 The rapid thinning , acceleration and retreat of Helheim , Jakobshavns and Kangerdlugssuaq glaciers in Greenland , all in close association with one another , suggests a common triggering mechanism , such as enhanced surface melting due to regional climate warming or a change in forces at the glacier front . The enhanced melting leading to lubrication of the glacier base has been observed to cause a small seasonal velocity increase and the release of meltwater lakes has also led to only small short term accelerations . The significant accelerations noted on the three largest glaciers began at the calving front and propagated inland and are not seasonal in nature . Thus , the primary source of outlet glacier acceleration widely observed on small and large calving glaciers in Greenland is driven by changes in dynamic forces at the glacier front , not enhanced meltwater lubrication . This was termed the Jakobshavns Effect by Terence Hughes at the University of Maine in 1986 . Indeed , a study published in 2015 on glacial underwater topography at 3 sites found cavities , due to warm subglacial water intrusion , which has been identified as a possible dominant force for ablation ( surface erosion ) . Thus , suggests ocean temperature controls ice sheet surface runoff at specific sites . These findings also show that models underestimate the sensitivity of Greenland glaciers to ocean warming and resulting ice sheet runoff . Hence , without better modelling , new observations suggest that past projections of sea level rise attribution from the Greenland Ice Sheet require upward revision . 
