Immediate precautions needed for quake prep: Experts

ISTANBUL

Experts have warned for an immediate need to take precautions against an expected big Marmara earthquake in the aftermath of the 5.7-magnitude earthquake that shook Istanbul on Sept. 26.

A group of academics from Istanbul Technical University (İTÜ) said in a written statement that the 5.8-magnitude earthquake and its predecessor – a 4.6-magnitude earthquake, which struck the Marmara Sea on Sept. 24, occurred on a fault line where the experts believe the expected big Marmara earthquake is going to occur.

“The geological, geodesic and seismologic analyses done at the [Marmara] sea floor shows that the Kumburgaz fault line has not been broken for a long time and is locked, and it is the fault line segment where the expected Marmara Sea earthquake will take place. The 4.6- and 5.7-magnitude earthquakes happening on the end point of the totally locked Kumburgaz fault line segment points to how critical the situation is,” said the statement issued on Sept. 26.

“Based on seismologic analyses, it has been concluded that the two earthquakes in question and all of the aftershocks that happened in between occurred within the scope of the same mechanical fracture process. Based on scientific indicators, the current seismic activity needs to be followed and necessary precautions need to be taken,” said the statement.

The Sept. 26-dated earthquake was assessed at a magnitude of 5.7 both by the Kandilli Observatory and Earthquake Research Institute and the U.S. Geological Survey. The earthquake was at a depth of 12.6 kilometers, the observatory said, locating its epicenter 70 kilometers west of Istanbul in the Marmara Sea, south of the district of Silivri. It struck at 1.59 pm. Turkey’s Disaster and Emergency Management Authority (AFAD) said the quake had a magnitude of 5.8.

A group of experts from the Kandilli Observatory held a press meeting in the aftermath of the quake, saying the Marmara region has not gone through such “earthquake activity” in the last 20 years and called on people to be vigilant.

“Since 1999, there is common consensus among scientists that the North Anatolian fault in the Sea of Marmara is accumulating strain. Therefore, we are expecting a big earthquake in the Sea of Marmara,” Aslı Doğru, the institute’s deputy director, said.

“But for now, we cannot say for sure whether this quake is its precursor. But of course, everyone should be on red alert; our citizens should be cautious,” she added.

Doğan Kalfat, a senior researcher at the institute, said that the 5.7-magnitude earthquake had shown how prepared the Marmara provinces were in the face of a bigger expected quake. “There are damaged buildings structure-wise, even if partially…There have been problems in the communication and traffic,” he said, referring to the cellular telephone networks being down for about two hours after the quake struck.

“Therefore, this was a test for us for the expected big earthquake,” he added.

Experts for years have been warning against a big earthquake in the Marmara region. The expected quake is forecasted to have a magnitude of a maximum 7.6.

Turkey’s worst seismic disaster in recent history is the Aug. 17, 1999 Marmara earthquake that had a magnitude of 7.4. The epicenter of the quake was near İzmit city, 104 kilometers east of Istanbul. More than 17,000 people were killed, over 285,000 buildings were damaged and 600,000 people were left homeless after the 45-second quake, which left social and economic wounds that took years to heal.