Video: Ice coverage, bedrock topography, Moho depth, and lithospheric thickness of Antarctica. The colours represent temperatures in the lithosphere based on our modelling. Note the strong contrast between thin and warm West Antarctica (left) and thick and cold East Antarctica (right).

 

The hereby established lithospheric structure and temperature model also serves as an input for geodynamic modelling, investigating the plausibility of a mantle plume in West Antarctica - a hypothesis that has been discussed interdisciplinary for more than 30 years. In particular, we use the mantle convection code ASPECT to estimate the impact of a potential plume ponding beneath the lithosphere on the surface heat flux beneath the ice sheet. Testing various plume parameters, our reference plume model influences the lithosphere-asthenosphere boundary (LAB) over a distance of about 1000 km and generates an uplift of maximum 25 km, in agreement with previous plume models (e.g. Bredow et al., 2017).

 

Lithosphere thickness with thermal anomaly beneath central Marie Byrd Land, simulating a potential plume beneath West Antarctica (a) and the effect of the plume on the LAB in a vertical cross-section (b).

The regional case studies of Antarctica are continuously compared and reconciled with the global reference model established in the course of the 3D Earth project. We will also further exploit the new airborne compilation ADMAP2.0 to fill the polar map present in satellite data. Moreover, this lithospheric model of Antarctica will be used as a background model for the inversion of aero gravity data in order to delineate different geological regions beneath the ice coverage.