How did experts evaluate the earthquake?

The 7.7 magnitude earthquake, whose epicenter was Şehitkamil in Gaziantep, left dozens of people dead and hundreds trapped under the rubble. According to the data from Boğaziçi University Kandilli Observatory, after the first earthquake that occurred at 04:17 at a depth of 5 kilometers, aftershocks, the highest of which reached 6.6, occurred in Gaziantep, Diyarbakır, Kahramanmaraş, Elazığ, Malatya, Adıyaman, Kilis, Hatay, Osmaniye and Bingöl. Experts evaluated the earthquake for Bloomberg HT. Prof. Dr. Ziyadin Çakır, Head of ITU Geological Engineering Department, evaluated the earthquake that occurred in Kahramanmaraş and affected 10 provinces. Çakır, who was a guest on Bloomberg HT, said that he could not say anything definite since it was not known which fault line was broken, but that it was a 7.8 magnitude earthquake as given by international institutions. The highlights of his speech are as follows: "It should be accepted as a 7.8 magnitude earthquake" “The largest earthquake in Turkey since the 1939 Erzincan earthquake affected a very large area. It was a region that had been quiet for a long time. We think that the fault line from Hatay to Malatya has broken. All of the 6-5 magnitude earthquakes are aftershocks because the aftershocks of a major earthquake are also large. Frankly, we are not sure which fault line has broken at the moment. We think that about 200-250 pieces have broken from the distribution of these vehicles, but we are not very sure. The information provided by international institutions is more reliable and they give a 7.8, 7.4 is not very accurate. There are even those who give a 7.9. It should be accepted as a 7.8 magnitude earthquake. There are not many pieces left to break on the North Anatolian fault except in Istanbul.”