Lake Ellsworth: Evidence of Past Climates
The Lake Ellsworth study has a further, potentially far-reaching, significance. One its key aims is to drill through the ice and take a sediment core from the lake bed which, according to the expedition’s website, will ‘uncover a record of past ice and climate conditions in West Antarctica – critical for assessing the present-day risk of ice sheet collapse, and consequent sea-level rise.’
Describing this in more detail, Dr. Ross explained that the topography suggests that, prior to the formation of the icecap, the area now occupied by Lake Ellsworth was part of a marine basin. Researchers hope that a sediment core will reveal layers of marine sediments which can be dated according to the microfossils which they contain.
By cross-referring the date of these sediments – and by extension, the date at which the area was not glaciated – with evidence from elsewhere, it may be possible to identify not just the time but also the global temperature at which there was no ice. Such information could provide vital information about the potential temperature threshold for the collapse (melting) of the West Antarctic ice shelf and consequent implications for sea level rise.
Understanding the mechanisms of subglacial lakes, therefore, does more than just augment our knowledge of the lakes themselves, and any life they may contain. Details about subglacial bodies of water also provides glimpses of past climates, and by helping scientists understand the dynamics of ice sheets, which are potential drivers of climate change, this information augments studies and predictions of future global temperatures and sea levels.
Antarctica’s Gamburtsev Province Project (AGAP) Subglacial lakes. Accessed January 24, 2012
Kwok, R. et al. Ice Motion over Lake Vostok. (1999). California Institute of Technology/Bristol University.
Subglacial Lake Ellsworth, Antarctica. Subglacial Lake Ellsworth, Antarctica’s Hidden World. Accessed January 24, 2012.