Gravity results in western Washington



Gravity surveys in western Washington have been conducted by this author and University of Puget Sound students since 1962, and about 5000 gravity measurements have been made. Two instruments have been used: Worden meter 358, owned by the University, and a LaCoste-Romberg G-68 loaned by the Army Map Service, which has also financed the survey during the past four years.

Simple Bouguer corrections are applied to all stations; terrain corrections have been calculated for selected points and soon will be derived for all stations by a computer program written by R. Krimmel. Most stations are located where elevations have been determined by other agencies (USGS, USCGS, Corps of Engineers, railroad and power companies, highway construction crews, etc.), and some level lines have been run by our own group. In other cases, barometric elevations were used, but their reliability is poor. The survey datum is based on Woollard's [1958] network, and is tied into previous or contemporary work by Bonini (p. 531), Stuart [1961, 1965], Jones, [1952], Christensen et al. (p. 548) and Walcott [1967].