Ice sublimation as a geomorphic process: A planetary perspective

Sinuous Rille

“…Volatiles ice removed from dark regions are redeposited onto clean ice as frost. This process enhances albedo contrast between dirty and clean ice (Prockter et al 1998;Mangold 2011). This process characteristically occurs on icy satellite surfaces and on the Martian polar caps.…”

“…Terrestrial sand sheets can be divided into (1.1) warm and (1.2) cold climate classes, with the main distinction being sediment sources and their relation to other aeolian bedforms. Cold climate sand sheets in northern Europe, North America, Russia, and Iceland have a greater proportion of glacial and fluvioglacial sediments than the warm climate variety and are rarely found near duneforms (Pye and Tsoar 1990;Mangold et al 2011). (2) Stringer/streak (▶ streamer): sand sheet of elongate stringer-like shape, typically developing along the margins or at the downwind extremity of a sheet; it has no slip face (McKee 1979; see also ▶ Zibar).…”

Radar-bright Spot

“…This term is sometimes used in broad sense for all depressions in the south polar residual cap; the use of this term in this sense is discouraged (Thomas et al 2009). "Swiss cheese terrain" does not capture the full range of morphologies of the depressions, including long, sinuous ones (Mangold 2011); the large circular depressions are not even the "typical" form among the south polar residual cap features (Thomas 2003); more than 99 % of the residual cap does not have circular depressions (Thomas et al 2009 …”

“…(2) An older unit (A) 8-14 m in thickness. Its upper surface is polygonally patterned and is expressed as mesas or broad surfaces and is embayed by 200-1,000 m wide circular to curled to sinuous depressions that tend to align in north-south directions, which is indicative of their relation to insolation(Mangold 2011 and references therein, Thomas 2003; Thomas et al 2009). This unit accounts for 3 % the volume of the residual cap.…”

Ghost Crater

“…Eroded craters may appear as rimless cavities. (3) Deformed ghost crater: Progressive degradation of impact craters in ice-rich material leads to ghost crater morphologies (Mangold 2011) due to sublimation of ice or viscous relaxation of icy regolith (▶ softened crater, ▶ deformed crater (viscous flow), ▶ palimpsest). (4) Epigenetic ghost crater: Defined by subsequently formed landforms over the buried crater rim.…”