20.08.2026 07:40
Seismic activity that began off the coast of Istanbul's Princes' Islands continued throughout the night. Nearly 50 small tremors were recorded in the region, and the successive earthquakes have brought the question 'Is this a harbinger of the great Marmara earthquake?' back to the agenda. While Prof. Dr. Okan Tüysüz, Prof. Dr. Ahmet Ercan, and Prof. Dr. Şener Üşümezsoy evaluated the activity, Üşümezsoy said, 'The Princes' Islands fault is an old and dead fault. A large earthquake will not occur from here.'
The earthquakes that occurred off the coast of the Princes' Islands in Istanbul yesterday continued throughout the night. Fifty small tremors, the largest of which was 2.5, caused panic. After the tremors, the largest of which was 3.2, attention turned to geoscientists. Three expert names evaluated the relationship between this seismic activity and the expected major Marmara earthquake.
NEARLY 50 TREMORS THROUGHOUT THE NIGHT
The activity, which began just two days after the 27th anniversary of the August 17, 1999 earthquake, intensified especially after 16:08. After a 3.2 magnitude tremor recorded in an approximately two-hour period, the region shook like a cradle throughout the night. Experts noted that nearly 50 micro-earthquakes, the largest of which was 2.5, also occurred during the night hours.
EXPERTS' CALL: "DON'T PANIC"
Seismologists evaluating the seismic activity in the region agreed that successive tremors cannot be directly interpreted as a precursor to a major earthquake.
Prof. Dr. Okan Tüysüz: He emphasized that the events only show that the Princes' Islands fault is active. Tüysüz summarized the situation with these words: "Every major earthquake is followed by aftershocks, but not every major earthquake is preceded by foreshocks. Whether an earthquake is a foreshock is only understood after a major earthquake follows. We will wait and see."
Prof. Dr. Ahmet Ercan: Stating that earthquake prediction cannot be made by looking only at the number of small tremors, he warned the public against unnecessary panic. Ercan, who predicts a maximum tsunami (sweeping) wave of 2.5 meters for the expected major Marmara earthquake, pointed to 2045 as the earliest date and 2075 as the most likely period for the rupture timeline.
"THE PRINCES' ISLANDS FAULT IS DEAD, NO MAJOR EARTHQUAKE WILL OCCUR"
Geoscientist Prof. Dr. Şener Üşümezsoy, on the other hand, explained that the activity occurred not on the main fault line, but on secondary and tertiary fault branches cutting the region from south to north. Stating that these branches do not have the stress accumulation to produce a destructive earthquake, Üşümezsoy noted that the tremors are a normal energy release and made the following striking assessment:
"The Princes' Islands fault is an old and dead fault. No major earthquake will occur from here."