magnetometer

Device for measuring the intensity and orientation of the magnetic field of a particular rock or of a certain area. In geology, magnetometers are used to determine the original orientation of a rock formation (or the orientation when the magnetic signature was locked in), which allows for past plate reconstruction. They are also used to delineate ‘magnetic striping’ on the sea floor in order to make plate reconstruction and to prospect for ore bodies such as iron ore, which can disrupt the local magnetic field.

A magnetometer was used to confirm the phenomenon of seafloor spreading by detecting symmetrical stripes of alternating polarity on either side of the mid-Atlantic ridge.