November 11, 1922 Earthquake: Atacama, Chile

1922, November 10, 23:53 [local time]. 29 S 71 W, magnitude 8.25, intensity XI. There was a very strong earthquake in the southern part of Atacama province, with a zone of destruction approximately from Copiapo to Coquimbo. It was felt from Iquique to Concepcion (according to other sources, from Antofagasta to Valdivia) and from Buenos Aires to San Felix Island (where volcanic activity may have intensified). The underwater cables broke near shore at depths of 100 and 2200 m. The instrumental and macroseismic epicenters were fixed at sea in the region of Vallenar - Huasco. This tsunami generating earthquake began with relatively weak, but comparatively rapidly intensifying oscillations, lasting from 1/2 to 8 minutes according to different estimates. The chief of the seismic station of Copiapo described the earthquake as follows:

A terrible roar was heard, like loud peals of thunder, which awakened all those who were asleep. At the same time, ground oscillations began with an intensity of 4-5 degrees (V according to Rossi Forel), intensifying in 20 seconds to 7 degrees (VIII). The tremors then reached their maximal intensity and continued, without abating, for another 3 minutes, then gradually began to die down. According to other sources, the earthquake began with abrupt vertical shocks; essentially, it consisted of two independent tremors.

At Copiapo and other places, it was mainly flimsy structures (pise homes) on loose soils which suffered damage. More than 500 people died. Luminous discharges in the atmosphere were observed at many places. It is possible that a slight elevation of the coast took place in the Chanaral region.

The earthquake was preceded by strong foreshocks, felt on the 3rd and 7th of November. Seismic activity in the focal zone of the earthquake was high for two months.

(above from reference #415)

The magnitude of the main shock was 8.4, according to Richter. (reference #252)

1922, November 11. Magnitude 8.3 MS, 8.5 Mw. (reference #1314)

1922, November 11 04:32:45.21 UTC. 28.553 S, 70.755 W, depth 35 km, magnitude 8.7 Mw P&S. (reference #9910)

1922, November 11 04:32:51.44 UTC. 28.293 S, 69.852 W, depth 70km, magnitude 8.3 Mw. (reference #10476)

1922, November 11 04:32:51 UTC. 28.293 S, 69.852 W, depth 70km, magnitude 8.5 Mw. (reference #13456, #13546)

we suggest the rupture did not reach Coquimbo southward and did not reach Chañaral northward, and far from it since it did not even reach Caldera. (reference #14085)