August 17, 1952 Tsunami: Desecheo Island, US Territories

Reference#13840:

On August 17, 1952, I was marooned for twelve hours on the small, uninhabited island of Desecheo, some fifteen miles off the north-west coast of Puerto Rico. Suddenly, at about 4.30 p.m. local time, the sea withdrew along the western coast, sea-level being lowered perhaps 10 ft. There was a dull, muffled sound, followed by a remarkably rapid churning of the seas towards the west-north-west. Three hours later, seas were still very high, and it was next morning before I could be brought from the island. It was very warm, sunny and balmy all day. Later, it was discovered that rough seas had occurred along both coasts of Mona Passage.

For this date the San Juan Observatory recorded practically minimum microseismic activity, and nothing unusual was recorded in Martinique.

A study of synoptic weather maps of the NorthSouth Atlantic and Caribbean Sea for the above dates rules out the possibility of the rough seas being attributed to meteorological conditions. If storms of rapid development, perhaps even too rapid to have been recorded on synoptic charts, were the cause, then it is strange that the wild seas were such localized occurrences. A detailed check has shown that on and about the above dates no other West Indian island nor even the neighbouring mainlands recorded unusual seas.

There is no indication of submarine volcanic activity being the cause.

It would appear that it was neither earthquakes, meteorological storms nor submarine volcanoes which were responsible for these peculiarly localized phenomena along the coasts of the islands mentioned. The effect was purely local and a local cause must be sought.

[…] From the point of view of slope stability, the steep slopes north of Desecheo must naturally be viewed with suspicion.

Reference #12345 lists as questionable tsunami with a landslide source. (accessed July 2024)