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Updated: Jul 31, 2026
11:04
Geomagnetic Field (Gmf) and Plant Evolution: Investigating the Effects of Gmf Reversal on Arabidopsis thaliana Development and Gene Expression
Published on: November 30, 2015
Earth's magnetic field is probably not reversing
Maxwell Brown1,2, Monika Korte2, Richard Holme3,4
1Institute of Earth Sciences, University of Iceland, 101 Reykjavík, Iceland; maxwell@hi.is.
Summary
The Earth's geomagnetic field is weakening, but historical models suggest it will recover naturally. Past geomagnetic field behavior, including excursions, does not mirror current changes, indicating no imminent reversal or excursion.
Area of Science:
- Geophysics
- Paleomagnetism
- Earth Science
Background:
- The geomagnetic field has been decaying significantly since at least 1840, prompting concerns about potential reversals or excursions.
- Indirect observations suggest this decay may have begun even earlier, possibly around 1600.
Purpose of the Study:
- To model the geomagnetic field behavior over the past 30-50,000 years.
- To analyze the dynamics of the Laschamp (41 ka) and Mono Lake (34 ka) geomagnetic excursions.
- To compare past field behaviors with current geomagnetic field changes.
Main Methods:
- Development of a geomagnetic field model spanning 30-50,000 years before present.
- Analysis of field intensity and structure during past geomagnetic excursions and anomalies.
- Comparison of modeled past field evolution with current geomagnetic field decay patterns.
Main Results:
- Neither the Laschamp nor Mono Lake excursions showed field evolution patterns similar to the current geomagnetic field decay.
- Geomagnetic field structures resembling today's South Atlantic Anomaly (SAA) were identified at 49 and 46 ka.
- These SAA-like fields did not evolve into excursions or reversals in the model.
- The 46 ka SAA-like field coincided with increased production of cosmogenic nuclides (beryllium, chlorine), despite no significant dipole field weakening.
Conclusions:
- The current weakening of the geomagnetic field is unlikely to result in an excursion or reversal.
- Past geomagnetic field behavior suggests a natural recovery process.
- The relationship between cosmogenic nuclide production and geomagnetic field changes is more complex than previously assumed.
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