September 20, 1935 Tsunami: Bismarck Sea, Papua New Guinea
A tsunami caused by a magnitude 7.8 earthquake began at Bismarck Sea, Papua New Guinea on September 20, 1935 at 01:46:43 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
The tsunami
- Date
- September 20, 1935, 01:46:43 UTC
- Source
- Bismarck Sea, Papua New Guinea
- Cause
- Earthquake
- Earthquake
- Magnitude 7.8, 30 km deep
- Runups recorded
- 1
- Waters
- Ocean
- How certain
- Probable tsunami
- Source location
- 3.824° S, 141.416° 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.
1935, September 20. N. coast of Aitape, New Guinea. "The sea! - Look at the sea!" I heard some natives should and I saw that the ocean seemed to be receding from the beach. After the first series of shocks the tremors diminished until they were barely discernible, but the sea was now pulled back until the whole of the foreshore was dry; then as I watched the tide started to return. It came in great breakers although the outer sea remained calm. The great waves swept up over the coast towards me and in places flooded inland. Where the land was low the sea went many hundreds of yards in shore. (reference #99)
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 |
|---|---|---|---|---|---|---|---|
| Aitape | Papua New Guinea | 128 | Eyewitness observation of water height |
More
Every tsunami in 1935The 1900sTsunamis of Papua New GuineaThe 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 1683.