of the world, a catastrophic earthquake is not expected.
In the source zone of the last earthquake, which stretches for several hundred kilometers, there will certainly be other tangible shocks, said Ruben Tatevosyan, deputy director of the Institute of Physics of the Earth RAS for engineering seismology and seismic hazard assessment, head of the laboratory of strong earthquakes and seismometry.
“The events of February 20 took place in the same zone as the events of February 6,” the specialist noted. – A strong earthquake is accompanied by subsequent shocks, which are determined by the magnitude of the main shock. If it was large, then the series lasts longer and there are more powerful shocks in it. In the case of this impact, which is extraordinary in its magnitude of 7.8, they can last for months.
Photo: REUTERS/Nir Elias
Earth, Moon and Gravity
In coastal zones, underground activity is higher than in continental areas. This is due to the structure of the earth. At its center is an inner core with a radius of about 1250 km, followed by an outer core with a thickness of about 2200 km. Above it lies 2900 km of viscous mantle, and even higher – a fairly hard crust about 40 km thick.
“Clumps rise from the liquid part of the core from time to time, which arise in connection with the reactions taking place there,” explained Vladimir Babeshko, director of the Research Center for Forecasting and Prevention of Geoecological and Technogenic Disasters of KubSU. “They go up because they are lighter and go out through the volcanoes. To compensate for the pressure, something must be pulled into the Earth’s crust. Oceanic lithospheric plates are most suitable for this, since they are much softer than continental ones. Turkey is located in the coastal zone, which is probably why the recent earthquake is so strong and lasts so long.
Photo: Global Look Press/NASA
Scientists have a theory that earthquakes can be triggered by the distance from the Earth to the Moon. On January 21, the Moon was closest to the Earth in the last 992 years, the distance to it was 356,568 km. The gravity of the moon is closely related to tidal processes, and they, in turn, could cause a shift in tectonic plates.
– It is possible that the proximity of the satellite to our planet was the very last straw, – says Vladimir Troyan. – The tension of the rocks was already strong, but the moon could become a kind of trigger.
Experts note that, despite the available technology and the ability to calculate, it is still impossible to predict the dates and strength of further earthquakes. Although large-scale work in this direction is being carried out, their catastrophicity, as the events of the past two weeks have clearly shown, is incredibly high.
Photo: Global Look Press/imagebroker/Anton Luhr
“Artificial intelligence technologies, including machine learning algorithms, computing resources of supercomputers, as well as the ability to store and work with much larger amounts of data, can create the conditions for a breakthrough in this area by simulating earthquakes and modeling,” said an expert from the NTI Competence Center based at Moscow State Technical University named after . N.E. Bauman Dmitry Evsyukov. “These approaches make it possible to obtain huge arrays of measurements, and then filter them to search for patterns that reliably signal when an “artificial” earthquake occurs. Hypotheses are confirmed by superimposing digital twins of earthquakes on seismic data from real recorded shocks.
According to the latest data, the death toll from the earthquake in Turkey, which occurred on February 6, has reached 41,156 people, more than 5,800 people died in Syria. The aftershocks on February 20 in Turkey and Syria killed at least 6 people, more than 730 were injured. The World Health Organization estimates that 23 million people have been affected by the disaster in one way or another.
