August 21, 1859 Tsunami: Imroz - Aegean Sea, Turkey
A tsunami caused by a magnitude 6.9 earthquake began at Imroz - Aegean Sea, Turkey on August 21, 1859 at 11:55 UTC. Its effects were recorded at 1 place.
Where the waves reached
The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.
- 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
- August 21, 1859, 11:55 UTC
- Source
- Imroz - Aegean Sea, Turkey
- Cause
- Earthquake
- Earthquake
- Magnitude 6.9
- Runups recorded
- 1
- Tsunami intensity (Soloviev-Imamura)
- 3
- Waters
- Ocean
- How certain
- Very doubtful tsunami
- Source location
- 40.200° N, 25.800° E
The toll
- Damage
- Moderate (about $1 to $5 million) with the earthquake or eruption that caused it
- Houses destroyed
- Many (101 to 1,000) with the earthquake or eruption that caused it
Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.
What the record says
NCEI’s account, from the sources it cites.
"It was thought the earthquake was felt between 30 and 43 degrees North for a distance of 8 degrees along the longitude. The ground in low places cracked and water streamed out of the fissures." (reference #2130)
Some sailors at sea reported the disappearance of Gokceada for a moment. The sea waves observed at the northern approaches of the Strait of Istanbul could not be related with this event (reference #9275)
Every runup
Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.
| Where | Country | Km from source | Water height, m | Inland, m | Measured by | First wave, UTC | Deaths |
|---|---|---|---|---|---|---|---|
| Imroz - Aegean Sea | Turkey | 6 | Eyewitness observation of water height |
More
Every tsunami in 1859The 1800sTsunamis of TurkeyThe earthquakeThis 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 3381.