Ground ice in the martian regolith

Abstract

The long-term existence of extremely cold climate on Mars has led to strong global freezing through upper layers of the planet’s crust that has resulted in formation of the global permafrost shell - cryolithosphere. In accordance with the modern thermal regime of the Martian surface and the reasonable values of the planet’s heat flow, the thickness of the cryolithosphere may approach 1-2 km in the equatorial zone and 5-6 km in the polar regions. In the presence of such a huge scale of cryolithosphere, most of the Martian water abundance could be captured primarily within the permafrost shell in the form of ground ice and possibly salt solutions. It is not excluded that some amount of the liquid and solid phases of CO 2 (plus clathrate) may also be contained in the cryolithosphere.