Speaker
Dr
Klára Kalousová
(Charles University, Faculty of Mathematics and Physics, Department of Geophysics)
Description
The exploration of ocean worlds - planets or moons that harbor deep subsurface oceans - is prompted by the question of the emergence of life in places where liquid water is present. Measurements performed by the Galileo and Cassini missions confirmed the presence of these deep oceans within the interiors of some Jovian and Saturnian moons. A lot of attention is currently given to smaller moons (Europa and Enceladus) where the deep ocean is expected to be in a direct contact with the underlying silicate mantle – such conditions are similar to those at terrestrial sea floors where life develops. Ganymede, the largest moon in the solar system, possesses a larger amount of H2O so that a layer of high-pressure (HP) ice exists in its interior that seems to prevent the direct contact of water with silicates. We study the dynamics of this HP ice layer by solving the conservation equations of mass, momentum, and energy of a two-phase mixture by the finite element method. Our results indicate that melt can be produced at the silicate/HP ice interface and then transported through the layer by the upwelling plumes. Depending on the vigor of convection, it may stay liquid or freeze before melting again as the plume reaches the partially molten layer at the top boundary from where it is extracted into the ocean. Our results also suggest that these exchange processes were more likely earlier in Ganymede's history, when the HP ice layer was thinner.
Primary author
Dr
Klára Kalousová
(Charles University, Faculty of Mathematics and Physics, Department of Geophysics)
