What Are They Doing?
Are microorganisms metabolically active in glacier ice? To address this exciting question, the research team traveled to the McMurdo Dry Valleys – one of the harshest environments on Earth – to study the biology, geology, and chemistry of basal ice – the dynamic layer of ice closest to the bedrock at the base of a glacier. The team used a tunnel cut into the side of Taylor Glacier to reach the basal ice layer. Data collected from field measurements and laboratory experiments helped researchers understand the connections between available nutrients, geochemical properties, and gas composition. This information helped determine if evidence for metabolism of microorganisms living in the ice could be found, and to link this to the types of cells present.
In addition, the research team investigated the similarities and differences among microorganisms in different types of ice within the basal ice zone. Some layers in the basal ice zone are clear and have little sediment. Other layers have high concentrations of debris. The basal ice zones of polar glaciers show similarities with the layered deposits evident in images of the northern ice cap on Mars. The findings from this project may be of interest to scientists studying potential habitats for microbial life on Mars and on the survival in of microorganisms in ice because the frozen environments in Antarctica and Mars may have many similarities.
Where Are They?
The team camped on the shore of Lake Bonney, a permanently frozen saline lake in the McMurdo Dry Valleys of Antarctica. The McMurdo Dry Valleys are located on the western coast of McMurdo Sound (77°00'S 162°52'E) and form the largest relatively ice-free area (approximately 4,800 square kilometers) on the continent. The perennially ice-covered lakes, frozen alpine glaciers, and extensive areas of exposed soil and permafrost within the McMurdo Dry Valleys are subject to low temperatures, limited snowfall, and salt accumulation. Lake Bonney is also the terminus of Taylor Glacier, where the team conducted fieldwork in an ice tunnel they carved using chainsaws.
Mark Skidmore is an assistant professor of geology at Montana State University. Dr. Skidmore’s field research takes him to glaciers in Antarctica, the Swiss Alps, Alaska, the Yukon, Iceland, and Washington. He also conducts low temperature laboratory studies of microbial activity at near freezing temperatures. His current research focuses on the biogeochemical cycling and geomicrobiology of glacier systems and biogeochemical processes associated with geologic carbon dioxide (CO2) sequestration.