Ice-clad Greenland is shrinking

Greenland is drifting to the northwest as the ice melts, it's shrinking and rising also

Alarming signs? Ice-clad Greenland is shrinking and slowly drifting northwest. New research from DTU Space shows that Greenland is undergoing a massive shift because of climate change, it’s quite literally accelerating the melting of the Danish territory. A study recently published by DTU in the Journal of Geophysical Research: Solid Earth outlined that Greenland is twisting, compressing and stretching while drifting northwest by 2 cm's a year over the past two decades. Greenland is on the move, not just its ice, but the island itself. The bedrock is being twisted, compressed and stretched as Earth responds to both ancient and modern ice loss. At the same time, different regions simultaneously expand and contract. The result is a landscape that’s subtly reshaping beneath our feet.

Ice sheets are melting, causing the tectonic plates to shift and setting Greenland adrift. According to researchers, Greenland is expanding and contracting at the same time, much like the rest of the universe, albeit horizontally. It’s being stretched out, and other parts are being pulled together. Ice is heavy. Pile miles of it onto bedrock and the crust sags; remove that weight and the crust rebounds. Greenland is experiencing both effects at once. Some of the pressure is easing because modern warming has stripped vast quantities of ice from the ice sheet in recent years. But the bedrock is also still rebounding from a far older shift. That shift began at the end of the last Ice Age, when colossal ice masses started melting away about 20,000 years ago. Those overlapping forces, glacial isostatic adjustment from the deep past and rapid melt from the present, are not only lifting the bedrock. They’re also shearing the island laterally, producing a slow but measurable north-westward drift and complex patterns of horizontal strain. In some places, Greenland is being pulled apart; in others, it’s being squeezed.

Though ice has been melting, the problem is the rate at which Greenland is disappearing and changing. Climate change is the culprit, according to researchers. Greenland has been losing more ice than it can reproduce for 28 years. Should we be worried? Maybe. At least, the new research provides evidence as to what happens when climate change hits the Arctic at an accelerated rate. To capture these movements with unprecedented clarity, DTU Space scientists used a network of 58 permanent GNSS (GPS) stations distributed around Greenland. Over 20 years, those instruments logged the island’s exact position. They also measured the vertical uplift of the crust. Then they tracked horizontal changes which reveal where the land is stretching or contracting. “There have not previously been such precise measurements of how Greenland is shifting,” said lead author Danjal Longfors Berg, a postdoctoral researcher at DTU Space. The prevailing assumption, he noted, was that recent melt would mainly stretch the island outward. “But to our surprise, we also found large areas where Greenland is being ‘pulled together,’ or ‘shrinking,’ due to the movements.”

DTU Space postdoc researcher Danjal Longfors Berg said that Greenland ice has notably “melted in recent decades, which has pushed Greenland outward and caused uplift, so the area has actually become larger during this period. At the same time,” he continued, “we see movement in the opposite direction, where Greenland is rising and contracting due to prehistoric changes in the ice masses related to the last Ice Age and its end.” The team paired those modern observations with a geophysical model that spans roughly 26,000 years, linking the end of the last glacial maximum to the present day. That long lens helps separate the signature of ancient ice loss from the newer signal of accelerated melting in a warming climate. Strip away ice and the crust springs back. That vertical rebound is evident across Greenland, where many GNSS stations show steady uplift. But the new study digs into what that uplift means for surface area. It’s not straightforward. The crust flexing like a trampoline relieved of weight; the rim shifts outward a touch as the centre rises.

The team created a model that tracked these movements over 26,000 years. That, along with data from 58 GNSS stations around Greenland, allowed them to calculate the island’s movements over the last two decades to unprecedented precision. They measured its overall position, the bedrock’s elevation changes, and how Greenland appears to be expanding and contracting. At the same time, the lingering, long-period response to post-Ice Age changes is working in the opposite direction: a slow contraction paired with uplift as the mantle continues to flow and rebalance. The net effect right now, the researchers found, is that Greenland is “overall becoming slightly smaller.” However, that balance could flip as modern melt accelerates. In other words, Greenland’s footprint is not fixed. It subtly breathes in and out, expanding and contracting in different places, as ancient and modern forces compete. Horizontal land motion observed on Greenland by the 58 GNET stations used in this study, processed in the IGS14 reference frame. Their location is shown by the colour circles together with their labels. The boundaries of Greenland’s ice melt drainage basins are shown in green with numbers. The Greenland Ice Sheet (GrIS) is represented in white and peripheral glaciers in Greenland (GrPG) and Arctic Canada (CanPG) are highlighted in black and purple, respectively. 

Researchers not only found an unexpected reaction from the landmass, but they also brought to light how disconcerting the phenomenon is. Beyond the vertical motion, the island is also sliding laterally about two cm's per year toward the northwest. That drift reflects how the mantle’s viscous flow and the geometry of ice loss redistribute stress beneath the crust. As mass shifts, the solid Earth responds like a very slow, very thick fluid. The direction and speed of Greenland’s slide are a fingerprint of how that deep, creeping flow is playing out under the Arctic. Understanding these motions isn’t just a matter for geophysicists. Land movement complicates surveying, navigation and geodetic reference frames. “There have not previously been such precise measurements of how Greenland is shifting. The assumption has been that Greenland is primarily being stretched due to the dynamics triggered by the ice melting in recent years. But to our surprise, we also found large areas where Greenland is being ‘pulled together,’ or ‘shrinking,’ due to the movements,” Danjal Longfors Berg said. If the “fixed” benchmarks in Greenland are moving fractions of an inch per year, coordinates tied to those benchmarks slowly drift unless continuously updated. For coastal communities and scientists tracking sea-level change, that matters, too: tide-gauge records and satellite altimetry must account for a rising seabed as well as a rising sea.

Greenland Ice Sheet is one of the most significant sources of freshwater for the planet. The good news is, last year, in 2024, it suffered the least loss since 2013. However, it has been losing more ice than it can make for 28 years. “It’s important to understand the movements of landmasses,” Berg said. “They are of course interesting for geoscience. But they are also crucial for surveying and navigation, since even the fixed reference points in Greenland are slowly shifting.” Greenland is warming faster than the global average, and its ice sheet is one of the planet’s largest contributors to sea-level rise. This makes the island a natural laboratory for watching how the solid Earth reacts to rapid climate-driven mass loss. The DTU Space model, spanning from the late Ice Age to the satellite era, offers a framework to predict how today’s melt will translate into tomorrow’s uplift, stretching and drift. How that stands to impact the world at large remains to be seen, though it has caused concern. Researchers instead are concentrating on what this accelerated shift of landmass has to teach geoscience about how it can move. But studying landmasses has a significance beyond that.

The study’s headline can be summed up simply: Greenland is not static. It’s flexing upward, sliding northwest, and deforming horizontally in a pattern shaped by both ancient deglaciation and modern melt. The opposing forces make Greenland slightly smaller overall, even as some regions stretch larger,  a balance that keeps shifting. If ice loss continues to accelerate, the map of Greenland may, in tiny but measurable ways, change with it. In a world that often thinks of continents as immovable, this is a reminder that the ground beneath us is always in motion. “They are also crucial for surveying and navigation, since even the fixed reference points in Greenland are slowly shifting,” Berg said. But what’s going to happen to the world? Anything, unpredictable at this point of time.