HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Leading modes of torsional oscillations within the Earth's core

Abstract : The fluid core motion cannot be observed directly, however, it can be deduced from magnetic observations. This motion can be approximated as a set of coaxial cylinders rotating along the Earth rotation axis. Our study shows that the actual motion in the core corresponds to a set of oscillations propagating from the core-mantle boundary to the inner core (with diminishing amplitude) at period of 85, 50, 35 and 28 years, respectively. These oscillations appear to be very robust in our study, moreover two weaker modes have also been isolated and require further study. Zatman and Bloxham (1997) isolated two modes with periods that correspond to our first two modes. Comparing the theoretically predicted modes of Mound and Buffett (2007), all three analyses (one theoretically based and two based on geomagnetic observations) agree on the periods of the isolated modes; this concurrence is exceptional and provides strong evidence of the existence of the modes.
Document type :
Journal articles
Complete list of metadata

Contributor : Nathalie Pothier Connect in order to contact the contributor
Submitted on : Friday, March 11, 2022 - 4:10:09 PM
Last modification on : Saturday, March 12, 2022 - 3:32:32 AM


Geophysical Research Letters -...
Publisher files allowed on an open archive





Jean O. Dickey, Olivier de Viron. Leading modes of torsional oscillations within the Earth's core. Geophysical Research Letters, American Geophysical Union, 2009, 36, ⟨10.1029/2009GL038386⟩. ⟨insu-03604896⟩



Record views


Files downloads