Unveiling Earth's Hidden Magnetization

Abstract

AbstractRock magnetization carries information about rocks' properties, Earth's tectonic history, and evolution of its core magnetic field. One way to study Earth's magnetization is through the magnetic signal it generates, known as the lithospheric magnetic field. Although there exist global lithospheric magnetic field models of high spatial resolution, this path has not yet been very fruitful because of an important limitation: only part of the magnetization is visible, that is, produces an observable magnetic field signal. We refer to the remaining part of the magnetization as the hidden magnetization, and we recover it from a lithospheric magnetic field model under a few reasonable assumptions. We find that Earth's hidden magnetization at high and middle latitudes is very similar, both in intensity and shape, to Earth's visible magnetization. At low latitudes, the estimated hidden magnetization relies on a priori information and can be very different from the visible one.