Turkish seismologists are confused about the continuity of seismic behavior in the Istanbul and Marmara Sea region after the strong 6.2-magnitude earthquake on Wednesday, April 23.

Several seismologists, most notably the widely known Naji Giorur, have expressed the view that this earthquake is a “precursor” to the large 7.2 magnitude earthquake expected in the same area and will release ten times more energy – perhaps even more on a logarithmic scale if the earthquake is stronger – than the last strong tremor.

Note that seismologists divide the northern branch of the northern Anatolian section of the fault that runs through the Sea of Marmara into three parts. The eastern part is the one that gave the great 7.4-magnitude earthquake in the Gulf of Nicomedia in 1999, the western part that reaches up to the Gulf of Xeros in Eastern Thrace and exits into the North Aegean Sea had given a similar magnitude earthquake in 1912, while the central part is the one that was in a trance and gave the earthquake of April 23.

They also sound the alarm that the continuity of the fault to the east and up to the fault that gave the 1999 earthquake has not yet “broken” and that the April 23 earthquake is creating trends that when they reach a critical point will give a new earthquake.

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According to seismologists who are still expecting the big earthquake of more than 7 degrees, the eastern continuation of the fault that gave the last earthquake and passes through the sea country south of the center of Istanbul has not “broken” yet, it is still accumulating energy and the April 23 earthquake is exerting tensions and therefore the big earthquake is closer in time to this point.

Professor of seismology, Naji Giorur, says “this is not the big earthquake we are expecting. The tension concentrated on the fault is decaying. The real earthquake will be bigger and will exceed 7 Richter.” In a post he wrote: “the Istanbul earthquake (Marmara earthquake) will happen. The latest earthquakes of April 23 brought the Istanbul earthquake even closer.”

Istanbul Technical University (ITU) geophysics professor Okan Touisuz says there is still an expectation of a major earthquake in the Sea of Marmara. “Since August 17, In the already sliding ground of this region since August 17 (the big earthquake of 1999), there has been a 15% transfer of stresses and brought the expected earthquake closer.”

Most seismologists also agree on the fact that there is a gradual evolution taking place over time and that yesterday’s 6.2 magnitude is a continuation of the 5.8 magnitude that the fault gave in 2019.

On the other hand, other seismologists appear more optimistic and argue that the 6.2 Richter is a strong earthquake that is currently releasing the accumulated energy in a fault that has not given a major earthquake in over 250 years.

Professor Sener Usumezzoi is a special case, as he had predicted the 1999 earthquake and a few weeks ago said he expected an earthquake in the 6-6.5 magnitude range in the area where the 6.2 tremor finally occurred off Silesia. “Yesterday, the Marmara earthquakes ended. Be at peace,” he said the day after the big quake. He stressed that “the expected earthquake in Marmara is over and there will be no more big earthquake,” and reacted harshly against his colleagues who claim that a big Istanbul earthquake is “on the way.” “From now on, earthquakes are ‘silenced’. I know the Sea of Marmara like the palm of my hand,” he insisted.

And Professor Osman Bektas says “there is no cause for concern. There may be aftershocks but we don’t expect a bigger earthquake. Because the fault here, up to this much energy could accumulate.”

Prestigious geophysics professor Ovgyun Ahmed Ercan expresses a view that could be described as following a middle path. He said that “as much energy was released as the Hiroshima bomb. I said that before the main 7.2 magnitude earthquake there would be 6 magnitude earthquakes. This is one of them”. He does, however, place the very strong earthquake more than 20 years from now. “This was not the big Istanbul earthquake we were expecting. We still have time for it. I don’t think it will happen before 2045 and 2065,” he said.