This week at Macquarie Island: 2 February 2018

It’s February already, which means we have less than six weeks before the arrival of the resupply ship Aurora Australis, marking the end of our season!

With resupply fast approaching, our busy work tempo continues. In the coming weeks, our three summer season science projects (Albatross & Giant Petrels, Post Eradication Response, and Lake Coring) will be embarking on multiple field trips, as they look to maximise the remaining season time to achieve their project results.

For station-based support expeditioners, it will also be a busy period preparing their respective workplaces for handover to the incoming season’s expeditioners, as well as organising and preparing cargo for return to Australia.

In between these activities, we have been busy with our regular Search and Rescue (SAR) training. This culminated late last week in completion of a major SAR technical rescue training exercise. Led by our Senior Field Training Officer Mark, the multi-stage exercise involved a field-based search for an injured expeditioner, with a subsequent evacuation from a steep slope using a rope rescue system and stretcher carry. We’ll report on this training exercise in more detail in forthcoming station news, but suffice to say it was a great success!

Finally, last Friday saw us all celebrate Australia Day. Our fun-filled day included a traditional swim in the chilly sub-Antarctic waters, followed by a hot spa, and then enjoying some traditional Australia Day food throughout the day including lamingtons, pies, and a BBQ.  A great day was had by all!

By Kyle (Station Leader).

For the second half of summer on Macquarie Island, researchers will be battling with the Furious Fifties to unlock secrets about the Island’s past.

The plateau of Macquarie Island is scattered with dozens of lakes and tarns. These water bodies are important ‘history books’ of the area’s climate and environment. Every year, a new page is written as a thin layer of sediment is deposited onto the bottom of the lake. Each sediment layer is a snap shot of the local environmental conditions within and around the lake. Species of diatoms (small single-cell plants) trapped in sediment layers tell us about former salinity levels in the lakes. This information gives us an indication of the strength of the predominant winds in this region. Westerly winds blow sea spray across the island depositing salt into the lakes, thus the stronger the winds the higher the salinity. In time, these sediment layers accumulate into a long history of the region’s past environmental conditions.

Equipped with inflatable boats and an adventurous spirit, researchers aim to uncover this trapped history. From aboard their rafts using ‘gravity corers’ researchers will collect ‘sediment cores’, tubes of mud containing thousands of years of information. Back in the lab, different techniques will be used to ‘read’ each sediment layer. This information, bolstered by an extensive water chemistry and diatom study across the island, will give us an insight into past climates at Macquarie Island and changes in westerly wind strengths. Understanding relationships between changes in climate and the strength of winds in this region is important to understand current global climate and predict future changes, especially as these winds affect how much carbon is absorbed or released by the Southern Ocean.

Kristen & Aimee (Research Assistants)