Dependence of the duration of geomagnetic polarity reversals on site latitude

Bradford M. Clement ()
Additional contact information
Bradford M. Clement: Florida International University

Nature, 2004, vol. 428, issue 6983, 637-640

Abstract: Abstract An important constraint on the processes governing the geodynamo—the flow in the outer core responsible for generating Earth's magnetic field—is the duration of geomagnetic polarity reversals; that is, how long it takes for Earth's magnetic field to reverse1. It is generally accepted that Earth's magnetic field strength drops to low levels during polarity reversals, and the field direction progresses through a 180° change while the field is weak1. The time it takes for this process to happen, however, remains uncertain, with estimates ranging from a few thousand up to 28,000 years. Here I present an analysis of the available sediment records of the four most recent polarity reversals. These records yield an average estimate of about 7,000 years for the time it takes for the directional change to occur. The variation about this mean duration is not random, but instead varies with site latitude, with shorter durations observed at low-latitude sites, and longer durations observed at mid- to high-latitude sites. Such variation of duration with site latitude is predicted by simple geometrical reversal models, in which non-dipole fields are allowed to persist while the axial dipole decays through zero and then builds in the opposite direction, and provides a constraint on numerical dynamo models.

Date: 2004
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.nature.com/articles/nature02459 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:428:y:2004:i:6983:d:10.1038_nature02459

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/nature02459

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().