Undersea ‘storms’ are melting the ‘doomsday’ glacier’s ice shelf

Recent studies have revealed a concerning phenomenon in Antarctica where underwater “storms” are causing accelerated melting of the ice shelf protecting the Thwaites glacier, often referred to as the “doomsday” glacier. These storm-like vortices, known as submesoscale features, can be up to 10 kilometres wide and are triggered when waters of varying density or temperature collide in the open ocean, similar to how hurricanes form in the atmosphere.

Researchers, led by Mattia Poinelli from the University of California, Irvine, have conducted modeling studies showing that these submesoscale features contribute significantly to the overall melt of the Thwaites and Pine Island ice shelves. These ice shelves play a crucial role in slowing down the glaciers’ movement towards the sea and protecting them from wave erosion. The Thwaites glacier alone loses 50 billion tonnes of ice annually and could potentially raise sea levels by 65 centimeters if it were to collapse.

One of the key mechanisms behind this accelerated melting is the interaction between colder, fresher surface water and warmer, saltier deep water in the Antarctic region. When a storm-like vortex becomes trapped beneath an ice shelf, it displaces the surface water, allowing warm deep water to rise and melt the ice from below. This process sets off a feedback loop, leading to intensified melting.

Further research led by Cathrine Hancock at Florida State University has shown that eddies, another type of swirling underwater feature, also contribute significantly to ice melt under ice tongues in Antarctica. The combined impact of these submesoscale storms and eddies underscores the need for a better understanding of how various scales of swirling water bodies are affecting ice melt and sea level rise.

As the planet continues to warm, it is expected that these underwater storms will become more intense, potentially leading to higher sea level rise than currently predicted. Tiago Dotto from the UK National Oceanography Centre emphasizes the importance of increased observations from under ice shelves to better comprehend the impact of these small-scale phenomena in Antarctica.

The findings from these studies highlight the urgent need to address the complex interactions between ocean dynamics and ice melt in Antarctica, especially in the context of climate change. By gaining a more comprehensive understanding of how underwater storms are contributing to ice shelf destabilization, we can improve our projections of future sea level rise and take necessary steps to mitigate its impact.