Türkiye evaluates disaster readiness on Marmara earthquake anniversary

On the anniversary of the Marmara earthquake, experts emphasized the importance of raising disaster awareness in society and drew attention to the individual and collective measures that need to be taken for disaster preparedness.

It has been 26 years since the Marmara earthquake, which struck on Aug. 17, 1999, with its epicenter in the Gölcük district of Kocaeli, northwestern Türkiye. One of the most devastating earthquakes in Türkiye’s history, official records indicate that more than 17,000 people lost their lives, tens of thousands were injured, and hundreds of thousands were left homeless.

The 7.4 magnitude earthquake, which occurred at 3:02 a.m., lasted 45 seconds and caused widespread destruction primarily in Kocaeli, Sakarya, Yalova and Istanbul, leaving deep scars and massive losses in collective memory.

On the anniversary of the earthquake, experts evaluated the measures taken so far and emphasized the importance of raising disaster awareness in society.

Professor Nurcan Meral Özel, director of Boğaziçi University’s (BÜ) Kandilli Observatory and Earthquake Research Institute (KRDAE), stated that earthquake awareness in Türkiye has increased significantly since 1999 and that structural reinforcement works, building inspections, earthquake zoning plans and disaster awareness initiatives have become widespread.

Drawing attention to comprehensive reinforcement works on public buildings and transportation structures, Özel said, “The Urban Transformation Law was implemented. The law on building inspections, passed in 2001, authorized building inspection institutions and construction processes began to be carried out under a combination of private inspections and public oversight. Important regulations, such as the requirement for site managers and technical personnel, were introduced.”

Özel also highlighted the educational initiatives, noting that universities have launched Emergency Aid and Disaster Management programs. “In primary and secondary education curricula, ‘Disaster Awareness’ and ‘Earthquake Education’ courses or in-class activities have been added.”

She added: “Drills have become mandatory. Events such as Earthquake Week activities, drills and awareness days have been organized. Books and educational materials have been updated. Topics like appropriate behavior during an earthquake, safe zones and preparing disaster kits have been included in the curriculum.”

Regarding risk transfer, Özel recalled the establishment of DASK in 2000 and stated, “All reports prepared by 2011 were compiled by the Disaster and Emergency Management Presidency (AFAD) and approved by the Council of Ministers as the National Earthquake Strategy and Action Plan.”

She also said: “However, it is known that most of Türkiye’s building stock was constructed before 2000, that buildings are insufficiently earthquake-safe and that the inspection system is ineffective. Leaving or transforming unsafe buildings is not economically feasible in the short term. Societal preparedness has not yet been fully achieved.”

Özel emphasized that the fault segments in the Marmara Sea have significant earthquake potential. “Calculations show that the elastic energy accumulated in these segments is sufficient for an earthquake of magnitude 7 to 7.5. At KRDAE, our seabed seismometer network within the Marmara Sea allows us to monitor seismic activity with high resolution and in real-time.”

She added that these records provide important information about the deformation characteristics of the Marmara Fault through microearthquake activity, which terrestrial stations cannot detect.

“Current data show that the main fault line consists of both locked and creeping segments. The Adalar segment is largely locked at shallow depths. Partial creep is observed in the eastern part of the Central Marmara Basin. Approximately 120 kilometers (74.5 miles) of seismic gap remain unbroken after the 1912 Ganos (Mw 7.4) and 1999 Izmit (Mw 7.4) earthquakes, with a significant slip deficit in this region.”

Özel also mentioned that the 6.2 magnitude earthquake on April 23, 2025, off Silivri occurred in the western part of the Kumburgaz segment of the Marmara Fault, affecting a fault section approximately 15-20 kilometers long.

“According to our preliminary reports, the ruptured area measures about 15 kilometers by 9.5 kilometers, with a displacement of around 30 centimeters. This event only affected a limited portion of the segment; the remaining locked sections remain intact and continue to accumulate stress. This earthquake did not eliminate the regional earthquake hazard; on the contrary, it shows that risk persists and that a major rupture in the future remains possible,” Özel.

Özel explained that a 2025 study produced 87 three-dimensional dynamic earthquake rupture scenarios for the main Marmara fault. “These scenarios indicate that the rupture of the eastern Kumburgaz Basin and Adalar segments is likely. However, due to low locking rates and past ruptures, the expected earthquake magnitude may not exceed 7.4.”

She added that scientific studies suggest that the worst-case scenario with the widest impact in the Marmara region would involve simultaneous rupture of the eastern Kumburgaz (off Avcılar) and Adalar segments, producing an earthquake of approximately magnitude 7.3-7.4.

Özel noted that most buildings in Istanbul and the surrounding areas were built under outdated earthquake regulations, making them insufficiently resilient. Pre-1999 buildings are especially at risk, with reinforcement efforts progressing slowly. While newer buildings meet current standards, high population density and the prevalence of old structures mean overall preparedness remains inadequate.

She emphasized that individuals should prepare emergency plans and assess their building’s risk, while society should support reinforcement of risky buildings, participate in disaster drills and engage in awareness activities. Urban planning should prioritize evacuation routes, assembly areas, and robust infrastructure.

Geological engineer Okan Tüysüz said earthquakes became a major public concern after Aug. 17, 1999, when a densely populated economic hub was struck. He highlighted past earthquakes in 1939, 1942, 1943, 1957 and 1967, noting that communication limitations at the time reduced public awareness.

Recalling the 6.1-magnitude Sındırgı earthquake, he pointed out that despite only one casualty, over 600 buildings were heavily damaged, showing that building quality remains a concern. While search and rescue efforts have improved, minimizing damage and building societal resilience remain challenges.

Tüysüz urged practical individual measures, including family disaster education, preparing emergency plans, securing belongings, keeping beds away from glass and installing stoves safely. Combined with responsible governance, these steps can help Türkiye become more disaster-resilient.