After the 7.7 and 7.6 magnitude earthquakes in Kahramanmaras, Turkey continues to shake with aftershocks and earthquakes while it has not yet healed its wounds. US earthquake expert Assoc. Dr. Judith Hubbard shared the seismic map of the 1999 earthquake on her social media account and warned about Istanbul.
The earthquake with magnitudes of 7.7 and 7.6, which took place 9 hours apart in Kahramanmaraş, destroyed 11 provinces. After the earthquakes, experts began to renew their warnings for Istanbul. US earthquake expert Assoc. Dr. Judith Hubbard shared the seismic activity in and around the Marmara Sea after the 1999 earthquake on Twitter and said, “The fault to the west of the fault that created the 7.6 magnitude earthquake in Istanbul in 1999 is the biggest concern.”
“EVERY YEAR 25 MM MOVE TOWEST”
Stating that the movements of the faults in and around the Marmara Sea are well known by experts, Assoc. Dr. Judith Hubbard said, “The Sea of Marmara and the surrounding area was one of the most seismically active regions in the world. There are many faults and recorded earthquakes. All due to the movement of tectonic plates. “The area in the south is moving westward by 25 mm every year” .
Describing the earthquake in Izmit in 1999, Hubbard, “For Istanbul, the fault just west of the fault that created the 7.6 earthquake in 1999 is the biggest source of concern. This North Anatolian Fault is one of the most active faults on the map. The 1999 Izmit earthquake was the last in a series of twelve earthquakes that began in the east in 1939. Where the North Anatolian Fault crosses the eastern Sea of Marmara, its influence is evident in the shape of the seafloor: a steep slope that borders the northern edge of a deep valley. This fault has been seismically quiet lately. This is not reliable. “Seismic gaps” are stress accumulating faults. This represents the stress that must be released in the end,” she said.
TOLD ON THE MAP OF THE 1999 EARTHQUAKE
Explaining that there was a seismic gap on the 1999 Izmit earthquake map, Hubbard, “This image shows seismicity colored by time. Seismicity orange in the east of Istanbul: these are the aftershocks of the 1999 earthquake. In the west, a darker red indicates newer seismicities. In the time series below, there is no signal of increasing seismicity in the south of Istanbul. Is it good? No. Look at the silence before the 1999 earthquake, the time before the main shock and aftershocks. This is how earthquakes often behave,” she said.
Explaining that there is a 47% chance of a 7.3 or greater earthquake near Istanbul for 30 years, Hubbard said, “Will there be an earthquake near Istanbul tomorrow? We don’t know. It might be, but it might be decades from now. This study points to an earthquake of 7.3 and greater at a rate of 47% near Istanbul over 30 years. This means that the probability of a major earthquake near Istanbul is 7.3 and about 2% every year”.
