yesterday’s earthquake in Gaziantep Turkey Magnitude 7.8 is the strongest in the Eastern Mediterranean in the last 100 years. About nine hours later, a second earthquake of magnitude 7.5 followed, which has not yet been determined whether this is an aftershock or a new earthquake. Both earthquakes occurred at a shallow source depth, about 11 km. The strongest earthquake known to us in Turkey, at least as far as we measure earthquakes, occurred in 1939. In Greece, the strongest earthquake in the last 100 years occurred at Amorgos with a magnitude of 7 ,5.

If we calculate that the castle in Gaziantep was built by Justinian and fell and rebuilt at least four times, then we can make an initial estimate that such strong earthquakes occur every 400 years. The particular fault that ruptured yesterday does not appear to have caused major earthquakes for at least 120 years, which is the period in which we quantify global earthquakes.

In 1999, a magnitude 7.6 earthquake in the Gulf of Nicomedia near Istanbul killed about 18,000 people and triggered a 2-meter tsunami. I am afraid that yesterday’s earthquakes will cause many more victims, and we may never know the exact number, because entire families will be forced to leave their homes. We already know that about 5,000 houses and apartment buildings have collapsed. Count at least about 5 victims on average, and the numbers become tragic. Obviously, thousands of other buildings are already uninhabitable.

Most of the videos on the internet showing the collapses are from this second quake, the strongest of which occurred at night. Both quakes “promise” a post-seismic sequence, proportionately, with quakes greater than 6.3 degrees. This could lead to tens of thousands more casualties.

Crisis management is extremely difficult, earthquakes directly affected about ten million people, tens of thousands were left homeless and injured, and rescue operations will last days, and then we will know ten thousand. 13 thousand rescuers, 315 cars and about 600 cranes have already rushed to them. Two major local hospitals have collapsed, but three new hospitals are in operation. The weather conditions are unfavorable and the 20,000 tents already sent are not enough, many more are needed. Political differences between Turkey and Syria leave no room for optimism about mutual assistance, and for now it seems that rescuers have not yet arrived in isolated areas.

In the video from Gaziantep, we see neighboring buildings with completely different earthquake behavior. Assume that ground acceleration did not reach the devastating 2011 Christchurch, New Zealand earthquake. There is a lot of debate in Greece about the quality of construction in the neighboring country, either about obviously poor construction or substandard materials. . Turkey has particularly modern building codes, which, like Greece, were modernized after the 1999 earthquakes. An example is the three newest hospitals built in the last decade and in operation. The application of the rules, and especially the updates provided, often depends on the professionalism of the engineers and the common sense of the owners or buyers. What would happen to our country during a 7.5 magnitude earthquake at a small depth of focus under a residential area, or what would happen if an earthquake with a magnitude of about 8.5 magnitude occurred somewhere in the Greek arc, as it happens about once a 600-800 years old, with the last one being made in 1303 AD?

The differential response of neighboring buildings to an earthquake reminds us of tipping points in human and natural systems such as buildings and climate. When such a system goes beyond its critical point, overloading it, the consequences become relatively unpredictable, like the earthquake we just experienced. Common sense in the application of the rules would help to have fewer victims. Thus, common sense, as well as the scientific community at large, indicate that we must strive as a global community and as human beings not to exceed the goals of climate neutrality and a maximum increase of 1.5 degrees above zero in our daily choices. by 2050, otherwise we will end up in a global crisis thousands of times more serious and difficult to manage than the one that, unfortunately, is unfolding in Gaziantep.

* Costas Synolakis is an academic, professor of natural disasters and president of the National Science Committee on Climate Change.