Probing Earth’s Deep Interior using Space Observations Synergistically

New special issue in Surveys in Geophysics (all papers open access)

During the last two decades, the GRACE and SWARM space missions have provided a wealth of groundbreaking results about the spatio-temporally variable gravity and geomagnetic fields of the Earth. However, more can be learned about the deep Earth’s structure by combining data of the Earth’s gravity and magnetic fields together with Earth’s rotation data routinely measured using space geodesy techniques, such as Very Long Baseline Interferometry (VLBI). The synergistic use of these three observables represents a unique way to investigate the physics of the deep Earth’s interior. In addition to the well-known correlation between the Earth’s rotation and magnetic field observed at the decadal time scale, recent studies have reported an unexpected correlation between spatio-temporal changes of the gravity field and of the magnetic field, also at the decadal time scale. Processes occurring in the liquid core and at the core–mantle boundary (CMB) are potentially responsible for this observation. The Workshop “Probing the Deep Earth Interior by using in synergy observations of the Earth’s gravity and magnetic fields, and of the Earth’s rotation” held at the International Space Science Institute (ISSI, Bern) on 1–4 September 2020, gathered about 40 scientists from different horizons and expertise to discuss this novel research topic. The different sessions successively addressed the capability of the gravity and magnetic fields, and Earth rotation observations to detect deep Earth signals on interannual time scales, the current knowledge of processes occurring in the fluid outer core, at the CMB and within the lower mantle, as well as the present-day status of theoretical models describing the deep Earth structure.

This Special Issue gathers together overview articles that provide state-of-the-art knowledge on the various aspects of this emergent research area. It addresses different timescales associated with these deep Earth observed signals as well as associated modeling aspects.

This special issue will be reprinted as as the Volume 85 in the Space Science Series of ISSI and is edited by Veronique Dehant, Mioara Mandea, Anny Cazenave and Lorena Moreira.