May 25, 1751 Tsunami: Central Chile

1751, May (erroneously March) 24 or 25 (after 01:00, local time) there was a destructive earthquake and tsunami in Concepcion. The shock that occurred on the 26th was almost as strong as that of the 25th.The ocean began to recede about half an hour after the quake, and soon the half dressed, frozen and frightened inhabitants of Concepcion climbed the neighbouring hills from where they witnessed the approach of a strong sea wave descending upon the shore. The tsunami flooded the town (then situated in the site of Penco), and washed away the wreckage of buildings and domestic utensils. Seven minutes later the ocean returned with great force "the waves crowded one on another," and the water level exceeded its usual limits; the water burst into the town with a speed exceeding that of a galloping horse, completely inundating the town. The water advanced quickly along the river, rising and inundating the adjacent areas and flooding even houses on higher ground. Boats and canoes were hurled into the church of San Francisco, located 400-500 m from shore. Subsequently, the water receded, again quite rapidly, carrying with it walls, some of which were still intact, and household items. Where the town had stood there was nothing but an impassable heap of ruins. And in the Cantarranos quarter, only the piles of the houses were left, all the rest having been washed away. Then the water receded again, just as on the previous occasion, but it rose and inundated the area two more times, the third flooding being the most severe.

The next morning it was established that the water level had varied considerably; in some areas the water had risen more than 3.5 m (4 varas), in others less. Twenty-five to thirty old persons and invalids (17 persons, according to other accounts) were drowned in the waves of the tsunami - the only victims of the earthquake.

The vessel "St. Anthony and Family," loaded with goods and passengers, lay at anchor in the port of Concepcion. The seaquake was very severe and it was feared the vessel might be destroyed, but it survived. With the first strong ebb, the anchor chain broke, and the ship itself was grounded, listing heavily. The returning tide hit the vessel, causing it to list the other way. Then the vessel found itself floating. Subsequently, the sea rose 17 m (9 1/2 fathoms) and the ship was thus refloated. There were three strong tides and ebbs, and each time the vessel became grounded.

After this destructive flood - the fourth and most severe in the history of the city - Concepcion was rebuilt farther from the shore, and its old location was eventually used to build the new town of Penco. The tsunami was also recorded in Valparaiso.

The waves hit the island of Juan Fernandez, washed away a settlement and sank a vessel anchored in the port. The governor of the island, his family along with 35 other persons perished.

The tsunami reached threatening proportions in Callao; but no one died

There are some reports to the effect that the bottom of Concepcion Bay had risen 7 m (24 feet) during the earthquake; the resulting shoal consisted of hard sandstone rather than sand.

Naturalists who later visited the area of Concepcion, found, in areas of considerable elevation, many mollusc shells which were packed with river sand; such shells normally occur in the littoral zone.

The tsunami reached the southeastern coast of the island of Honshu, flooding the houses on Otsuki on the Djika peninsula and in Kesennuma to above the floors, but there were no deaths.

(above from reference #415)