Terrible earthquake in Turkey, which claimed the lives of thousands of people and destroyed a huge number of houses, made the whole world shudder and wonder why this is happening. The earthquake also raised the question of the reliability of our homes.
The site TSN.ua asked Do earthquakes threaten Kyiv and how can houses be protected from destruction?.
At the Institute of Geophysics we were assured that earthquakes of this magnitude do not threaten Ukraine, but the seismic danger still exists.
“The danger for Ukraine is not as great as, for example, for Turkey, or other countries covered by a powerful seismically active belt of our planet. It was formed due to the fact that Eurasia seems to be descending from top to bottom, and the African and Indian continental plates are moving towards it. Obviously, when they met many millions of years ago, huge tensions arose that continue to accumulate even now, ”says the TSN.ua website. Oleksandr Kendzera, Director of the Institute of Geophysics of the National Academy of Sciences of Ukraine.
He adds that when the tensile strength of a material is exceeded, then earthquakes appear.
“It is currently impossible to say exactly when enough energy will be accumulated for an earthquake to occur, but it is possible to estimate what size blocks are involved in the formation of a stress-strain field. And by the size of these plates, on which energy is accumulated, it is possible to estimate what maximum earthquake can occur in one place or another. The earth has long been in a state of dynamic deformation. We see that new faults appear all the time, where energy disappears and dissipates in space, and where it breaks out and accumulates to such a level that earthquakes can occur, ”explains the specialist.
What threatens Kyiv
The territory of Ukraine is located near this powerful seismically active belt, stretching across the Mediterranean Sea, the Caucasus, Idokush, and then blurs into two separate belts. Ukraine is less likely that strong earthquakes can occur frequently, but countries such as Georgia, Armenia, Cyprus, Turkey, Syria are geographically located in the zone where earthquakes can occur more often.
“For Kyiv, we have historical data for almost a thousand years on how earthquakes were felt on its territory. It cannot be said that Kyiv is threatened by earthquakes of such magnitude as in Turkey. But there are others that can be dangerous. In particular, earthquakes occurring in part of the Vrancea zone in Romania. The sources of these earthquakes are formed at a very great depth – about 140-180 km. They are very strong. In terms of strength – even more than those held in Turkey. Since these earthquakes have a deep focus, seismic waves slowly fade and reach Kyiv, Moscow and St. Petersburg quite intensively, leaving cracks and destruction, and if seismic waves get into resonance, then there can be great destruction,” says Alexander Kendzera .
Photo: UNIAN
What to do in case of an earthquake
The expert says that you need to prepare for an earthquake in advance. For example, do not put large things on top of the cabinet so that they do not fall. Know the phones to quickly call emergency services that can help after the destruction of the house.
«People need to know if their house is earthquake resistant or not. This information can be provided by seismologists and maintenance specialists who have experience in which houses are better able to withstand earthquakes. When it comes to the earthquake itself, there are several rules of conduct. It is recommended to leave the house during an earthquake, but on the other hand, if you leave a house that has huge glazed surfaces, then in this case there is a danger that when such surfaces are destroyed, huge pieces of glass will fall at great speed and can injure or even kill a person. Therefore, people need to make the best decision – to stay in the house or evacuate. If you stay, then you need to move away from the windows, stand at the load-bearing walls, if the house is not high-rise, then it is better to run out into the street, ”explains the expert.
People living in seismically active areas are given leaflets that describe how to act in an earthquake. They recommend:
- hide under tables rather than run out into the street;
- do not panic;
- try not to use elevators, they are often jammed during an earthquake.
How to protect houses?
The specialist says that there are few ways to protect yourself from earthquakes, but they exist.
“One should be attentive to information about a possible oscillation of the earth’s crust. This should be taken into account when designing houses or those already built. This information can be obtained through observations of real seismic waves using special sensors. In this case, we can foresee the stress that will occur in the designed house. We can strengthen the structure of the building in this particular place in advance or even change the building model itself. Then there will be no danger, ”the specialist says.
Didn’t learn the lesson from the past
The earthquakes that occurred in Turkey and Syria are another problem. The houses just fell apart.
“Obviously, this happened due to insufficient work to ensure the seismic resistance of houses. And this had to be done. Unfortunately, all of Turkey belongs to a seismically active zone – somewhere more, somewhere less, but throughout its entire territory it is necessary to take into account the seismological hazard. They obviously took a different path there, deciding to build cheap houses, which they can and will build, because earthquakes do not happen so often in Turkey, ”says the scientist.
By the way, the last strong earthquake that claimed thousands of human lives occurred in Turkey in 1999, in the city of Izmit in the northwestern part, 90 kilometers from Istanbul. Previously, powerful earthquakes were recorded mainly in the southeast of Turkey.
“Most likely, not everyone in Turkey learned the lesson of the Izmit earthquake if they allowed to build cheap housing. A huge number of houses were destroyed precisely because they were not earthquake-resistant, or could be quasi-seismic-resistant – that is, they were designed for heavy loads, but were not calculated for real shaking that could be in this dangerous zone, ”says Alexander Kendzera .
It is necessary to study the seismic effect on new buildings
The specialist says that it is very good to trace the features of the seismic impact on historical buildings. For example, the ancient Turkish fortress of Gaziantep, which is over 2200 years old and has never suffered from earthquakes. And yesterday it was completely destroyed by the push. This suggests that in a particular place there were conditions for the occurrence of strong earthquakes.
“The fortress in this area has experienced only superficial earthquakes in 2200 years. They were fast and the intensity of their seismic effects is small. There is a method called detailed seismic zoning, it allows you to determine what earthquakes may be in the future from the nearest seismically active belts or faults. That is, it could have been foreseen and strengthened the fortress with retaining walls and preserved the UNESCO World Heritage Site,” Alexander Kendzera concludes.
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