MAGNETO-TELLURIC DEEP EARTH RESISTIVITY AT EIGHT U. S. TYPE-LOCATIONS.

Abstract

Magneto-Telluric measurements were carried out in eight 'type-areas' of the U. S., to see whether systematic differences exist in their deep crustal and upper mantle electrical resistivities. Digital recording, electrode spacings of tens of kilometers, and a frequency range of five decades were used at most locations. Results varied between those of the Adirondacks, where a resistive crust overlies a moderately conductive, strongly anisotropic mantle, to the thin resistive crust north of Spokane overlying a very thick, resistive intermediate layer. Where they can be compared with subsurface geological and electrical data our results agree with those data. In general, the Moho does not appear to be associated with a pronounced conductivity transition. Although an upper mantle conductivity increase is usual it is typically deeper than the Moho. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1969
Accession Number
AD0690608

Entities

People

  • A. S. Orange
  • H. S. Lahman
  • K. Vozoff

Tags

DTIC Thesaurus Topics

  • Conductivity
  • Electrical Conductivity
  • Electrical Properties
  • Electrodes
  • Frequency
  • Measurement
  • Physical Properties
  • Transitions

Readers

  • Geotechnical Engineering.
  • Plasma Physics.
  • Seismology

Technology Areas

  • Space
  • Space - Orbital Debris