Marmara Sea seismic activity: Dozens of micro-earthquakes recorded near Istanbul

Marmara Sea seismic activity Princes' Islands fault micro-earthquakes Istanbul earthquake risk

A significant cluster of seismic activity has been recorded in the Marmara Sea near the Princes' Islands, with dozens of micro-earthquakes occurring between August 19 and 20, 2026. Data from AFAD and Kandilli Rasathanesi indicate that the tremors, ranging in magnitude from 1.1 to 3.2, were concentrated at depths between 7 and 17 kilometers.

Geologists and seismologists have provided varying assessments regarding the implications of this activity. Prof. Dr. Şener Üşümezsoy stated that the tremors are occurring on secondary and tertiary fault segments rather than the main fault line, and noted that the Adalar fault is an old structure unlikely to produce a major earthquake. Similarly, Prof. Dr. Okan Tüysüz emphasized that while the activity confirms the fault is active, it cannot be definitively interpreted as a precursor to a large-scale earthquake.

Other experts offered different perspectives. Prof. Dr. Osman Bektaş suggested the activity might indicate a slow creeping motion in the deeper sections of the fault. Meanwhile, Prof. Dr. Ahmet Ercan cautioned against public panic, noting that earthquake predictions cannot be made solely on the number of small tremors, and provided long-term projections for a major Marmara rupture between 2045 and 2075.

Entities

AFAD · Adalar Fault · Balıkesir · Istanbul · Kandilli Observatory · Kandilli Rasathanesi · Marmara Denizi · Marmara Sea · Osman Bektaş · Princes' Islands · Turkey

Claims

What the coverage asserts, and how many sources carry each claim.

[● 6 SOURCES] The micro-earthquakes only indicate that the fault is active and cannot be used as a definitive sign of an impending large earthquake. www.gazetepencere.com · www.haber16.com · www.konhaber.com · www.aydinlik.com.tr · www.ortadogugazetesi.com · +1 more
[● 6 SOURCES] The Adalar fault is an old structure and is not expected to produce a large-scale, destructive earthquake. www.sozcu.com.tr · isthaberler.com · www.ortadogugazetesi.com · www.tgrthaber.com · www.yenicaggazetesi.com · +1 more
[● 2 SOURCES] The micro-earthquake activity at depths of 10-13 km may indicate a slow creeping motion in the deeper parts of the fault. boldmedya.com · halktv.com.tr
[DISPUTED] The largest earthquake recorded during the seismic activity was a 3.2 magnitude tremor. www.sozcu.com.tr · bizimtv.com.tr · boldmedya.com · www.gazetebirlik.com · www.gazetepencere.com · +12 more
[● 2 SOURCES] The most likely period for a major rupture in Northern Marmara is 2075, with the earliest possible being 2045. www.ortadogugazetesi.com · www.haber7.com
[● 5 SOURCES] Recent seismic activity is occurring on secondary and tertiary fault segments rather than the main fault line. www.sozcu.com.tr · isthaberler.com · www.ortadogugazetesi.com · www.tgrthaber.com · www.haber7.com
[● 17 SOURCES] Between August 19 and 20, 2026, dozens of micro-earthquakes occurred in the Princes' Islands area of the Marmara Sea. www.sozcu.com.tr · bizimtv.com.tr · boldmedya.com · www.gazetebirlik.com · www.gazetepencere.com · +12 more
[● 3 SOURCES] The seismic activity in the Princes' Islands area occurred at depths ranging from approximately 7 to 17 kilometers. www.gazetebirlik.com · www.mersinhaber.com · www.konhaber.com