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Interim report on the St. Elias, Alaska earthquake of 28 February 1979

Open-File Report 79-670
By: , , , , and 
https://doi.org/10.3133/ofr79670

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Abstract

On 28 February 1979 an earthquake with surface wave magnitude (Ms) of 7.7 (W. Person, personal communication, 1979) occurred beneath the Chugach and St. Elias mountains of southern Alaska (fig. 1). This is a region of complex tectonics resulting from northwestward convergence between the Pacific and North American plates. To the east, the northwest-trending Fairweather fault accommodates the movement with dextral slip of about 5.5 cm/yr (Plafker, Hudson, and others, 1978); to the west, the Pacific plate underthrusts Alaska at the Aleutian trench, which trends southwestward (Plafker 1969). The USGS has operated a telemetered seismic network in southern Alaska since 1971 and it was greatly expanded along the eastern Gulf of Alaska in September 1974. The current configuration of stations is shown in Figure 9. Technical details of the network are available in published earthquake catalogs (Lahr, Page, and others, 1974; Fogleman, Stephens, and others, 1978). Preliminary analysis of the data from this network covering the time period September 1, 1978 through March 10, 1979, as well as worldwide data for the main shock will be discussed in this paper.

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Interim report on the St. Elias, Alaska earthquake of 28 February 1979
Series title Open-File Report
Series number 79-670
DOI 10.3133/ofr79670
Year Published 1979
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Earthquake Science Center
Description 23 p.
Country United States
State Alaska
Other Geospatial St. Elias Mountains, Chugach Mountains
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details