Glaciers, those immense masses or rivers of ice that run down the slopes of the mountains in the coldest areas of the planet, basically contain water. However, some of them also carry a good number of rocks and minerals that can alter their appearance, usually bluish white . For example, in Antarctica there is a place watered by reddish torrents known as blood falls.
This crimson fluid emerges from an open wound from the bowels of the Taylor Glacier, named in honor of the Australian geographer and explorer Thomas Griffith Taylor, a member of Scott’s expedition to the South Pole of 1911. He was the first to admire this unique landscape. in the Antarctic region of the McMurdo Dry Valleys, which make up one of the driest areas in the world. There is hardly any rainfall there and the absence of ice in some places reveals a desert terrain. The structure of the glacier, which is 54 kilometers long and 400 meters thick, is not totally frozen.
The solid part rides on a lake whose waters have a concentration of salt four times higher than that of the oceans, in addition to a lot of iron. Initially the scientists who investigated this phenomenon thought that the red color came from a population of algae, but the truth is that it is due to the abundance of the metal: when the liquid goes outside, the ferrous ion oxidizes on contact with the atmosphere , and its oxides – not very soluble – are deposited on the surface.
The underlying brine zone is between 1.5 and 2 million years old and is home to a rich ecosystem of autotrophic bacteria that metabolize sulfur and iron ions. University of Tennessee microbiologist Jill Mikucki was responsible for the find. According to laboratory analysis, these microscopic organisms use sulfate as a catalyst in respiration, take iron in its ferric form –insoluble– and transform it into ferrous –soluble in water– using organic matter buried next to them as an energy source.
Mikucki and his team were the first to observe the phenomenon in nature. Due to their isolation, microorganisms would have evolved outside the outside, differentiating themselves from similar bacteria that inhabit the oceans.
Image: COURTESY PETER REJCEK NATIONAL SCIENCE FOUNDATION
