MOSCOW, July 13, Tatyana Pichugina.In winter, a powerful earthquake occurred in Turkey. Tens of thousands of people died. Scientists warned about this: there is a zone of active tectonic faults. According to them, the catastrophe could happen again in the area of the Sea of Marmara, on the shores of which Istanbul stands. In this case, a tsunami is not ruled out.
The forecast is waiting in the wings
The 1999 earthquake of magnitude 7.4 with its epicenter in the Izmit Gulf of the Sea of Marmara, 80 kilometers from the Turkish capital claimed over 17,000 lives. An analysis of what happened showed that the next destructive event should be expected here in 25 years — in the 2020-30s.
The prediction came true, but in a different place: on February 6, 2023, with a difference of nine hours in the southeast of the country, there were two strong tremors of 7.8 and 7.5 points. Followed by thousands of small aftershocks. Almost 60 thousand people died in Turkey and Syria, and tens of thousands more were under the rubble. This has not happened in Asia Minor for almost eight centuries.
Türkiye is seismic, it is well known. There is a junction of lithospheric plates, and between them, in the earth's crust, there are faults. Two large ones — in the north and southeast of the country — North Anatolian (SAR, it is in its western part that Istanbul is located) and East Anatolian (crosses the province of Kahramanmarash, which suffered so much this winter). There were 13 earthquakes in Turkey in the 20th century. -crop-width=»600″ data-crop-height=»400″ data-source-sid=»rian_collage» class=»lazyload» width=»1920″ height=»1280″ decoding=»async» />
Both faults are in constant motion — sometimes slow, sometimes sharp, which is often accompanied by tremors. Scientists call such structures in the earth's crust «living». They are studied by various geomorphological and geophysical methods, including from satellites and using GPS systems, in which the accuracy reaches millimeters.
Measurements of the horizontal movements of the SAR showed that to the south of it, rock masses move at a speed of 16-19 millimeters per year, and to the north, along the Black Sea coast, they move an order of magnitude slower or do not move at all. As a result, the restless southern side «ran away» from the stable northern side by several meters. Huge tension has accumulated in the bowels of the earth. So, we need to wait for an earthquake of magnitude more than seven in the Sea of Marmara, which will also affect Istanbul. This forecast was first published in 2016. And it has not yet come true.
Scientists remind of a possible catastrophe
The other day, a member of the Council of Scientists of the Istanbul City Hall on Earthquakes, Naci Görura, reminded of the danger. According to him, a new forecast was made based on a study of the history of the region's seismicity over two thousand years and an analysis of geophysical data. Göryur's colleague Haluk Eyidogan clarified that the probability of a catastrophe in the Sea of Marmara by 2030 is 50 percent.
Experts emphasize that their goal is not to scare the population, but to warn the authorities so that they can take measures in advance. «People tend to forget everything quickly,» said Eyidogan.
The scientists presented various scenarios for the development of events, risk assessments and destruction to the Istanbul City Hall. According to calculations, in the metropolis, an earthquake of magnitude 7.5 will collapse about 90,000 buildings. The authorities plan to build reserve cities in low-seismic areas to resettle the victims. However, the catastrophe will immediately affect seven provinces of Turkey, where 25 million people live. The consequences will be very serious.
What if it comes tsunami
Earth tremors in the Sea of Marmara will cause a tsunami. Russian scientists, together with colleagues from Turkey, modeled it back in 2016 as part of the international European project ASTARTE. For example, they took the Haydarpasa district in the south of the Asian part of Istanbul — there is a large container port.
We built maps of the seabed and coast with details up to one meter. According to calculations, the head wave will reach Haydarpasha in five minutes. This means that there is no time for notification and evacuation.
With a maximum wave height of 4.5-6 meters and a speed of six meters per second, a coastal zone 340 meters wide in the southeastern part of the port will be under water. It could be worse — due to the surge of water by the wind or fluctuations in atmospheric pressure.
Breakwaters will not save — the wave rushes parallel to them, sweeping away embankments. Large ships will be washed ashore, and this will cause great destruction. After all, a lot of goods are stored there, and the place itself is very urbanized.
The document sent to the Istanbul City Hall takes into account the tsunami, Haluk Eyidogan clarified in a comment for. According to him, evacuation plans for this case are posted on the streets of the metropolis. The risks of flooding of all 39 districts have been worked out. A wave with a height of four to eight meters is capable of moving one and a half kilometers from the coast, primarily into lowlands, for example, in the Küçükçekmece area in the west of the city. Yenikapı, Ataköy and Buyukcekmece on the European side will suffer the most.