A Probabilistic Assessment of the Next Geomagnetic Reversal
Article
English
OPEN
Buffett, B
;
Davis, W
(2018)
 Publisher: eScholarship, University of California

arxiv: Physics::Geophysics
©2018. American Geophysical Union. All Rights Reserved. Deterministic forecasts for the next geomagnetic reversal are not feasible due to large uncertainties in the presentday state of the Earth's core. A more practical approach relies on probabilistic assessments using paleomagnetic observations to characterize the amplitude of fluctuations in the geomagnetic dipole. We use paleomagnetic observations for the past 2 Myr to construct a stochastic model for the axial dipole field and apply wellestablished methods to evaluate the probability of the next geomagnetic reversal as a function of time. For a presentday axial dipole moment of 7.6 × 1022 A m2, the probability of the dipole entering a reversed state is less than 2% after 20 kyr. This probability rises to 11% after 50 kyr. An imminent geomagnetic reversal is not supported by paleomagnetic observations. The current rate of decline in the dipole moment is unusual but within the natural variability predicted by the stochastic model.