Oceanos magnéticos e Terra elétrica

quinta-feira, outubro 06, 2016

Satellite tidal magnetic signals constrain oceanic lithosphere-asthenosphere boundary

Alexander V. Grayver1,*, Neesha R. Schnepf2, Alexey V. Kuvshinov1, Terence J. Sabaka3, Chandrasekharan Manoj4 and Nils Olsen5

- Author Affiliations

1Institute of Geophysics, ETH Zürich, Sonneggstrasse 5, Zürich, Switzerland.

2Department of Geological Sciences/Cooperative Institute for Research In Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80305–3337, USA.

3Planetary Geodynamics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD, USA.

4National Oceanic and Atmospheric Administration’s National Centers for Environmental Information/CIRES, University of Colorado, Boulder, CO 80305–3328, USA.

5DTU Space, Lyngby, Denmark.

↵*Corresponding author. Email: agrayver@erdw.ethz.ch

Science Advances 30 Sep 2016: Vol. 2, no. 9, e1600798

Credit/Crédito: ESA/ATG medialab


The tidal flow of electrically conductive oceans through the geomagnetic field results in the generation of secondary magnetic signals, which provide information on the subsurface structure. Data from the new generation of satellites were shown to contain magnetic signals due to tidal flow; however, there are no reports that these signals have been used to infer subsurface structure. We use satellite-detected tidal magnetic fields to image the global electrical structure of the oceanic lithosphere and upper mantle down to a depth of about 250 km. The model derived from more than 12 years of satellite data reveals a ≈72-km-thick upper resistive layer followed by a sharp increase in electrical conductivity likely associated with the lithosphere-asthenosphere boundary, which separates colder rigid oceanic plates from the ductile and hotter asthenosphere.

Keywords Oceans tidal flow magnetic signals lithosphere-asthenospere satellite

Copyright © 2016, The Authors

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.

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