Blood Falls

When I think of Antarctica in color, I think about white, blue, cerulean, azure, grey, brown, and occasionally black (orcas, penguins). There is a feature on the terminus of the Taylor Glacier called Blood Falls. It is a surprising rusty red color. Blood Falls is not very well understood, but there are some theories about why it is there. Today my friend Jill and I went to collect some samples and talk about her research a little more. Jill is a microbiologist and I am a geochemist. Even though we have different interests, we both think that Blood Falls is fascinating.
People have been curious about Blood Falls since it was first observed by Scott's party in 1903. They noted in their journal that the terminus of the glacier had a red color that they thought might be from algae. Scientists who have seen the site since then have been surprised by it and several have studied it.

The water that gets discharged from the top of the terminus is very salty, similar to the salinity of seawater, but the chemical composition is a little different. It is also anoxic, meaning that it does not contain any dissolved oxygen. It also has high concentrations of iron in reduced form. Once the water works its way out onto the top of the glacier and flows down, it is exposed to light and oxygen and the dissolved iron starts to oxidize... just like that bicycle you left outside. Jill studies the bacteria that live in the water. I am interested in the chemistry. We both want to know why it's there, how often it discharges, why it is anoxic, where the iron comes from, why it is salty, whether the bacteria are thriving or just surviving. We have answers to some of those questions. But that's the exciting thing about science, there is always more to know. It is about adding pieces to an ever expanding puzzle.