title: Satellite tidal magnetic signals constrain oceanic lithosphere-asthenosphere boundary.
abstract: 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.
authors.affiliation: Institute of Geophysics, ETH Zürich, Sonneggstrasse 5, Zürich, Switzerland.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Grayver
authors.affiliation: Department of Geological Sciences/Cooperative Institute for Research In Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80305-3337, USA.
authors.forename: Neesha R
authors.identifier: 0000-0003-1489-7958
authors.initials: NR
authors.lastname: Schnepf
authors.affiliation: Institute of Geophysics, ETH Zürich, Sonneggstrasse 5, Zürich, Switzerland.
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Kuvshinov
authors.affiliation: Planetary Geodynamics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD, USA.
authors.forename: Terence J
authors.initials: TJ
authors.lastname: Sabaka
authors.affiliation: National Oceanic and Atmospheric Administration's National Centers for Environmental Information/CIRES, University of Colorado, Boulder, CO 80305-3328, USA.
authors.forename: Chandrasekharan
authors.initials: C
authors.lastname: Manoj
authors.affiliation: DTU Space, Lyngby, Denmark.
authors.forename: Nils
authors.identifier: 0000-0003-1132-6113
authors.initials: N
authors.lastname: Olsen
mesh_terms: D055593:Geological Phenomena; D060526:Magnetic Fields; D009792:Oceans and Seas; D017215:Satellite Communications; D055871:Tidal Waves
keywords: Oceans; lithosphere-asthenospere; magnetic signals; satellite; tidal flow