The U. S. Geological Survey's program of Alaskan gravity observations

The U. S. Geological Survey began gravity surveys in Alaska in 1958. About 700 observations were made along the highways and on the shores of major lakes in the area covered by the Copper River aeromagnetic survey. During the following years the gravity measurements were extended to include parts of the Alaska Range and Tanana Valley, and they have gradually evolved into a program designed to prepare a reconnaissance gravity map of the whole state within the next five years. Before the surveys began, published data from gravity surveys in Alaska consisted of records from (1) about 6000 stations obtained in a 26,000‐square‐mile area of northern Alaska, Naval Petroleum Reserve 4, by the U. S. Navy and by United Geophysical Corporation [Woolson, 1962]; (2) about 500 widely scattered stations observed by members of the University of Wisconsin [Thiel et al., 1958; Woollard et al., 1960]; (3) a few traverses near Prince William Sound by the Carnegie Institution of Washington [Tatel, 1956]; and (4) some control stations established by the U. S. Coast and Geodetic Survey [Rice, 1958]. Petroleum companies had already made surveys (unpublished) of the Bethel basin, Nushagak basin, Cook Inlet basin, Yakataga geosyncline, and some other possible petroleum areas.