Rapid geomagnetic changes inferred from Earth observations and numerical simulations.

ABSTRACT: Extreme variations in the direction of Earth's magnetic field contain important information regarding the operation of the geodynamo. Paleomagnetic studies have reported rapid directional changes reaching 1° yr^-1, although the observations are controversial and their relation to physical processes in Earth's core unknown. Here we show excellent agreement between amplitudes and latitude ranges of extreme directional changes in a suite of geodynamo simulations and a recent observational field model spanning the past 100 kyrs. Remarkably, maximum rates of directional change reach  ~10° yr^-1, typically during times of decreasing field strength, almost 100 times faster than current changes. Detailed analysis of the simulations and a simple analogue model indicate that extr

SUBMITTER: Davies CJ 

PROVIDER: S-EPMC7338531 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature