Greenland’s Ice Sheet: Softer Within, Faster to Melt

Two recent scientific studies have significantly reshaped our understanding of the Greenland Ice Sheet, the world’s second-largest mass of ice after Antarctica. The findings suggest that the ice sheet is undergoing internal and surface transformations at a pace and in ways that scientists did not fully anticipate.

A study published in The Cryosphere by researchers from the University of Bergen reveals that plume-like structures detected deep within the ice are likely the result of thermal convection — the same physical process that drives circulation in Earth’s mantle. Geothermal heat rising from the crust gradually warms the base of the ice sheet, making it soft enough to rise in slow, column-like motions while still remaining solid.

This discovery challenges conventional assumptions about how ice sheets behave. Because ice is vastly softer than the Earth’s mantle, the physical conditions required for convection are more easily met than previously thought. The phenomenon appears most prominently in northern Greenland, where ice thickness exceeds 2,200 meters and snowfall rates are low enough to allow upward motion to develop. Importantly, the findings indicate that deep ice in this region may be up to ten times softer than earlier estimates — a factor that could significantly alter projections of future sea level rise.

A separate study, published in Nature Communications and led by researchers from the University of Barcelona, documents a sharp acceleration in extreme melting events across Greenland between 1950 and 2023. Since 1990, the area affected by extreme melt events has expanded by approximately 2.8 million square kilometers per decade. Meanwhile, meltwater production has increased more than sixfold, rising from 12.7 gigatons per decade to 82.4 gigatons per decade.

Seven of the ten most severe melting episodes on record have occurred since 2000, including unprecedented events in August 2012, July 2019, and July 2021. Northern Greenland has emerged as a primary hotspot. Under high-emission scenarios, extreme meltwater anomalies could rise by as much as 372 percent by 2100.

Together, these studies suggest that both the internal physics and surface behavior of the Greenland Ice Sheet are evolving more rapidly than established models had assumed. The implications extend beyond environmental concerns, affecting global sea levels, ocean circulation systems, and even geopolitical dynamics in the Arctic. For coastal planners and policymakers worldwide, the stakes have never been higher.