Researchers have uncovered a surprising phenomenon in Antarctica: the massive Ross Ice Shelf, roughly the size of France, lurches forward several centimetres once or twice a day. This movement is triggered by the Whillans Ice Stream, a fast-flowing river of ice that occasionally gets stuck and then surges ahead.
The discovery highlights a previously unknown aspect of ice shelf dynamics and raises questions about the long-term stability of the Ross Ice Shelf in the face of climate change.
The research has been published in Geophysical Research Letters.
Sudden Shifts, Not Gradual Flow
Unlike most glaciers that creep at a glacial pace, the Whillans Ice Stream exhibits a stop-and-go motion. A lack of water lubrication beneath the stream may be causing it to intermittently stick, then release built-up pressure in sudden bursts.These jolts, similar to tremors along earthquake faults, push against the Ross Ice Shelf.
Icequakes and Fractures: A Potential Threat
While the daily jumps aren't directly linked to human-caused warming, they could contribute to the weakening of 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 monitoring the situation closely
The research team emphasises that icequakes and fractures are natural occurrences on ice shelves. However, they will be closely monitoring the Ross Ice Shelf for signs of disintegration, similar to what has happened to smaller ice shelves in the past.
This new study highlights the complex and dynamic nature of Antarctic ice shelves and the need for continued research to understand their future under a changing climate.
