Further deep resistivity measurements in the Pacific Northwest

This paper presents further results of a largescale crustal resistivity program in the Pacific Northwest. In an earlier paper [Cantwell et al., 1965] we discussed measurements made in northern Oregon and Washington. Since that time further measurements have been made in southern Oregon and northern California. The Bonneville Power Administration, in cooperation with the Department of Reclamation, the City of Los Angeles, and other agencies, is planning a EHV, dc power tie between the Pacific Northwest and the Southwest. As part of the preliminaries of this program, a study was begun in 1963 of the effects of large amounts of current injected into the earth, since the possibility existed that on occasion a ground return path would be required. We used these test ground return currents for deep resistivity measurements. Details of the experiment and data interpretation have been published in the previous paper and apply to the further measurements reported here.