Recurrent ancient geomagnetic field anomalies shed light on future evolution of the South Atlantic Anomaly.

ABSTRACT: The strength of the geomagnetic field has decreased rapidly over the past two centuries, coinciding with an increasing field asymmetry due to the growth of the South Atlantic Anomaly. The underlying processes causing the decrease are debated, which has led to speculation that the field is about to reverse. Here, we present a geomagnetic field model based on indirect observations over the past 9,000 y and identify potential ancient analogs. The model is constructed using a probabilistic approach that addresses problems with age uncertainties and smoothing of sedimentary data that have hampered previous attempts. We find evidence for recurrent hemispherical field asymmetries, related to quasiperiodic millennial-scale variations in the dipole moment. Our reconstruction indicates that minima i

SUBMITTER: Nilsson A 

PROVIDER: S-EPMC9214526 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature