The Mw 6.2 Western Marmara Sea earthquake on 23 April 2025 ruptured the Kumburgaz segment of the Main Marmara Fault at shallow depth, causing one fatality, 359 injuries, and slight damage to 4,295 buildings, while major infrastructure and lifeline systems remained operational. Given its relatively limited consequences, it was classified as a moderate earthquake. However, this report argues that the event's real significance lies in what it revealed about Istanbul’s readiness for a larger future earthquake.
The report covers the following:
- Characterisation of the event
- The built environment: seismic code evolution, risk assessments and hidden vulnerabilities
- Seismic risk mitigation in practice: assessment, retrofit and urban transformation
- Preliminary urban damage prediction from recorded ground motions
- Observed impact: built environment
- Observed impact: societal response
- Observed impact: economic repercussions
- Disaster assembly areas and urban preparedness
- Conclusions and forward look