Research on Ocean Floor Electrical Surveys.
Abstract
An important problem faced by the U.S. Navy is that of detecting submarines at greater ranges with airborne magnetic sensors that can now be done. One of the limits to the range at which detection is possible is the confusion of submarine-generated signals with natural-field pulsations of the earth's magnetic fields. One approach to the removal of the natural magnetic noise is that of monitoring the fluctuations at a moving airborne system. This requires two assumptions: the magnetic field of variations are coherent over the range on which cancellation is accomplished, and the correlation between magnetic field effects at the two sites is not dependent on the geology at either the mobile station or the reference site. Experience with geophysical surveys indicates that coherency of the magnetic field does exist; but, also, in water depths up to several thousand feet, the magnetic field is dependent upon geology at the observation site. This leads to a requirement for a method to evaluate the effect of subsea geology on local micropulsation behavior. In the research described in this report, three general categories of subsea electrical surveys were reviewed: direct current resistivity surveys, magnetotelluric soundings, and seafloor based electromagnetic system.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1984
- Accession Number
- ADA149831
Entities
People
- A. A. Kaufman
- G. V. Keller
Organizations
- Colorado School of Mines