Scientists Detect Giant Swirling Plumes Deep Within Greenland’s Ice Sheet

Researchers have discovered a new phenomenon deep within Greenland’s ice sheet: vast, swirling plumes that challenge existing theories about ice movement. Using advanced mathematical models similar to those used for studying continental drift, scientists from the University of Bergen (UiB) and international collaborators have proposed that these structures form through thermal convection—a process typically associated with Earth’s molten mantle, not ice. The study, accepted for publication in The Cryosphere, a leading glaciology journal, reveals that temperature differences within the ice drive slow, churning motions that could reshape predictions about ice sheet behavior in a warming climate. These plumes, first detected over a decade ago via radar imaging in northern Greenland, distort internal ice layers into broad, upward-bulging shapes hundreds of meters wide, which do not conform to typical ice flow or bedrock patterns. The discovery was made possible through a combination of seismic data, radar imaging, and satellite observations, which revealed the plumes’ existence beneath kilometers of ice. Researchers from UiB, NASA Goddard Space Flight Center, the University of Oxford, and ETH Zurich collaborated to analyze these structures, integrating data from multiple sources to confirm their origin.

The plumes, described as resembling ‘rising currents in a boiling pot’, span vast distances and exhibit patterns that defy traditional models of ice sheet behavior. Dr. Andreas Born, a professor at UiB’s Bjerknes Centre for Climate Research, referred to the phenomenon as a ‘freak of nature’, emphasizing that ice, though solid, can exhibit fluid-like properties under extreme conditions. The research team’s models suggest that the ice’s softness—about ten times softer than previously estimated—allows for these convective movements. This finding has significant implications for understanding how ice sheets respond to climate change, as softer ice may flow differently than assumed, altering predictions of sea-level rise. The study’s acceptance as a ‘highlight paper’ in The Cryosphere reflects its potential to advance the field by bridging gaps in ice sheet physics. The research also builds on decades of Arctic climate studies conducted by the Bjerknes Centre, which has been at the forefront of investigating ice dynamics in the region.

“‘It’s like an exciting freak of nature,’”

Thermal convection in ice operates on principles similar to those in Earth’s mantle, but with unique adaptations. The process relies on temperature differences between deeper, warmer layers and shallower, colder layers. As heat accumulates in the lower ice, it creates buoyancy-driven currents that rise, while colder, denser ice sinks, forming the swirling plumes. This contrasts with the rigid, static perception of ice as an unyielding material. Dr. Robert Law, a glaciologist and lead author of the study, explained that ice’s extreme softness—up to a million times softer than Earth’s mantle—enables such motion. ‘It’s like an exciting freak of nature,’ he said, noting that the physics align with the observed phenomena despite initial skepticism. The study’s models, which simulate the ice’s thermal properties, revealed that these plumes are not random but follow predictable patterns. The researchers compared the ice’s behavior to ‘a slow-moving river of frozen water’, where heat transfer drives the movement. This challenges the long-held assumption that ice sheets are passive, static entities. Instead, the findings suggest that ice can exhibit dynamic, self-sustaining processes that influence its structure and stability. Such insights could refine models of ice flow and improve forecasts of how ice sheets might respond to future climate scenarios.

The study’s simulations, conducted using advanced geodynamics software like ASPECT, replicated the plumes when basal ice was warmer and about ten times softer than previously assumed. This finding aligns with observations from NASA’s satellite data, which revealed variations in ice thickness and thermal gradients across Greenland. The researchers also noted that the plumes’ formation is influenced by geothermal heat and past ice sheet conditions, which have shaped the ice’s internal structure over thousands of years. The discovery underscores the complexity of ice dynamics, as thermal convection in ice is not a new phenomenon but one that has been overlooked due to the assumption that ice is a rigid material. By incorporating these findings into climate models, scientists can better account for the ice sheet’s internal movement, which may have been previously underestimated. This has significant implications for understanding how ice sheets interact with a warming climate, as internal processes like thermal convection could influence both ice flow and melt rates.

