sondage magnétique différentiel

CONT: Nous l'avons appelée «sondage magnétique différentiel» en raison du principe sur lequel elle est fondée.

CONT: Differential Geomagnetic Sounding. The use of arrays of magnetometers in the last few years made it possible to study lateral anomalies of conductivity of the earth. Most of these studies were concerned with anomalies of horizontal extension between 100 and 1000 km. Parkinson (...) and Wiese (...) characterized the geomagnetic anomalies by defining the ""Parkinson vector."" They allow the anomalies to be mapped by using different events recorded at different stations.
OBS: In the French texts consulted, ""magnétique"" was used to convey the same meaning as ""geomagnetic"" when referring to ""sondage.""