October 26, 986 Tsunami: Marmara Sea, Turkey
A tsunami caused by a magnitude 7.5 earthquake began at Marmara Sea, Turkey on October 26, 986.
Where the waves reached
The source of the tsunami. No runup with a place is recorded for it.
- Under 1 m
- 1 to 3 m
- 3 to 10 m
- 10 to 30 m
- 30 m and more
- Height not recorded
Travel times
How long the first wave took to reach each part of the ocean, one line for each hour up to 24, estimated from the source and the depth of the sea.
The travel times are computed in your browser, which needs JavaScript.
- 1 to 4 hours
- 5 to 6 hours
- 7 to 14 hours
- 15 hours and more
Computed in your browser the way NOAA’s own travel time maps are: the wave travels at the square root of gravity times the depth, over NOAA’s ETOPO1 depths averaged to a 10 arc-minute grid. Checked against NOAA NCEI’s maps for 21 tsunamis over the first 24 hours, these lines fall within 10 minutes of NCEI’s at half the points compared and within 52 minutes at 9 in 10. They give when the first wave could arrive, not how high it is; bays, harbors and island chains finer than the grid can see it later. Not for use in a warning: see tsunami.gov.
The tsunami
- Date
- October 26, 986
- Source
- Marmara Sea, Turkey
- Cause
- Earthquake
- Earthquake
- Magnitude 7.5
- Runups recorded
- 0
- Tsunami intensity (Soloviev-Imamura)
- 4
- Waters
- Ocean
- How certain
- Probable tsunami
- Source location
- 40.800° N, 29.200° E
The toll
The record gives no deaths, injuries or damage for this tsunami.
More
Every tsunami in 986The 900sTsunamis of TurkeyThis day in weather historyAlerts in force
Sources
Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 3430.