Northwest Greenland contains a buried landscape that shows how the ice sheet responds when regional temperatures rise a few degrees above modern levels. Sediments recovered from beneath Prudhoe Dome, an inland ice structure covering roughly two thousand five hundred square kilometers, reveal that the site was ice free during the Holocene. The grains in the upper layers of the subglacial material carry luminescence signals indicating exposure to direct sunlight about seven thousand years ago. Such exposure is only possible when the ice above them is gone. The ice column now present consists entirely of Holocene ice, which means the earlier body of ice at this location disappeared completely and did not return until after the climate cooled.
Early Holocene summer temperatures in northwest Greenland reached values three to seven degrees Celsius higher than today. Chironomid records from nearby lakes show strong July warming. Ice core records from Ellesmere Island show annual temperatures three to six degrees above present. These levels coincide with the interval when Prudhoe Dome was absent. Modern climate projections for northwest Greenland fall inside the same range by the end of this century. The temperatures that removed the dome in the past are similar to what is expected again.
Prudhoe Dome sits inland on a structural high point within the northwest sector of the Greenland Ice Sheet. It functions as a reservoir of elevated mass that influences how ice flows toward Nares Strait and northern Baffin Bay. When the dome melted during the Holocene, the summit and its surrounding region would have lost elevation. Lower elevation accelerates surface melt because the ice occupies warmer layers of the atmosphere. Meltwater runs across a surface that becomes darker and absorbs more energy. A lower landscape also enhances the exposure of ice to warm seasonal conditions, extending melt seasons and increasing the volume of water reaching the coastline.
In a modern collapse scenario, changes in this region would influence downstream systems. Outlet glaciers such as Petermann, Ryder and Steensby draw ice from this interior sector. Their flow depends in part on the elevation and thickness of the ice feeding them. A reduction in structural support upstream allows mass to move more quickly toward the coast. Once inland ice accelerates, thinning follows. Thinner ice near the grounding line allows more interaction with warm ocean water, which drives additional retreat. The feedback between inland loss and coastal discharge becomes stronger in a warming climate.
During the Holocene collapse of Prudhoe Dome, the land at the summit was exposed and subject to permafrost processes. Sediments from the recovered core show signs of mixing that occur when surface soils thaw and refreeze each year. Seasonal thaw at this elevation indicates that no ice remained at the site. To reproduce those conditions today, more than five hundred meters of ice would have to disappear. Reaching that state requires sustained summer warming similar to the early Holocene. Climate projections for northwest Greenland indicate a move toward those same temperatures in the coming decades.
The landscape beneath Prudhoe Dome is not unique. The North Ice Cap in the same region shrank or vanished for long periods during the Holocene. The Hans Tausen Ice Cap underwent large scale melt. Sediment cores from regional lakes show uninterrupted periods when glaciers were retracted far inland. During these intervals, coastal and inland sectors responded to moderate climate shifts by losing large amounts of ice. Some ice caps reformed only after temperatures cooled substantially. The present climate system is moving in the opposite direction.
If Prudhoe Dome melts again, the entire profile of the northwest interior changes. Its summit is a mass of elevated ice that currently slows the movement of inland flow toward Nares Strait. Without it, the gradient steepens. Ice adjusts to this new configuration by accelerating downslope. As elevation drops, the balance between accumulation and melt becomes unfavorable. Snowfall cannot compensate for the increased melt. The surface darkens due to exposed sediments and older ice layers. Meltwater drains through new channels. The structure that held the region at altitude no longer exists.
In this altered landscape, the inland area becomes a source of mass loss feeding increased discharge at the coast. Outlet glaciers with weakened grounding lines respond by retreating more quickly. Calving fronts destabilize as they interact with warmer water for longer periods. The inland thinning and coastal retreat reinforce each other. The region enters a state in which melt and discharge both intensify under the influence of elevated temperatures.
Global sea level responds to changes in Greenland’s interior. When inland flow strengthens and coastal glaciers lose mass, the contribution to sea level rise increases. The disappearance of Prudhoe Dome in the Holocene occurred during a natural climate cycle. Modern warming is driven by greenhouse gas emissions and is projected to continue increasing this century. The alignment between past temperature levels and future projections places Greenland in a position where inland retreat can occur under near term conditions.
