Antarctica

Antarctica hosts the largest ice sheets on Earth, and 98% of the continent is buried underneath. The lithospheric structure is however still poorly explored. Robust knowledge of the interior is essential to understand the Earth’s response to ice mass changes (glacial isostatic adjustment).

Of particular interest are the depth and geometry of the main subsurface boundaries (Pappa et al., 2019), which are the interface between crustal and mantle rocks (Moho discontinuity) and the base of the rigid tectonic plate (lithosphere). Since both of them are accompanied by changes in rock density, we used gravimetric data from the GOCE satellite to build a 3D model of Antarctica’s deep structure. By also taking into account the rock composition according to temperature and pressure, the model is internally consistent, which helps to compensate the scarcity of robust ground and airborne data in Antarctica. From the temperature distribution in our model, we derive present-day solid Earth’s behavior due to glacial isostatic adjustment, one of the most significant uncertainties when assessing present-day ice sheet mass change from satellite studies.

 

A new Moho depth map of the Antarctic continent based on satellite gravity gradient data. In areas that are covered by seismic stations, our estimates match the seismological crustal thickness assessments to a large extent. Previously under-explored regions of East Antarctica are now mapped in unprecedented detail. ASB=Aurora Subglacial Basin, DML=Dronning Maud Land, EL=Enderby Land, GSM=Gamburtsev Subglacial Mountains, IAAS=Indo-Australo-Antarctic Suture, LG=Lambert Graben, TAC=Terre Adélie Craton, TAM=Transantarctic Mountains, VD=Valkyrie Dome, WSB=Wilkes Subglacial Basin.