Tsunamis in 1772

April 5, 1772 Tsunami: Portugal

April 5, 1772 · Very doubtful tsunami

A tsunami caused by an earthquake began at Portugal on April 5, 1772.

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

Tsunami warnings in force

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
April 5, 1772
Source
Portugal
Cause
Earthquake
Earthquake
The earthquake
Runups recorded
0
Waters
Ocean
How certain
Very doubtful tsunami
Source location
38.000° N, 9.000° W

The toll

Damage
Limited (under about $1 million) 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.

1772 Apr. Portugal. off San Vicente, “near Cape St. Vincent in Portugal, [the captain] observed extremely rough seas lasting six minutes” found in the newspaper St. Petersburg Vedomosti. Listed as “probably a tsunami (most likely caused by a seaquake)” (reference #14362)

Note: Ref #496 lists earthquakes in Lisbon on April 05 and 10

More

Every tsunami in 1772The 1700sTsunamis of PortugalThe 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 505.