Will the earthquake in Yalova trigger a potential Marmara earthquake? An expert explains...

The 4.1 magnitude earthquake that occurred off the coast of Çınarcık in Yalova recently caused anxiety among citizens living in Istanbul and its surrounding areas. Mining Technology and Earth Sciences Expert Serkan İçelli stated in his explanation that the earthquakes occurring in the Gemlik Gulf would not affect other faults located within the Sea of Marmara.

"WE ARE EXPECTING AN EARTHQUAKE UP TO 6.4 HERE"

İçelli stated that an earthquake of 6.5 magnitude could occur between Gemlik and Mekece, saying, "People are rightfully worried. We are particularly concerned about the Marmara Region. First of all, we recently had an earthquake in the Gemlik Gulf. This is a fault that ruptured in 985 and 1863 AD. It was a fault that came from the Iznik-Mekece line, exited through Gemlik, and entered further into the Marmara. We had a 5.1 magnitude earthquake here. People are asking many questions about whether this 5-magnitude earthquake is a foreshock. We are expecting an earthquake of up to 6.4 here. Because when we calculate the annual slip rate for the earthquake that occurred here in 985, it reached 6.5 to 7.0. If this earthquake happened in the past, the probability of a 6.4 magnitude earthquake occurring in the same way in the future is very high. But the fault in the Gemlik Gulf cannot have triggered the other faults within the Marmara. Because they all run parallel to each other."

"EARTHQUAKES OF 6.5 MAGNITUDE CAN OCCUR ON THE 35-KILOMETER UNBROKEN FAULT IN MARMARA"

Stating that a 6.5 magnitude earthquake could occur on the 35-kilometer unbroken fault in Marmara, İçelli said, "As you know, we had an earthquake in Gölcük in 1999. Following this earthquake, pressure built up on the Armutlu block, which we call the southern branch. As a result of this stress transfer, we will expect earthquakes here from now on, especially in the Gemlik Gulf section. Of course, the fault in Gölcük ruptured in 1999. Therefore, we will not expect a major earthquake in the Kocaeli-Yalova section. Our unbroken fault is on a 35-kilometer segment in Istanbul. The 4-magnitude earthquake in Yalova-Çınarcık does not trigger the 35-kilometer fault in Istanbul. It is beneficial for Yalova and Çınarcık to be particularly careful. We may experience earthquakes that could reach 6.0 and 6.4 here. There is a slip underground in the Marmara Region. When we look at the focal mechanisms of the earthquakes 10 kilometers below and above, this creep is clearly visible. The earthquake here is dissipating. It does not produce a major earthquake, but rather earthquakes averaging around 5.5 to 6.0. It does not produce a 7-magnitude earthquake. Earthquakes of 6.5 magnitude can occur on the 35-kilometer unbroken fault in Marmara."

"FOUNDATIONS MUST BE BUILT ACCORDING TO THE SOIL, AND STRUCTURES ACCORDING TO THE FOUNDATION"

Touching upon the precautions that can be taken for earthquakes, İçelli emphasized that foundations should be built according to the soil and structures according to the foundation, stating, "Some news has been circulating in recent days. That the probability of an earthquake in the Marmara Region has risen to 47 percent. Calculations in a study conducted in 2016 revealed that the probability of an earthquake in the Marmara Region would be 47 percent. But in other studies, it is seen as 29 percent. When you say 47 percent, you think as if there is a 47 percent risk of an earthquake at any moment, but there is no such situation in Marmara. Let's think of it this way: we should consider this as a 2 percent annual probability of a 7-magnitude earthquake. But there is no 7-magnitude earthquake energy here. For our citizens around Marmara, first of all, we will be prepared for an earthquake. We will first conduct drills in our homes. We need to determine our escape routes. But most importantly, foundations must be built according to the soil, and structures according to the foundation. A 6.5 magnitude earthquake would cause destruction in Istanbul."

News Source: İHA