From the vantage point of a helicopter hovering over Greenland, the challenge lies in grasping the sheer scale of the landscape. Initially mistaking icebergs for mere shards of ice and skimming over fjords that reveal their true enormity only when viewed from above, the mind struggles to comprehend the vastness of this icy wilderness. Crevasses, those telltale cracks in the glacier’s surface, further exemplify the bewildering contrasts of scale that characterize the region. From minuscule millimeter-wide rifts inland to gaping chasms hundreds of meters wide where the ice meets the ocean, these crevasses serve as markers of the ice sheet’s flow towards the sea.

Recent research has shed light on the changing nature of these crevasses, with significant increases in volume observed across fast-flowing sectors of Greenland’s ice sheet. Notably, the southeast region has experienced a notable surge in crevasse volume, signaling the impact of ocean-induced acceleration and retreat. However, a key outlier, the Sermeq Kujalleq glacier, has played a pivotal role in offsetting the overall increase in crevassing. This glacier, renowned as the fastest-flowing on Earth, temporarily slowed and thickened in response to environmental shifts, leading to a reduction in surface crevasses.

As these cracks grow and deepen, they contribute to the acceleration of ice loss from the ice sheet. Surface meltwater funneled into these crevasses can warm the ice or lubricate its base, hastening its flow into the ocean. Moreover, at the glacier’s terminus, crevasses serve as precursors to the calving of icebergs, further adding to the ice sheet’s output into the sea. The complex interplay between crevasses, ice flow, and sea-level rise underscores the urgency of understanding these processes as we strive to mitigate the impacts of climate change on our planet’s delicate cryosphere.