evidence: - Magnetic field reversals may cause the ionosphere to contact the surface of the Earth during the reversal period. [...] - ↑ 6.0 6.1 Richard B. Stothers (31 July 1986). "Periodicity of the Earth's magnetic reversals". Nature 322 (6078): 444-6. doi:10.1038/322444a0. http://www.nature.com/nature/journal/v322/n6078/abs/322444a0.html. Retrieved 2015-06-17. [...] - ↑ 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 Norbert R. Nowaczyk and Helge Arz (16 October 2012). Ice age polarity reversal was global event: Extremely brief reversal of geomagnetic field, climate variability, and super volcano. ScienceDaily: Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences. https://www.sciencedaily.com/releases/2012/10/121016084936.htm. Retrieved 2016-11-04.