Millions of people spent a difficult night in Istanbul and the surrounding areas after the 6,2-magnitude earthquake that caused no casualties or serious damage, but reminded everyone that Turkey's largest city is located in a tectonically dangerous spot.
Aftershocks continued throughout the night of Wednesday into Thursday, almost all of them with magnitudes not exceeding 3 on the Richter scale, with a 4,2 Richter tremor in the early hours of Thursday.
Thousands spent the night in open spaces, lighting fires to keep warm. At the same time, authorities are asking citizens to stay away from buildings.
Moreover, memories are still fresh from the two earthquakes measuring 7,8 and 7.7 on the Richter scale that leveled southwestern Turkey and neighboring Syria in early 2023, leaving behind approximately 60.000 dead in both countries.
Turkish authorities say more than 230 people, mostly in Istanbul, were injured when they tried to jump from buildings during the earthquake. Almost all have been discharged, but none have life-threatening injuries.
For safety reasons, schools in the areas affected by the earthquake will be closed on Thursday and Friday.
The scripts
In its preliminary research, the Department of Geology and Geophysics of Istanbul University states that the earthquake is related to only part of the faults (the western one) in the Sea of Marmara region and recommends caution and vigilance.
Turkish experts also point out that Istanbul is located near faults that could cause even larger earthquakes with devastating results.
Professor Murat Utoksu, who spoke to Hurriyet, speaks of a tremor that is a harbinger of the major earthquake we are expecting in Istanbul, as potential has been accumulating for many years that will one day "break out." He also connects the seismic activity of recent years with the major earthquake of 1999, in the southern part of the Sea of Marmara.
He emphasizes, however, that we cannot know when this major earthquake will occur.
Turkish seismologist Dr. Naci Gorur predicted an earthquake of over 7 on the Richter scale in Istanbul.
In a post on social media, Gorour warned residents and authorities to take timely measures, as he stated that he does not believe that the 6,2 Richter earthquake was the main earthquake.
"This earthquake will more or less affect the part of the fault that is expected to rupture in Marmara," said the professor, who returned to platform X with a terrifying prediction of an earthquake greater than 7 on the Richter scale.
"There are many earthquakes in Istanbul on the Kumburgaz fault in the Sea of Marmara. They are of different magnitudes. They are not the big earthquakes we expect in Marmara. They increase the pressure that builds up in this fault. The real earthquake here will be bigger and above 7," he wrote in a post.
What do Greek seismologists say?
Greek seismologists appear particularly cautious.
Although the tremor comes from a known seismic fault, it is nevertheless of great concern that the epicenter is located in a section of 60-70 kilometers, which, as Geology professor and president of OASP, Efthymios Lekkas, pointed out to protothema.gr, “had not broken until now, however its potential is much greater and therefore there is a lot of energy accumulated there”. In fact, as he points out, the tremors that have followed so far do not allow complacency. Mr. Lekkas even says that we cannot say with certainty that the 6,2 Richter is the main earthquake.
"In the coming days and certainly in the coming period, we must be on the alert. Historically, we know that the area had an earthquake of close to 7,5 on the Richter scale in 1715, and then there was damage to Hagia Sophia," says Mr. Lekkas, pointing out that the fact that the tremors that have followed the 6,2 Richter so far are located at the same epicenter, there is no "dispersion", while he considers 2-3 earthquakes of the order of 6,2 to 6,5 on the Richter scale to be a possible development for the release of the accumulated energy, is also worrying.
When asked whether seismic activity in Turkey could trigger a fault in Greece, Mr. Lekkas replies that such a thing is possible, but of course it cannot be predicted which one.
With this data, seismologists are closely monitoring the evolution of the phenomenon and the coming days will show whether this is the main earthquake or whether this particular fault can produce an even more powerful tremor.
Speaking to protothema.gr, the director of the Geodynamic Institute, Mr. Vasilis Karastathis, speaks of a normal seismic sequence, noting, however, that it is too early to draw conclusions regarding the evolution of the phenomenon.
"So far, the phenomenon appears to be developing somewhat normally. It is, of course, very early and we must be cautious. However, it does not present any characteristics that cause concern so far. The potential of this particular zone is great, but that does not necessarily mean that it will exhaust it. I hope this is the earthquake that will give rise to it and de-escalate it," said Mr. Karastathis.
At the same time, he points out that this particular zone has produced large earthquakes in the past, but the fault that caused the 6,2 Richter magnitude has been inactive for more than a century.
"This particular zone is very large and has repeatedly produced major earthquakes. This particular part, of course, was the one that had not 'broken'. It had many decades to produce a major earthquake. It has been producing since 1900," he emphasizes.
For his part, seismologist, Mr. Gerasimos Papadopoulos, speaks of an area with high seismic potential into which the North Anatolian fault enters and branches.
"So far there is an aftershock sequence but we cannot be sure if this was the main earthquake. We need more data in the coming hours and days to get a picture. This is an area with high seismic potential, with many large, active faults that have in the past caused earthquakes of up to 7 on the Richter scale. In this specific case, in the Sea of Marmara, the North Anatolian Fault enters and branches. In 1999, another branch of the North Anatolian Fault was activated," Mr. Papadopoulos tells protothema.gr.
The earthquake
The 13-second earthquake struck Turkey at 12:49 (local and Greek time) on Wednesday, April 23.
The shallow surface depth - just 10 kilometers for the main earthquake - and the relatively short distance from Istanbul - 40 kilometers south and southeast - made the tremor particularly felt in a large part of western Turkey, but also on Aegean islands and northern Greece and Bulgaria.
Dozens of aftershocks were recorded in the first few minutes, with the strongest one measuring 4,9 on the Richter scale.
Source: protothema.gr
