August 9, 1929 Tsunami: Northern Chile

On August 9, 1929, at Antofagasta at night, large waves were observed in the harbor, although there was nothing unusual about them. In places the waves poured over the parapet of the breakwater, situated at a level 7 m 50 cm above the highest high tide mark. By 22:00 an unusual drop in sea level was recorded. It rapidly reached a mark 1 m 30 cm below the lowest low tide mark, which could be clearly fixed from the dried up joints between the individual blocks of the embankment, already erected in section G of the port. This caused great alarm among the population, since a rapid and unusual rise of water was to be expected whose consequences would be hard to predict. In fact, several minutes later, three waves fell on the breakwater at 4 minute intervals and poured over the parapet along its entire length at once, forming a stream from 3 m 50 cm to 4 m deep. These waves made the first breach BC in the structure. Less than 2 hours later, about midnight, a rapid fall in level was again recorded, accompanied by another rise in level and the formation of unusual waves, which made the second breach DE near the outer end of the breakwater. Somewhat later, more waves of the same kind beached the remaining sections AB and CD. Until 11:00 of the following morning, one could see unusual waves, flooding the upright piece of the breakwater DE, which held, since it was considerably thicker than all the rest of the structure. [There are no instrumental or macroseismic data indicating an earthquake. Apparently, this was a storm tsunami.] (reference #415)