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Bouguer gravity map of Alaska

Open-File Report 76-70
Prepared in cooperation with the State of Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys
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Abstract

The Bouguer gravity map of Alaska has been compiled from about 30,000 Alaska land gravity measurements plus approximately 40,000 km of surface-ship gravimeter traverses over the bordering continental shelves. The compilation thus represents nearly three times as much land data and ten times as much marine data as were available for one previous Alaskan gravity map (Barnes, 1969b) and fiftyfold increase since the original compilation of Alaskan land gravity data (Wollard and others, 1960). However, data from many parts of the state are still too scattered (inset 1) for accurate contouring; such deficiencies are most serious in the southwestern part of the state and in the Bering Sea.

The map shows the variation of the simple Bouguer anomaly field and is thus comparable to the existing Bouguer gravity map of the conterminous 48 states (Wollard and Joesting, 1964). On land the Bouguer anomaly contours reflect the regional variations of gravity better than free-air anomaly contours, which are not adequately corrected for topography. However, in oceanic areas the free-air anomaly is less sensitive to bottom topography than the Bouguer anomaly. Accordingly, the map coverage includes available data from the continental shelves where the bottom relief is small, but it has not been extended to cover the continental slope, the deep ocean, or the islands of the Aleutian arc, where the free-air anomaly would be a better indicator of the regional variation of gravity, and where Bouguer gravity are only available for a few small areas (Miller and Bath, 1969; Healy and Kibler, 1976a and 1976b).



Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Bouguer gravity map of Alaska
Series title Open-File Report
Series number 76-70
DOI 10.3133/ofr7670
Year Published 1976
Language English
Publisher U.S. Geological Survey
Description 1 Plate: 47.59 x 35.66 inches
Country United States
State Alaska
Projection Modified Transverse Mercator Projection
Scale 2500000
Google Analytic Metrics Metrics page
Additional publication details