January 18, 2014
Blood falls is a bright red waterfall of iron oxide-rich water that streams through Taylor glacier into Lake Bonnie in the McMurdo Dry Valleys. Two of the streams that we measure empty into Lake Bonnie, so we’re able to visit Blood Falls every two weeks or so, and the view of the color red in the otherwise brown, blue, and white Dry Valleys is a surprising sight.
While a lot of the glaciers in the Dry Valleys have waterfalls that release meltwater through channels along and under the glaciers, Blood Falls is unique because the water comes from an iron-rich hypersaline (extra-salty) subglacial lake underneath Taylor glacier; a lake of ancient seawater that became trapped under the glacier approximately two million years ago. Meltwater pushes some of the hyper-saline lake water through the side of the glacier and mixes with oxygen in the air to develop the rusty color of the water and ice.
This waterfall was first described by Thomas Griffith Taylor, the expedition geologist on Robert Scott’s 1911 expedition in the Antarctic. Scott named both the glacier and the entire valley between the Asgard mountains and Kukri Hills (where I live and where my photos of F6 camp come from) after Taylor, and it is the most Southern of the three large McMurdo Dry Valleys. The Taylor glacier once carved the entire valley in between these mountains and reached out towards the ocean, but it has been receding and its edge is now 18 miles away from the Antarctic coast.
More than 17 types of microbes have been discovered living in the subglacial anoxic lake (anoxic water contains no free oxygen), and a team of scientists this season have been devising an experiment to drill into the glacier and see what sort of other organisms might be able to survive in those conditions. It’s a difficult job to study anoxic systems because as soon as you drill through the glacier, you would be exposing the environment to oxygen that it has never seen before, instantly changing the conditions you wanted to study. Research on anoxic systems is important in the field of astrobiology, making comparisons between unique oxygen-deprived systems on Earth and the sorts of biological life that might be possible on other planets where oxygen is also absent and organisms need to develop other methods to survive.
In the past few weeks our team has been busy measuring and sampling the meltwater from all of the creeks and streams in the valleys. This season has officially been declared a ‘high flow’ year because water levels have reached unusually high levels, but now in the middle of January, we’re getting farther away from the peak of austral summer and the meltwater should slow down soon. I’ve been lucky enough to take a few trips up to different glaciers to collect meltwater for my research, so in addition to all of the ground-level views of mountains from the creeks that we study, now I’ve been able to see what the Transantarctic mountains look like from higher up on the glaciers and peaks. I’ll update with photos and more descriptions soon!