This undersea earthquake generated recorded tsunami waves across coastal and trans-oceanic sectors. Preserved in seismic archive for scientific reference — no active hazard exists.
A magnitude 7.6 (MW) earthquake occurred on 1999-08-17, 03:01 local time (00:01 UTC) (9928d ago), centered Near İzmit (Turkey). The hypocenter was located at a shallow depth of 17 km. Primary telemetry verified by USGS/ISC-GEM alongside 1 regional seismic monitoring networks.
Curated Global Seismic Archive (1700–Present)
3.79 Mt TNT
shallow (Shallow crustal)
Injuries: > 5,000 · ~36.4M felt
Timeline of foreshocks, main rupture, aftershocks and machine learning risk probability evolution.
Shaking intensity is modelled from magnitude, depth and distance (GMPE attenuation), not reported by residents.
| Town | Distance | Intensity |
|---|---|---|
| İzmit · Kocaeli | 6.6 km | MMI X |
| Sakarya · Sakarya | 46 km | MMI VIII |
| Adapazarı · Sakarya | 47 km | MMI VIII |
| Bilecik · Bilecik | 68 km | MMI VIII |
| Istanbul · Istanbul | 82 km | MMI VIII |
| Bursa · Bursa | 91 km | MMI VIII |
Independent solutions for the same rupture. Differences of 0.1–0.3 in magnitude are normal and reflect method and station coverage.
| Agency | Source ID | Magnitude | Depth | Epicenter |
|---|---|---|---|---|
USGS Primary | official19990817000139_30 | M 7.6 | 17 km | 40.75, 29.86 |
Nearest mapped active fault: North Anatolian Fault (Marmara Branch), 5 km away, slip rate ~15.0 mm/yr (GEM Global Active Faults).
View live seismic monitoring, historical danger benchmarks, fault slip models and recurrence intervals for this zone.