This global tectonic map was created by researchers from Kiel University and the British Antarctic Survey using gravity gradients – the rate of change in the pull of gravity in different directions – measured by ESA’s GOCE gravity-mapping satellite. These gravity gradients were used to create a curvature-based shape index, analogous to contour lines on a map, which can be interpreted as a tectonic map of the Earth, as seen by GOCE. Surface topography is stripped away to reveal the deep structure of the continents and oceans. Geological similar tectonic domains can exhibit distinct differences in satellite gravity gradients maps, which point to differences in the lithosphere – the solid crust and the molten mantle beneath. In combination with seismological results, gravity-gradient imaging offers a new window on Earth’s structure. In this project, for the first time, seismological models and satellite observations are integrated to provide a consistent image of the crust and upper mantle in 3D, needed to understand the coupling of plate tectonics and mantle dynamics. In remote frontiers like the Antarctic continent, where even basic knowledge of lithospheric scale features remains incomplete, the curvature images help unveil the heterogeneity in lithospheric structure, e.g. between the composite East Antarctic Craton and the West Antarctic Rift System.
Read full story: ESA’s gravity-mapper reveals relics of ancient continents under Antarctic ice