December 1, 1928 Earthquake: Talca, Chillan, Santiago, San Fernando, Chile

On 1928, December 1, 1928, at 0:07 [local time] there was an earthquake which destroyed Talca and Constitucion. At Talca, strong vertical shocks lasted 1 minute 45 seconds; a fire broke out after the earthquake; the city was almost totally destroyed; 108 people died; railway, telegraph and telephone links with the city were broken. At Constitucion, the breakwater sank to one side. Sixty-seven people died; about another 50 people died at other settlements in the epicenter zone. Shortly after the earthquake, the rock dump at the Baraona copper mine in the upper part of the Cachapoal valley collapsed; 54 miners died. At Putu settlement, which was almost totally destroyed by the earthquake, the shore was lifted up and the water line receded more than 200 m.

A strong seaquake was felt on the "Santa Elisa" and "Poseidon" steamships situated 11-13 km off shore at Constitucion, in the direction of Valparaiso. The crew of the "Santa Elisa" reported that the vessel experienced "a strong trembling; it first appeared that some force was raising it above the water, and then tossing it down to the

depths." Waves of unusual size moved in every direction on the surface of the sea; a clear moonlit night made it possible to observe the waves for a considerable distance. This phenomenon lasted no more than 112 minutes. The steamship "Magdala" also felt a seaquake at 35o 33.5' S., 72o 54' W.

The zone of damage by the earthquake stretched from Valparaiso to Concepcion. The intensity of tremors varied greatly even at adjacent points, depending on soils and other peculiarities of geological structure. The earthquake was felt at Antofagasta, Buenos Aires and Puerto Montt.

After the earthquake, high seismic activity was observed in the focal zone. It gradually abated in the first months of 1929.

During the entire morning of December 1, irregular flood and ebb tides of unusual height were observed off the coast of Central Chile: At Constitucion, the water rose an estimated 1.5 m above the diurnal high tide line.

(above from reference #415)

Reference #552 lists magnitude 8.4.

Reference #1314 lists magnitude 7.6 Mw.

Reference #252 lists 252 deaths, severe damage.

Reference #1206 lists intensity IX.