January 6, 1856 Tsunami: Azores, Portugal
A tsunami of unknown cause began at Azores, Portugal on January 6, 1856. The water rose as high as 10 meters.
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
The tsunami
- Date
- January 6, 1856
- Source
- Azores, Portugal
- Cause
- Unknown
- Maximum water height
- 10 m (32.8 ft)
- Runups recorded
- 0
- Waters
- Ocean
- How certain
- Very doubtful tsunami
The toll
- Damage
- Limited (under about $1 million)
- Houses destroyed
- Few (about 1 to 50)
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.
1856 January 6. Azores. Large tsunami at Velos, Ilha de Sao Jorge. Damage done to the walls of the town and to several houses. (reference #41)
1856 January 6. Seismic and submarine slide source tsunami. Avellar (1902) reports the occurrence of a ''terrible coastal flood" at Velas (S. Jorge) on 6 January 1856, which wrecked the schooner Leonor by "three great tides between ten and eleven AM". Although this account is somewhat vague and one might suspect a storm-generated event, a tsunami origin is given in the NGDC database. Such an origin is corroborated by the extension of damage caused to stone structures (including defence walls and houses) and by the reported runup of the flood (more than 10 m in the "cerca de Sao Francisco"), exceeding by far the most extreme storm surge recorded at this location. In addition, according to this account, the inhabitants were allowed time between successive on-rushes to rescue stranded boats (placing them in a street where the present day elevation is of some 16-17 m above mean sea level), thus implying that the period of the sea-surface oscillation was unusually large. (reference #5046)
1856 January 6, Very doubtful tsunami, Meteorological cause. Considering the available descriptions on S. Jorge and S. Miguel islands it is more likely that the floods and damage observed are related to a meteorological phenomenon (storm), as interpreted by Guedes and Oliveira (1997). (reference #13057)
More
Every tsunami in 1856The 1800sTsunamis of PortugalThis 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 855.