Past reconstructions show that the early Holocene melt event at Prudhoe Dome unfolded during a period when the region experienced rapid summer warming. Modern observations show that the Arctic is warming four times faster than the global average. Sea ice decline increases regional heat absorption. Snow cover retreats earlier. Melt seasons begin sooner and end later. Atmospheric moisture levels have changed, affecting cloud cover and heat retention. These forcing mechanisms raise temperatures across the Greenland Ice Sheet and increase melt efficiency relative to Holocene rates.
The disappearance of Prudhoe Dome in the Holocene required a specific temperature threshold. The recovery required long term cooling. Modern warming is moving toward the same threshold without any indication of a reversal. Once the dome begins to thin significantly, the climate conditions necessary for reformation are absent. Any inland collapse becomes part of a large scale retreat pattern that aligns with rising global temperatures.
The structural role of Prudhoe Dome becomes more apparent when considering the spatial connections within the northwest interior. The dome sits on higher ground and governs flow into multiple drainage basins. These basins provide ice to some of the region’s most active outlet glaciers. An inland collapse not only destabilizes local conditions but alters the mass balance of the entire northwest quadrant. Elevation loss triggers a shift in regional flow patterns. This shift influences discharge velocity and the rate at which ice enters the ocean.
The Holocene collapse left behind a landscape that showed clear signs of exposure. The sediments at the summit recorded mixing through freeze thaw cycles. The absence of older ice layers in the ice core demonstrates that nothing from the previous glacial cycle survived. Modern ice at Prudhoe Dome is rebuilt entirely from the past seven thousand years. The thickness of the present dome does not indicate resistance to warming. It indicates the time available since the last collapse to rebuild under cooling conditions.
Greenland today does not exist in a cooling phase. Atmospheric greenhouse gas concentrations continue to rise. Arctic amplification accelerates temperature increases. Ocean heat is penetrating farther into polar regions. Conditions are forming that match, and in some respects exceed, those that eliminated Prudhoe Dome during the Holocene.
Surface melt on Prudhoe Dome now begins earlier in the year than it did decades ago. Regional temperature anomalies show a consistent upward trend. Snow accumulation has not increased enough to offset these changes. Meltwater routing across the dome has become more complex as temperatures warm. These observations support the idea that Prudhoe Dome is moving toward conditions documented in its own geological record.
When the dome collapses, the region behind it does not stabilize at a reduced configuration. It continues losing mass because the surrounding environment favors melt over accumulation. Snowfall that once preserved elevation becomes insufficient. The entire region enters a prolonged period of negative mass balance. Once this state is reached, the inland ice that once sat securely on high ground becomes a source of continuous meltwater entering downstream systems.
Global coastlines would absorb this signal. Sea levels have already risen due to thermal expansion and melt from glaciers and ice sheets. Additional mass loss from an inland collapse in northwest Greenland would raise sea levels further. The volumes at stake are large because Prudhoe Dome is not a marginal feature. It connects directly to regions that feed major outlet glaciers.
As warming continues, the distribution of stress within the ice sheet changes. Cracks propagate more easily across weakened ice. Meltwater reaches deeper layers. The transition from stable interior to thinning interior can occur rapidly once key thresholds are crossed. Prudhoe Dome’s past shows how quickly a major inland ice body can vanish when temperatures reach certain levels.
The modern climate is moving toward the same range that triggered that collapse. If those levels are reached and maintained, the present dome cannot remain intact. Once removed, the interior reconfigures. That reconfiguration transfers mass toward the coastline. The coastline responds with accelerated retreat. The combined effects increase global sea level and reduce Greenland’s ability to slow its own loss.
The geological evidence from beneath Prudhoe Dome documents a climate state in which northwest Greenland carried no ice at the summit despite its current massive structure. The temperatures associated with that state are expected again by the end of this century. When that point arrives, the landscape will follow patterns already preserved in the sediments. Inland regions will thin. Elevation will drop. Melt will intensify. Discharge will rise. The future course of the northwest interior will follow the path that once removed Prudhoe Dome from the landscape completely.
Source:
Based on the January 2026 Nature Geoscience study Deglaciation of the Prudhoe Dome in northwestern Greenland in response to Holocene warming (https://doi.org/10.1038/s41561-025-01889-9).
