Meltwaters home to harsh ecosystem

There is nothing like -10degC in the middle of summer to remind you that Dunedin’s summer is really not that bad.

University of Otago geography PhD students Marte Hofsteenge and Tamara Pletzer have recently returned from the Antarctic, where they have been researching the McMurdo Dry Valleys.

There are no plants, birds or mammals in the area, but microbes and microscopic soil invertebrates do live in the harsh ecosystem, where the mean average temperature is below -15degC.

Miss Hofsteenge said they spent six weeks conducting field research as part of the Antarctic Science Platform-funded efforts to determine the role of meltwater in the Ross Sea region, which harbours diverse land-based ecosystems ranging from Antarctic lakes to ancient soils that house many unique biota.

"In our PhD research, we’re attempting to model the meltwater from these glaciers, since it is so important for the survival of the ecosystem.

"A lot of our fieldwork was focused on gathering data to evaluate our models.

"This year we maintained an automatic weather station on Commonwealth Glacier, which measures temperature and wind speed over the full year.

"We also collected sensors that measured soil temperatures over winter, which were still working after experiencing temperatures down to -40degC."

Miss Pletzer said working in such cold temperatures could be unpleasant, especially when it was windy and the wind-chill factor dropped temperatures to as low as -20degC.

But the views quickly made them forget about the cold.

"The temperatures make you realise how good summer is in Dunedin.

"It was around zero degC most of the time and it’s quite a dry environment.

"It’s a really interesting area because it looks different to what people imagine when they think of Antarctica.

"There’s a lot of rock and sand on the ground, but then there’s all these big mountains and glaciers feeding into the valleys, and all the glaciers have big 20m-30m cliffs around them.

"So it is quite a spectacular place to do field work. The midnight sun is amazing."

The duo said it was a "privilege" to be able to visit and do research on the icy continent.

Miss Hofsteenge said they were now back in the office, looking into the data they had collected in the field, and were comparing their models with what actually happened.

"This will allow us to better understand other glaciers in the McMurdo Dry Valleys, where we don’t have automatic weather stations."

john.lewis@odt.co.nz