October 20, 1981 Tsunami: Krakatau, Indonesia
A tsunami caused by a volcano and a landslide began at Krakatau, Indonesia on October 20, 1981. The water rose as high as 2 meters. 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
The tsunami
- Date
- October 20, 1981
- Source
- Krakatau, Indonesia
- Cause
- Volcano and landslide
- Volcano
- The eruption that caused it
- Maximum water height
- 2 m (6.6 ft)
- Runups recorded
- 1
- Waters
- Ocean
- How certain
- Probable tsunami
- Source location
- 6.102° S, 105.423° E
The toll
The record gives no deaths, injuries or damage for this tsunami.
What the record says
NCEI’s account, from the sources it cites.
However, one must consider the position of Anak Krakatau, in disequilibrium on the edge of the 1883 caldera (according to Sudradjat, 1981, or Camus and Vincent, 1983b); such instability may account far a small tsunami (approx. 2 m high), experienced in 1981, on Rakata island during the night (Oct. 19-20) of the awakening of Anak. The explosions were subaerial and the volume of products emitted by each explosion was small, and we did not observe other tsunamis during the day when the severity of eruptions increased. We suppose,therefore, that the tsunami could be related to a small landslide of the flank of Anak. (reference #12821)
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 |
|---|---|---|---|---|---|---|---|
| Rakata Island (Krakatoa) | Indonesia | 6 | 2 | Eyewitness observation of water height |
More
Every tsunami in 1981The 1900sTsunamis of IndonesiaThe eruptionThis 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 5759.