September 29, 1880 Earthquake: Alaska Peninsula, United States

Reference #239:

1880, September 29, 04:00 GMT. From U.S. Signal Corps Annual Report for 1182 (U.S. War Department, 1883, p. 120): September 28, 1880, 6 P.M., three very heavy and successive shocks, direction of the first shock N to S, the remaining two from W to E; 9 P.M., severe shock from W to E. 29th 3 A.M., very heavy shock from W to E; 1 P.M. Extremely heavy shock from W to E. From the commencement of this phenomenon, September 28, 1880, until its subsidence October 16, 1880, there was an uninterrupted trembling motion of the earth interspersed with heavy subterranean rumbling sounds. During a short trip over a portion of the island [Ukamok or Ookanon, now known as Chirikof] on September 29, deep fissures with a width of from 15 to 20 inches were found to be numerous. The residence of Mr. Newlander, one story high and substantially built of logs, was situated about 500 yards from shore [the Southwest Anchorage], on rising ground and about 20 feet above sea level. During the heavy shocks shelves were wrenched from the walls, a brick stove upset, the flooring twisted out of shape and heavy beef and flour barrels (full) were pitched from one side of the room to the other. Outside of the building no one was able to stand on their feet owing to a violent jerky, and rotary motion of the earth, which continued for at least 20 minutes. The action upon bodies of water is given as follows: Several times at low water the sea rose in a body, traveling inshore about 60 yards, when it would subside, immediately followed by a succession of similar waves. The water in the creeks overflowed their banks to the eastward, as indicated by the condition of the ground on that side, which was dotted by numerous small pools of water, some of which were fully 40 yards distant from the east bank. On the south side of the island a small, shallow creek, across which one could easily stepped previous to the earthquake, was now widened about six feet; the fresh water was changed to salt water, and the depth was so increased that the bottom was not discernible. After the shocks, heavy breakers were observed on the southwestern shore of the island, where, for the past four years, no such phenomenon has been observed. On the west side of the island, the tide does not rise as high as before the shocks.

Moore (1962, p. 9) reports that the northeast trending boundary fault was tilted abruptly to the southeast and the southeast boundary fault showed showed vertical displacement of 6 feet still preserved in damned streams and uplifted wave cut terraces. Petroff (1884, p. 90-91) mentions that the earthquake was felt in the Semidi Islands and Chrikof Island. It was not felt at Kodiak and the adjoining islands. The marigrams from Kodiak, Honolulu, and Sausalito were examined for this study and no unusual activity was noted. The shock must have been very local to have produced such a sharp earthquake with a vertical uplift of 6 feet and a tsunami. It was not felt at Kodiak nor recorded on the Kodiak tide gage. The shore would have had a very gentle slope if the house was 150 feet from the shore and still only 20 feet above sea level.

Soloviev and Go (1974) following Petroff suggest a connection between this event and the October 26, 1880 (Julian date) event at Sitka. These are two separate events. This event clearly was local to Chirikof with observed faulting and the October 26 tsunami appears local to Sitka. Validity 3.

Reference #414:

1880. A strong earthquake occurred with the formation or renewal of a surface fracture on Chirikof Island. [There was a tsunami at Sitka in the same year.]