Repeat-station surveys: implications from chaos and ergodicity of the recent geomagnetic field

• Main Authors: Angelo De Santis, Enkelejda Qamili, Gianfranco Cianchini
• Format: Article
• Language: English
• Published: Istituto Nazionale di Geofisica e Vulcanologia (INGV) 2013-04-01
• Series: Annals of Geophysics
• Subjects: Magnetic repeat stations; Chaos; Ergodicity
• Online Access: http://www.annalsofgeophysics.eu/index.php/annals/article/view/5491

<p>The present geomagnetic field is chaotic and ergodic: chaotic because it can no longer be predicted beyond around 6 years; and ergodic in the sense that time averages correspond to phase-space averages. These properties have already been deduced from complex analyses of observatory time series in a reconstructed phase space and from global predicted and definitive models of differences in the time domain. These results imply that there is a strong necessity to make repeat-station magnetic surveys more frequently than every 5 years. This, in turn, will also improve the geomagnetic field secular variation models. This report provides practical examples and case studies.</p><p> </p>