As a glacier melts and retreats up the valley it formed in, it exposes deep, bowl-shaped hollows in the surrounding landscape that quickly fill with meltwater. These lakes are known as ice-marginal lakes (or IMLs) and they can grow as large as 117km2, which is roughly the same area occupied by the urban subdivision of Leeds in England.<\/p>\n
The recent study,\u00a0published last week in the journal Communications\u00a0Earth and Environment<\/a>, demonstrates IMLs aren\u2019t just the results of retreating glaciers, but rather active agents in their demise, destabilising them, triggering movement, and increasing thinning, all of which contribute to ice loss.<\/p>\n When a glacier flows into an IML, its front is partly lifted, exposing its underside to increased melting. This reduces the friction that typically slows the glacier\u2019s flow and increases the likelihood of large slabs breaking away via a process known as \u2018calving\u2019.<\/p>\n Using satellite data, the researchers found that the speed of glaciers ending in IMLs was three times faster at their fronts than those terminating on land. These alarming levels of acceleration weren\u2019t just confined to the glaciers\u2019 edges either; the researchers detected this effect up to 3.5km inland.<\/p>\n \u201cWhen glaciers flow faster, they deliver more ice to lower elevations, where it can melt, or to their fronts, where it can break away,\u201d said the study\u2019s lead author Connie Harpur. \u201cBy showing that lakes at the ice margin can substantially speed up glaciers, we identify an important process that needs to be included in predictions of future ice loss.\u201d<\/p>\n While this isn\u2019t the first time such an effect has been documented – earlier observations from the Himalayas have shown glaciers ending in IMLs can move twice as fast as their land-based counterparts – it is the first time it has been properly examined and measured in Greenland.<\/p>\n So far, ice dynamic models of the Greenland ice sheet have seldom taken into account the role IMLs play. The authors involved in this latest study argue such models urgently need to factor in IMLs if they\u2019re to accurately project the short and long term health of this important ice sheet.<\/p>\n \u201cIf we do not account for lake effects, we may underestimate how dynamically parts of the ice sheet respond to future warming, and in turn how much Greenland will contribute to future sea level rise,\u201d said co-author Mark Smith. \u201cUnderstanding ice-marginal lakes\u2019 influence on glacier flow is crucial for accurate projections.\u201d<\/p>\n As well as having disastrous implications for our own species, rising sea levels threaten other species too, particularly those living on the icy frontiers of the Arctic. The waters surrounding Greenland were once covered in floating sea ice, home to a variety of different cold-adapted animals, including polar bears<\/a>, walruses<\/a>, narwhals<\/a> and seals.\u00a0<\/p>\n However, in recent decades sea levels have been on the decline \u2013 in Southeast Greenland summer sea ice has essentially vanished since 2003. This has had profound effects on the already fragile Arctic ecosystem, reducing the size of available habitat, altering migration routes, and leading many species towards potentially irreversible decline.<\/p>\n Top image: Not all of Greenland\u2019s glaciers flow into the ocean, around 10% of the landmass\u2019 ice edge is currently bordered by freshwater lakes known as ice-marginal lakes. Credit: Connie Harpur<\/p>\n More wildlife stories from around the world<\/p>\n","protected":false},"excerpt":{"rendered":"Every year since 2002, Greenland has lost 264 gigatons of ice, causing sea levels to rise by 0.8mm…\n","protected":false},"author":2,"featured_media":594533,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[64,63,75,128],"class_list":{"0":"post-594532","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-au","9":"tag-australia","10":"tag-environment","11":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/594532","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=594532"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/594532\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/594533"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=594532"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=594532"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=594532"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Glaciers](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/04\/Glaciers-draining-into-ice-marginal-lakes-seen-in-Copernicus-Sentinel-2-satellite-imagery.jpg\")
Two outlet glaciers draining into ice-marginal lakes, seen in Copernicus Sentinel-2 satellite imagery. Credit: Connie Harpur<\/p>\n![\"Map](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/04\/Map-of-Greenlands-glacier-locations-and-ice-sheet-regions.jpeg\")
Map of Greenland’s glacier locations and ice sheet regions involved in the study. Credit: C.M Harpur et al. 2025 Communications Earth & Environment | creativecommons.org\/licenses\/by\/4.0\/<\/p>\n