Abstract
A VIOLENT Pacific Ocean earthquake, late on August 21 near the coast of British Columbia, was the occasion for a very successful operation of the Hawaiian seismic sea-wave warning service developed by the U.S. Coast and Geodetic Survey. Upon the arrival of the earthquake waves, automatic alarms connected with seismographs sounded at the Survey's observatories at Honolulu, Hawaii ; Tucson, Arizona ; and Fairbanks, Alaska. The observers at all of these stations immediately attended their instruments, developed records and made readings. Tucson and Fairbanks promptly communicated theirs to the central station at Honolulu. Based upon these reports, the observer at Honolulu determined an almost exactly correct epicentre location and issued preliminary advisory warnings to military and public authorities at Honolulu in about one hour and a half after the time of the earthquake. This warning preceded the estimated arrival time of a seismic sea-wave, which might have resulted from this earthquake, by about four hours. Subsequent inquiries and messages to tide stations in Alaska showed that a small seismic sea-wave was produced ; however, no such wave reached Hawaii in damaging proportions. The earthquake, though little publicized, was actually of greater magnitude than the disastrous recent earthquake of Ecuador, South America.
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Pacific Ocean Earthquake of August 21. Nature 164, 560 (1949). https://doi.org/10.1038/164560b0
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DOI: https://doi.org/10.1038/164560b0