Scientists find trapped heat beneath Greenland — impacting ice sheet motion and future sea level rise

Understanding what happens beneath Greenland helps explain how its vast ice sheet moves, melts, and reshapes the planet. A new study offers a clearer picture of the hidden heat deep below the island and nearby northeastern Canada, revealing how Earth’s interior still reflects ancient tectonic forces.

Researchers led by the University of Ottawa created highly detailed three-dimensional models of temperature in the Earth’s lithosphere and upper mantle beneath Greenland. These models help explain how the region’s geologic past continues to affect ice behavior, land motion, and future sea level change.

The study combined satellite observations with land-based measurements, including seismic wave speeds, gravity data, and surface heat flow. By merging these datasets, the team reconstructed how temperature varies beneath Greenland, both horizontally and with depth.

This effort required large-scale computing. Researchers ran hundreds of thousands of simulations using high-performance systems, including resources from the Digital Research Alliance of Canada. The result was a probabilistic model that captures uncertainty while still matching real-world observations.

The work was led by scientists at the University of Ottawa, with collaborators from the University of Twente in the Netherlands and the Geological Survey of Denmark and Greenland. Together, they produced one of the most detailed regional thermal maps of the area to date.

Greenland’s journey over the Iceland hotspot has long been recognized, but the exact path remains debated. The new temperature models reveal strong lateral differences that align with a west-to-east track across central Greenland.

“Our new regional temperature models reveal significant lateral variations in the Earth's thermal structure beneath Greenland, which provide important information on the island’s passage over the Iceland hotspot,” said Parviz Ajourlou, a PhD graduate at the University of Ottawa and the study’s first author.

These temperature contrasts reflect ancient mantle heat that altered the strength and behavior of rocks deep below the surface. Over millions of years, that heat shaped how the region stretched, cooled, and stabilized.

By connecting temperature patterns to tectonic history, the study offers independent support for hotspot reconstructions. It also helps explain why some areas respond differently to the weight of ice than others.

Heat inside the Earth controls how stiff or soft the underlying mantle behaves. Warmer regions deform more easily, while cooler areas resist change. This matters when massive ice sheets grow or shrink.

Using their temperature model, the researchers estimated how mantle viscosity varies beneath Greenland. They found differences reaching three orders of magnitude within the upper mantle. Such contrasts strongly influence how fast the land rebounds when ice melts.

Glenn Milne, Chair and Full Professor in Earth and Environmental Sciences at the University of Ottawa, emphasized the link to modern observations. “Temperature variations directly influence the interaction between the ice sheet and the bedrock, which must be quantified to interpret observations of land motion and gravity changes.”

Those observations, gathered from satellites and ground stations, reveal how Greenland responds to recent warming. Accurate models of Earth’s interior help separate ice-driven effects from deeper geologic influences.

The team generated an ensemble of possible three-dimensional viscosity models and tested them against records of ancient sea levels and modern vertical land motion. The models matched both datasets well.

This agreement supports the reliability of the new temperature estimates. It also challenges the idea that large, short-term deformation effects are required to explain current observations.

By refining how Earth structure is represented, scientists can improve reconstructions of Greenland’s ice history. The models also strengthen simulations of how ice sheets and sea levels may evolve under future climate scenarios.

“This work is a good illustration of how our knowledge of the solid Earth enhances our ability to understand the climate system,” Ajourlou said. “By improving how we model ice-earth interactions, we can better forecast future sea level rise and plan accordingly.”

The findings help improve predictions of sea level rise by clarifying how Earth’s interior responds to melting ice. Better viscosity models reduce uncertainty in forecasts used by coastal planners and climate scientists.

The work also supports more accurate interpretations of satellite gravity and land motion data. Over time, these advances can inform risk assessments for coastal communities and guide future climate adaptation strategies.

Research findings are available online in the journal PNAS.

Like these kind of feel good stories? Get The Brighter Side of News' newsletter.