Subglacial lakes that never see the light of day are among the least accessible frontiers of science, brimming with more tales yet untold than even the planets of our solar system. One thing seems certain: where there is water, there is life -- even if said water is at the bottom of a frigid lake, in pitch darkness, below more than a half mile of the West Antarctic Ice Sheet.
As reported in AGU Advances, scientists analyzed the chemical fingerprint of the ocean and microbes retrieved from sediments and water at the bottom of a subglacial lake called Mercer Lake to describe, for the first time, where the feisty microbes get carbon, the energy source du jour, and move it through this fiercely desolate system. They used the data from the sediment, microbes, and the carbon cycle to infer the geologic history of this region, and the results surprised them.
While they previously thought that the ice over Mercer Lake had been stable for up to hundreds of millennia, this new work confirms the lake was connected to the ocean about 6,000 years ago, and the West Antarctic Ice Sheet was smaller than it is today. This was a period when climate was stable relative to the end of the last ice age and even to today’s anthropogenic climate change.
Read more at University of South Florida
Image: Surprising results from historic study suggest the shrinking West Antarctic Ice Sheet, a major threat to global sea level rise, was smaller and more dynamic in recent geologic past than previously thought. (Credit: Ryan Venturelli)