Last Updated on 4 August 2025 by Johan
The 17 August 1999 İ̇zmit earthquake struck northwestern Turkey at 03:01 local time (00:01 UTC), registering a moment magnitude of 7.6 Mw and reaching a maximum Mercalli intensity of X. The shock originated about 15 km beneath the surface along the North Anatolian Fault and lasted approximately 37 seconds.
This catastrophe claimed between 17,127 and 18,373 lives, injured some 43,953–48,901 people and left about 5,840 missing. It generated a local tsunami up to 2.52 m high and inflicted US $12–20 billion in damage. Entire neighborhoods in Kocaeli and Sakarya provinces were levelled; key facilities like the Turkish Navy headquarters in Gölcük and the Tüpraş oil refinery in İzmit collapsed. In Istanbul, hundreds perished and thousands of structures were damaged.
The quake was part of a westward-migrating seismic sequence on the North Anatolian Fault, which since 1939 has produced major shocks across northern Turkey. The August 17 event involved a roughly 120 km rupture of four fault segments, with right-lateral displacements of 3–4 m along the fault trace.
In its aftermath, Turkey introduced an “earthquake tax” to fund reconstruction and founded the National Disaster Insurance Institution to mandate seismic coverage. Public outrage over substandard construction and lax enforcement of building codes led to criminal probes of contractors and accelerated adoption of earthquake-resistant design standards.
Rescue and relief efforts were spearheaded by the Turkish Red Crescent and the armed forces, with Greece’s rapid aid delivery fostering a rare thaw in bilateral tensions. Lessons from 1999 continue to drive improvements in early warning systems, emergency response protocols and cross-border disaster cooperation along one of Europe’s most active fault zones.