The discovery of thermal convection in Greenland’s ice sheet has profound implications for climate science. The study suggests that deep ice in northern Greenland may be ten times softer than previously believed, which could alter how scientists model ice flow and mass balance. However, the researchers caution that softer ice does not automatically translate to faster melting. ‘Improving our understanding of ice physics is a major way to be more certain about the future,’ said Law. ‘But on its own, softer ice does not necessarily mean the ice will melt faster or that sea level rise will be higher.’ This distinction is critical. While the study provides a more accurate picture of ice behavior, it does not predict catastrophic changes in Greenland or global sea levels. Instead, it underscores the complexity of ice sheet dynamics. The findings could help refine models that project future sea-level rise by incorporating the role of internal ice movement. However, further research is needed to isolate the impact of ice softness from other factors, such as surface melting and oceanic interactions. The study’s acceptance as a ‘highlight paper’ in The Cryosphere reflects its potential to advance the field by bridging gaps in ice sheet physics.

The research also highlights the importance of accurate ice flow modeling in predicting future sea-level rise. Current models often assume ice sheets are rigid and static, but the discovery of thermal convection suggests that internal movement plays a significant role in ice dynamics. By integrating these findings, scientists can improve the precision of projections, which is essential for coastal planning and climate policy. The study’s emphasis on internal ice movement aligns with broader efforts to understand how ice sheets respond to climate change. For example, recent research from the University of Oxford has shown that ice sheet stability is influenced by both surface and subsurface processes, including thermal convection. These findings reinforce the idea that ice sheets are dynamic systems influenced by a complex interplay of factors, from temperature gradients to geothermal heat. As global temperatures continue to rise, understanding these internal processes will be critical for refining climate models and predicting the long-term impacts of ice sheet behavior on global sea levels.

The research was a multinational effort involving institutions such as NASA Goddard Space Flight Center, the University of Oxford, and ETH Zurich. Each partner contributed specialized expertise: NASA provided satellite data on ice thickness, Oxford’s geophysicists modeled thermal gradients, and ETH Zurich’s engineers developed the computational tools to simulate convection patterns. This collaboration exemplifies the growing trend of interdisciplinary and international cooperation in climate science, where complex problems require diverse perspectives. The Bjerknes Centre for Climate Research, based at UiB, has been at the forefront of Arctic climate studies for decades, and this work builds on its legacy. The involvement of NASA underscores the role of space-based observations in monitoring Earth’s cryosphere, while Oxford and ETH Zurich’s contributions reflect the global nature of climate research. Such collaborations are essential for tackling the multifaceted challenges of climate change.

“‘Improving our understanding of ice physics is a major way to be more certain about the future,’”

The study’s significance extends beyond its scientific findings. By integrating data from multiple sources, the research highlights the importance of cross-institutional partnerships in addressing global challenges. The Bjerknes Centre’s long-standing focus on Arctic climate research, combined with NASA’s satellite capabilities, Oxford’s geophysical modeling, and ETH Zurich’s computational expertise, created a robust framework for analyzing the ice sheet’s behavior. This collaborative approach is increasingly common in climate science, where the scale and complexity of the issues demand a multidisciplinary effort. The success of this study demonstrates how international cooperation can lead to breakthroughs in understanding Earth’s systems, even in the most extreme environments. As climate change continues to pose significant challenges, the ability to pool resources, expertise, and data across borders will be crucial for developing effective solutions.

Greenland’s ice sheet, the second-largest on Earth, holds enough ice to raise global sea levels by 7 meters if fully melted. The study’s findings add to a growing body of research on how this ice sheet interacts with a warming climate. While the discovery of thermal convection does not predict immediate collapse, it reinforces the idea that ice sheets are dynamic systems influenced by both internal and external factors. The ice sheet’s age—over one thousand years—and its unique characteristics, such as permanent settlements at its margins, make it a critical focus for climate scientists. The presence of human populations at the ice sheet’s edge adds a layer of complexity, as these communities are directly affected by changes in ice dynamics and sea-level rise.

The research also aligns with broader efforts to understand the role of ice sheets in global climate systems. As temperatures rise, the interplay between ice dynamics, ocean currents, and atmospheric conditions becomes increasingly complex. The study’s emphasis on internal ice movement highlights the need for more comprehensive models that account for such processes. By improving our understanding of Greenland’s ice, scientists can better predict regional and global impacts of climate change, from coastal flooding to ecosystem shifts. The discovery of these plumes is a reminder that even in the most extreme environments, nature continues to surprise us with its complexity. Furthermore, the findings underscore the importance of continued research into ice sheet behavior, as the implications of these discoveries extend far beyond Greenland, influencing global climate policy and coastal adaptation strategies.