Researchers report a high-resolution geomagnetic field record, spanning approximately 1,500 years, from two stalagmites in Brazilian caves located near the present-day minimum of the South Atlantic Anomaly, the weakest part of Earth's magnetic field; the record indicates recurrent periods of rapid directional change in the magnetic field consistent with westward migration, expansion, and intensification of reversed flux patches at the core-mantle boundary.
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Article #18-09197: "Speleothem record of geomagnetic South Atlantic Anomaly recurrence," by Ricardo I.F. Trindade et al.
MEDIA CONTACT: Ricardo I.F. Trindade, University of São Paulo, BRAZIL; tel: +5511984629595; e-mail: ricardo.trindade@iag.usp.br
Proceedings of the National Academy of Sciences