Magnetic Survey

magnetic survey

[mag′ned·ik ′sər‚vā]
(geophysics)
Magnetometer map of variations in the earth's total magnetic field; used in petroleum exploration to determine basement-rock depths and geologic anomalies.
Measurement of a component of the geomagnetic field at different locations.

Magnetic Survey

 

systematic measurements of the components of geomagnetism and compilation of magnetic charts based on measurement data.

A distinction is made between general and detailed magnetic surveys. A general magnetic survey, which is carried out over large areas with a comparatively sparse network of measurement sites (separated by tens or hundreds of kilometers), provides for the study of the basic principles governing the distribution of the geomagnetic field. Charts compiled on the basis of a general magnetic survey are essential for maritime and air navigation, for finding significant magnetic anomalies, and for studying the secular change of the components of geomagnetism. A detailed magnetic survey with a distance of 1 m to several kilometers between measurement sites (strips) is used mainly for geological mapping and prospecting for ore deposits.

In a magnetic survey the absolute value of the vector of the total intensity of the geomagnetic field is usually measured, but for purposes of geological surveys efforts are often limited to relative determination of the vertical component of the field. A magnetic survey is carried out by various types of magnetometers carried by satellites, aircraft, nonmagnetic ships, and surface vehicles. Continuous observations of variations in the geomagnetic field over time (the secular change of the field) are made by networks of magnetic observatories.

REFERENCE

lanovskii, B. M. Zemnoi magnetizm [3rd ed.], vol. 1. Leningrad, 1964.
References in periodicals archive ?
Outside of the Hillside project a detailed magnetic survey over the entire Pine Point Copper Belt (60km in length) has revealed multiple large scale copper targets.
Company president Peter Bliss says a high-resolution airborne magnetic survey conducted in September revealed about 10 "high priority" targets among about 30.
The initial targets were selected from high level, widely spaced government aeromagnetic maps by Southern Era Resources from whom the properties are optioned; a subsequent low level, closely spaced, high resolution magnetic survey has identified 15 priority targets in the 6,000 acre area which contains the indicator minerals.
is pleased to report that the company has completed the ground based magnetic survey over the target area of the Marcella concession.
Melbourne, Australia, Oct 12, 2009 - (ABN Newswire) - A detailed regional magnetic survey covering 60 kilometres of the Pine Point Copper Belt on the Yorke Peninsula in South Australia has opened up a host of new exploration targets on Rex Minerals Limited's (ASX:RXM) 100% owned tenements.
Large Scale Regional targets - Successful targeting using a detailed magnetic survey at Hillside (over an area of 10km2) could open up a new frontier of multiple large scale copper-gold targets along the Pine Point Copper Belt (area of 1000km2).
Based on the ground magnetic survey, the pipe is circular with a diameter of approximately 1,000 feet.
TSX VENTURE:PXC) announced today that it has received final results from the airborne magnetic survey conducted by McPhar Geosurveys Ltd.
BHP Billiton) has started a large Falcon(TM) airborne gravity gradiometer and magnetic survey over the company's 100% owned 7,648 km2 West Falcon Gobi Property in southern Mongolia.
An airborne electromagnetic and magnetic survey comprising 870 survey line-kilometers will commence shortly on the Key Project.
The Midas, high-resolution, helicopter-borne magnetic survey employs two boom-mounted, high sensitivity magnetic sensors flown over the property at very low altitudes (35 to 40 metres above gound).
In February 2005, Patrician Diamonds acquired the Sahtu Property based on subtle but anomalous magnetic features that had been delineated by a Geological Survey of Canada regional airborne magnetic survey.