New study discovers a 460-km river under the Antarctica ice sheet
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The discovery of a 460-km river under the Antarctica ice sheet could be the missing link to climate models.
From a series of airborne radar surveys and modelling, a team of researchers led by Dr. Christine Dow, professor in the school of Geography and Environmental Management and a Waterloo Climate Institute member, discovered the river. Their findings show the base of the ice sheet has more active water flow than previously thought, which could make it more susceptible to changes in climate.
From satellite measurements we know which regions of Antarctica are losing ice, and how much, but we don’t necessarily know why. This discovery could be a missing link in our models. We could be hugely underestimating how quickly the system will melt by not accounting for the influence of these river systems.
The Antarctic Weddell Sea region, where this study is based, holds enough ice to raise the sea level globally by 4.3 meters and the newly discovered river will play a key role in that sea level rise. Dow and her colleagues showed that the large volume of freshwater pumped from the river into the ocean causes enhanced melt at the sensitive region where ice flows into the ocean and begins to float. In the future, if warm air temperatures cause enough surface melt to reach the base of the ice sheet, it could tip Antarctica to a Greenland-like state, with much higher volumes of freshwater flowing into the ocean. More freshwater in the river will likely lead to more melt, shrinking of the ice sheet, and an increase in ice flow rate. Ultimately, these controls on the flow of the ice into the ocean will determine much of the future sea level rise. As Dow says, “only by knowing why ice is being lost can we make models and predictions of how the ice will react in the future under further global heating, and how much this could raise global sea levels.”
Modelled subglacial hydrology.
The study Antarctic basal environment shaped by high-pressure flow through a subglacial river system published in the journal of Nature Geoscience, illustrates that large under-ice rivers need to be accounted for in climate change modelling to predict surface melt and ice loss. In the future, Dow and her team will be looking to gather more data and apply their models to other regions to provide a better understanding of how a changing Antarctica could alter the planet.
Learn more about Dow's work and discover this year's collection of Waterloo Climate Institute member publications.
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