Dale Andersen’s Astrobiology Antarctic Research: Permafrost And Ground-ice Conditions in the Untersee Oasis, Queen Maud Land, East Antarctica (Paper)
Keith’s note: Astrobiologist Dale Andersen is back in Antarctica at Lake Untersee in October-December 2024 for another field season of research (preview). Dale’s work is coordinated through the SETI Institute. We’ll be posting his updates here. You can read about his prior exploits from this field season and past field seasons here. Knowledge of Antarctic permafrost is mainly derived from the Antarctic Peninsula and Victoria Land. This study examines the 2019–2023 temperature and humidity conditions, distribution and development of polygonal terrain and the origin of ground ice in soils of the Untersee Oasis. This paper is part of the ongoing published research that has resulted from this multi-year exploration of the Untersee Oasis – an analog for conditions that we will find on Mars and other worlds when we conduct astrobiology expeditions to these worlds.
In this region, the surface offset (MAAT ≅ MAGST) and the thermal offset (MAGST ≤ TTIT) reflect the lack of vegetation, absence of persistent snow and a dry soil above the ice table.
Map showing the distribution of polygonal terrain in Pritzker Valley, Untersee Oasis. b. & c. Field photographs (December 2021) of Pritzker Valley. — Cambridge Core
The mean annual vapour pressure at the ground surface is approximately ~2× higher than in the air but is ~0.67× lower than at the ice table.
The size of polygons appears to be in equilibrium with the ice-table depth, and numerical modelling suggests that the depth of the ice table is in turn in equilibrium with the ground surface temperature and humidity.
The ground ice at the ice table probably originates from the partial evaporation of snowmelt that infiltrated the dry soil column. As such, the depth of the ice table in this region is set by the water vapour density gradient between the ground surface and the ice-bearing ground, but it is recharged periodically by evaporating snowmelt.
Location of sites in the Untersee Oasis, Queen Maud Land, Antarctica. Background Digital Globe NextView satellite imagery, 7 December 2017; ©2020 Digital Globe NextView License (provided by NGA commercial imagery program). — Cambridge Core
Field photographs of the polygonal terrain developing over buried glacial ice along the western lateral moraine of the Anuchin Glacier in the Untersee Oasis. d. & e. Field photographs showing the development of sublimation-type sand-wedge polygons. — Cambridge Core
Denis Lacelle, Marjolaine Verret, Benoit Faucher, David Fisher, Adam Gaudreau, André Pellerin, Miles Ecclestone, and Dale T. Andersen
Permafrost and ground-ice conditions in the Untersee Oasis, Queen Maud Land, East Antarctica, Cambridge Core (open access)
Related links.
2024 Preview: Dale Andersen’s Field Report: Preview: 2024 Lake Untersee Field Season
Keith: Dale and I have been proving research updates – from Antarctica – since 1996. We think we actually had the first webserver (located in my old condo) updated from Antarctica. More details here: Dale Andersen’s 1996 Antarctic Field Research Photo Albums
AstrobiologyAstrobiology
