Sledding 2500+ km across Antarctica
By: Catherine Maggiori
Synopsis: In this article, we talk about a sled-based expedition across the East Antarctic Plateau and how it led to the discovery and cultivation of a new Cyanobacterial species.
Author info: Dr. Catherine Maggiori is an astrobiologist and microbiologist. You can find her writing about science, attempting to set up a Bluesky account, or at the climbing gym.
Article: Microbial biogeography along a 2578 km transect on the East Antarctic Plateau
It’s deep into summertime here in Washington, DC, at the time I’m writing this. A heat bubble is encapsulating much of the Eastern United States right now, so naturally I’m dreaming about all of the wintertime activities I can’t do.
What kinds of things do you like to do in the cold weather? Skiing? Snowshoeing? Reading by a crackling fire?
What about sledding?
It may not have been in the conventional sense, but that’s what Parro and coauthors did for this article, “Microbial biogeography along a 2578 km transect on the East Antarctic Plateau,” in Nature Communications: they went sledding.
Traversing the East Antarctic Plateau in WindSled, a mobile sled+kite hybrid platform, Parro et al. investigated the geochemical and geographic distribution of microbial communities in the air and snow.
The WindSled traversing Antarctica during 2018 - 2019. Spot the kite in the top left of this image!
The WindSled, aka the Inuit WindSled, was originally designed by Ramón Larramendi and is a zero-emission polar vehicle that combines traditional Inuit technology with large kites to harness wind power for transportation. The sled is modular and articulated, able to include as many platforms as necessary and overlain with tents and cargo as needed.
Check out the WindSled in action:
The WindSled has travelled across Greenland, the Canadian Arctic, Alaska, and Antarctica, including reaching the Geographic South Pole, circumnavigating Greenland’s South Dome, and use in research missions like the Dark Snow Project and the present study.
The Antarctic Plateau is one of the most extreme, remote environments on Earth; indeed, the lowest ever temperature recorded on Earth (-89.2 ℃) was from Vostok Station. Characterized by freezing temperatures and hyper-aridity, it’s an extremely strong analogue to Mars and naturally houses microbial communities specialized to survive in this harsh, unforgiving landscape.
Snow and ice on the plateau can serve as climatic and atmospheric archives, but studies of their microbiology have been scarce and are typically confined to surface snow (down to ~30 cm) or subglacial lakes accessible from coastal research stations.
Getting a better picture of Antarctica’s microbiology involves travelling long distances with scientific personnel and equipment across Antarctica. Antarctic exploration and field work involves all the logistical difficulties of regular polar field work with the added complication of not being able to use sled dogs, as they are forbidden in Antarctica since 1994. The WindSled helps mitigate some of these technical challenges by requiring little logistical support and having a small environmental impact, allowing researchers to study previously inaccessible landscapes and gradients.
Fig. 1 from Parro et al. showing: A) WindSled travel path and sample sites; B) the WindSled; C) drill coring system; D) airborne aerosol collector; E) air parcel trajectories.
Using the WindSled, Parro and coauthors were able to examine microbial communities from both air (1.5 m height) and snow/ice down to 4 m depth at 3 separate locations along a 2578 km longitudinal transect across the East Antarctic Plateau.
From Fig. 4 of Parro et al. showing the 16S community composition in the three air (AN, AM, AS) and three snow/ice cores (DN, DM, DS).
In the snow/ice cores, microorganisms were found widely distributed through the ice down to at least 4 m, capturing a biosphere that spans several decades buried within ice layers. The snow and ice samples also contained greater bacterial diversity than the air samples, with between 84 and 359 unique ASVs per sample vs. 9 to 33 in air samples. Firmicutes and Actinobacteriota dominated most cores, although Proteobacteria and Cyanobacteria were abundant in certain deep samples, including as a newly isolated species (Gloeocapsopsis sp. CAB1).
Fig. 5 from Parro et al. showing: A) micrograph of Gloeocapsopsis sp. CAB1 cells; B) Phycobiliproteins and chlorophyll autofluorescence of Gloeocapsopsis sp. CAB1 cells; C) maximum likelihood phylogenetic tree placing this new species as a member of the Gloeocapsopsis genus.
Microbial distributions are associated with wind trajectory and speed, suggesting that airborne dispersal, snow drifting, and snow accumulation shape the biogeography of Antarctic microbes. Over time, reservoir effects and environmental selection appear to favor organisms adapted to the persistent hyper-arid, hypothermal conditions in the East Antarctic Plateau.
As a strong Mars analogue, the presence of viable microbial communities in the East Antarctic Plateau at near-permafrost depths pushes the known limits of life and can inform on the potential habitability of large icy areas on Mars, thanks to WindSled’s zero-emission, mobile lab.