Researchers from Dartmouth University have unveiled fascinating new insights into the mechanisms driving the melting of glaciers beneath the surface of the ocean. This research is particularly focused on two significant glaciers located in the remote regions of West Antarctica: the Thwaites Glacier and the Pine Island Glacier. Collectively, these ice masses are responsible for over a third of the total ice loss from Antarctica. Thwaites Glacier, which is comparable in size to the state of Florida, has earned the ominous nickname of the "doomsday glacier" due to its potential to contribute significantly to rising sea levels.
Despite the urgency surrounding this issue, the precise processes through which these glaciers are melting remain shrouded in mystery. To address this gap in understanding, oceanographer and Dartmouth professor Yoshihiro Nakayama embarked on a mission to shed light on the situation. He developed a state-of-the-art, high-resolution model of the area, providing an incredibly detailed view of both the glaciers and the ocean at a resolution of just 200 meters. This innovative approach allows researchers to observe melting events as they occur on a much smaller scale, akin to analyzing daily weather patterns instead of looking at broader seasonal or annual trends.
Typically, oceanographers study these processes over time spans of months or even years, as the changes tend to be gradual. However, Nakayama's research revealed that by zooming in on shorter time frames, such as several days, it became evident that certain mechanisms were accelerating the melting process.
His findings suggest that underwater "storms"—specifically small eddies that form in the open ocean—could play a crucial role in this melting phenomenon. In a recent study published in the journal Nature Geoscience, Nakayama, alongside two other scientists, detailed how these eddies move toward the glaciers, penetrate the cavities beneath their ice shelves, and melt the ice from below.
Using the advanced modeling techniques, Nakayama and his team discovered that the rate of ice melt tends to spike temporarily before returning to average levels. During these peak periods, they observed the formation of eddies resembling underwater storms, which interact with the ice shelf similarly to how atmospheric storms impact land, causing damage along coastlines. "Just as storms affect the continent, these small ocean eddies can collide with the Antarctic ice and contribute to its melting," Nakayama explained.
The researchers identified a concerning feedback loop within their study: increased melting leads to more frequent ocean storms, which in turn accelerates further melting. Given the ongoing warming of our planet, this cycle could intensify, leading to even greater ice loss in the future.
Nakayama remains optimistic that his team’s work will enhance the scientific community's understanding of the physics underlying ice melt in Western Antarctica, paving the way for improved predictions regarding future melting scenarios. They argue that the daily melting events caused by these underwater "storms" should be integrated into climate models to provide more accurate projections of sea-level rise.
Observing the melting processes of Thwaites and Pine Island glaciers is inherently challenging due to their remote locations on Earth. However, the researchers emphasize the critical need for developing enhanced observational technologies to capture these underwater phenomena and their contributions to the melting of the ice.
"The implications of these underwater storms seem substantial based on our modeling results," Nakayama stated. "However, we must validate these findings through direct observations and apply this knowledge to other areas within Antarctica."
