Magnetic Methods, Airborne

Synonyms

Aeromagnetics

Introduction

Making measurements from the air of the Earth’s magnetic field is a well-established geophysical survey method. The normal practice is to measure the scalar amplitude of the magnetic field in the survey area, this being referred to as the total magnetic intensity (TMI), the name reflecting the fact that the measurements represent the resultant of all the magnetic fields, of whatever source, in the vicinity of the measurement. The major contributions come from the geomagnetic field and the fields due to magnetic rocks in the upper crust, the latter being the fields of interest.

Initially used to infer the depth to magnetic rocks beneath nonmagnetic cover in sedimentary basin studies and for identification of major lineaments, the products from aeromagnetic surveys have evolved to now be a reliable means of creating detailed maps of the near-surface geology. Current developments in aeromagnetics are mostly related to the increasingly sophisticated...