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Holtedahl Mountain Campaign

Holtedahl Mountain Campaign

December 2024 – January 2025

This season, a team of six SAEF scientists from Monash University and the University of Tasmania will travel to the Hotedahl Mountains in the Queen Maud Land region of Antarctica to study how the history of the ice has influenced the survival of life. The team will be supported by White Desert.

 

Can we uncover 1 million years of ice sheet change?

The Hotedahl Peaks in Queen Maud Land seem to have been above the ice surface for 1 – 4 million years, but it’s unclear how dynamic the ice is. At what points was the ice retreating, stable, and/or advancing, and what were the associated climatic conditions? Understanding the stability of this region relative to elsewhere in Antarctica provides an extraordinary opportunity to understand change across the continent.

The SAEF glaciology team, Professor Andrew Mackintosh and Dr Levan Tielidze, will primarily conduct fieldwork on the nunataks of the Holtedahl Peaks. These ice-free mountain summits tower above the surrounding ice and offer rock samples that record glacier thickness changes. These rock samples act as stopwatches, recording the time since they were uncovered via the accumulation of cosmogenic nuclides (chemical signals produced within the rock’s quartz by cosmic rays from outer space). By understanding the concentration of cosmogenic nuclides in samples at different elevations, the team can understand how the ice has changed over time.

 

How has this record of ice change found its way into life?

Nuntaks are sometimes called “islands in the ice” because they can be hotspots for Antarctic biodiversity. Nunataks are home to the region’s tiniest life in many parts of the continent, such as microbes, invertebrates, moss, and lichen. In other places, there is no life at all.

The SAEF biodiversity team will search for life on these nunataks. They’ll aim to collect data and samples that will enable them to sequence life’s building blocks (DNA and RNA) to understand how long the nunataks have been colonised by life and separated from each other.

  • Microbes: Dr Sophie Holland will collect soil samples and conduct in-field experiments to study the microbes that live in the soil to identify what species live there (taxonomic diversity) and what they can do (functional diversity). They are particularly interested in bacteria that can “live on air” or use trace atmospheric gases, such as hydrogen, as fuel to meet their energy needs.
  • O Springtail, Where Art Thou? Rebecca Hallas and Naomi Monk will search for springtails, tiny invertebrates that are 1 – 3 mm long and can jump considerable distances when disturbed due to the tiny spring beneath their abdomen. Comparing where springtails are and aren’t found, with reconstructions of how the ice has advanced and retreated over millennia, will help understand how Antarctic life has evolved as the environment and climate have changed around it. Understanding this is key to predicting how it will respond in the future and developing conservation plans to manage those impacts. This fieldwork involves spending hours and hours with face to the ground, looking for tiny movements. The search is directed to areas with water, moss, algae or lichen, which offer food and habitat. The team will flip over flat rocks and stare intently into water samples to see if anything jumps or floats!
  • Antarctic Moss: Moss is one of the few plants that grows in Antarctica. It provides a habitat for tiny organisms and has incredible adaptations that allow it to survive yearly freezing and thawing cycles. The team will collect moss samples for radiocarbon dating of their annual growth layers. Moss shoots growing in Antarctica can be hundreds of years old and hold an important local climate record within their cells. They offer a climate proxy for ice-free areas of Antarctica where the local climate can be very different from ice-covered areas, differing from ice cores. The fieldwork involves looking for little patches of green or black and collecting tiny moss “cores” for dating.

 

Coupled with the work of the glaciology team, this information provides a picture of how the ice has come and gone in the region and how it has influenced life in the region. The DNA in the life and cosmogenic nuclides in the rocks can tell us the history of the ice, and this history can help forecast the future: a future with less ice.

 

The team

  • Professor Andrew Mackintosh (Monash University)
  • Dr Sophie Holland (Monash University)
  • Dr Levan Tielidze (Monash University)
  • Dr Ian Kelly (University of Tasmania)
  • Rebecca Hallas (Monash University)
  • Naomi Monk (Monash University)

 

This expedition is facilitated by White Desert, through their science logistics program

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