A new study has brought to light the intricate and ever-changing nature of Antarctic ice shelves. Researchers have made a surprising discovery in Antarctica: the massive Ross Ice Shelf, comparable in size to France, moves forward several centimetres once or twice a day. This movement is caused by the Whillans Ice Stream, a fast-moving river of ice that occasionally gets stuck and then surges ahead. This finding reveals a previously unknown aspect of ice shelf dynamics and raises concerns about the long-term stability of the Ross Ice Shelf in the face of climate change.
Published in Geophysical Research Letters, the research highlights how the Whillans Ice Stream exhibits a stop-and-go motion, unlike most glaciers that move at a slow pace. The lack of water lubrication beneath the stream may be causing it to intermittently stick and then release built-up pressure in sudden bursts. These sudden shifts, resembling tremors along earthquake faults, exert pressure on the Ross Ice Shelf.
While the daily movements are not directly linked to human-induced warming, they could contribute to weakening the Ross Ice Shelf. Ice shelves act as barriers, slowing the flow of glaciers and ice streams into the ocean. If the Ross Ice Shelf weakens and breaks apart, it could accelerate ice melt rates and sea level rise. Scientists are closely monitoring the situation.
The research team points out that icequakes and fractures are natural events on ice shelves. However, they will be vigilant in observing the Ross Ice Shelf for signs of disintegration, similar to past occurrences with smaller ice shelves. The study underscores the complex and dynamic nature of Antarctic ice shelves and emphasizes the need for ongoing research to comprehend their future under a changing climate.
