Electrical conductivity of the Earth's mantle from the first Swarm magnetic field measurements. Issue 9 (7th May 2015)

• Record Type: Journal Article
• Authors: Civet, F.; Thébault, E.; Verhoeven, O.; Langlais, B.; Saturnino, D.
• Is Part Of: Geophysical research letters. Volume 42:Issue 9(2015:May)
• Page Start: 3338
• Page End: 3346
• Publication Date: 2015-05-07
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2015GL063397
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main" id="grl52817-abs-0001"> <title>Abstract</title> <p id="grl52817-para-0001">We present a 1‐D electrical conductivity profile of the Earth's mantle down to 2000 km derived from L1b Swarm satellite magnetic field measurements from November 2013 to September 2014. We first derive a model for the main magnetic field, correct the data for a lithospheric field model, and additionally select the data to reduce the contributions of the ionospheric field. We then model the primary and induced magnetospheric fields for periods between 2 and 256 days and perform a Bayesian inversion to obtain the probability density function for the electrical conductivity as function of depth. The conductivity increases by 3 orders of magnitude in the 400–900 km depth range. Assuming a pyrolitic mantle composition, this profile is interpreted in terms of temperature variations leading to a temperature gradient in the lower mantle that is close to adiabatic.</p> </abstract>