August 17, 1906 Earthquake: South Central, Chile

There was an extremely strong earthquake in the center of Chile, with source near Valparaiso. According to the director of the meteorological observatory at Santiago, the earthquake began suddenly without any preliminary rumble and with marked oscillations. Their amplitude gradually increased; strong oscillations lasted 1 1/2 minutes. According to other sources, the earthquake lasted 4-5 minutes in the focal zone.

The earthquake was felt as far as Tacna (Peru), Buenos Aires, Chiloe Island and the Juan Fernandez Islands. The seaquake was felt at Deseado Cape (Atlantic coast of Argentina). According to the Central International Seismological Bureau at Strasbourg and a number of investigators who collected press reports the intensity of temors at individual points was [IX-X Rossi Forel at Casablanca, Limache and Quillota].

The axis of the pleistoseismic zone of the earthquake may have been directed along the 20o azimuth. Weak structures on loose soil were almost the only ones destroyed. The territorial distribution of damage in such large cities as Valparaiso and Santiago is especially significant in this respect. At Valparaiso, damage was mainly done not by the earthquake itself, but by the subsequent fire. Limache was almost completely destroyed; 116 of 3000 residents died. The northern part of San Antonio was buried under a large mud flow. Many water and mud gryphons were formed on the plain near Curepto.

The residents of many coastal settlements observed luminous phenomena at the time of the earthquake (lightning, diffuse luminescence, falling stars, phosphorescent air near the ground, sparking of wires, etc.).

The shore at some places in the focal area was elevated 0.7-0.8 m and then slowly returned to its previous position. Apparently, due to the latter fact, the authenticity of the elevation was questioned by many specialists, including Montessus de Ballore, who soon after headed the seismological service in Chile.

A high level of seismic activity in the focal area continued for 18 months.

[The earthquake generated a tsunami that was observed all around the Pacific.]

(above from reference #415)

1906, 8:40 p.m., magnitude 8.6, Valparaiso, 4000 deaths. (reference #1170)

August 17, 1906, Valparaiso, 3,800 deaths, $260 million damage. (reference #1051)

1500 deaths, $100 million damage. (reference #1250)

Epicenter August 17, 1906, 0040 UTC, 33S, 72W, magnitude 8.4. (reference #415)

Magnitude 8.2 Mw. (reference #1314)

1906, August 17 00:40:00 UTC. 33 S, 72 W, 8.2 M GSX, 8.5 Mw P&S. (reference #9910)