Researchers have discovered a hidden world of subglacial water beneath the Antarctic Ice Sheet that significantly impacts sea level rise. This water world, made up of streams and lakes, plays a crucial role in the movement of glaciers and the flow of ice towards the ocean. The pressure exerted by this subglacial water counters the weight of the overlying glacier, lubricating the ground and enhancing the glacier’s movement. While scientists already understood this process, they were unsure of the extent to which it affects glacier flow and sea-level rise.
The movement of the Antarctic Ice Sheet is not static, as it deforms under its own weight and experiences basal sliding, where the ice slides along the ground like a sled on snow. Basal sliding accounts for the rapid movement of glaciers flowing into the ocean and is essential for estimating future sea-level rise. However, many current ice sheet models do not consider the effects of subglacial water, potentially underestimating its impact on sea level rise.
In a recent study, researchers simulated the flow of the Antarctic Ice Sheet over subglacial channels and lakes to understand the effects of subglacial water pressure. By testing different scenarios, such as assuming unhindered water flow into the ocean or factoring in the topography beneath the ice sheet, they aimed to create a more accurate picture of how subglacial water impacts glacier flow and sea level rise. They found that increasing the slipperiness near the grounding line, where the ice meets the ocean, led to significant increases in sea level rise projections by 2300.
One simulation with a slippery grounding line generated an additional 2.2 meters of sea level rise, compared to standard models that ignore the effects of subglacial water. This result represents only a small fraction of the potential sea level rise that could occur if the entire Antarctic Ice Sheet melted. Further research into the distribution and behavior of subglacial water beneath the Antarctic Ice Sheet is essential to refine predictions of future sea level rise and better understand the impact of this hidden water world.
Understanding the behavior of subglacial water beneath Antarctica is crucial for accurately predicting future sea level rise and assessing the impacts of climate change. The findings of this study highlight the need to incorporate subglacial water dynamics into ice sheet models to improve projections of sea level rise and inform policymakers about the potential consequences of melting ice in Antarctica.
