The vast ice shelves extending from the glaciers in North Greenland have witnessed a remarkable decline over the past five decades. Researchers have determined that these frozen extensions have lost over a third of their volume, with three of them succumbing to complete collapse. A study published in Nature Communications employed satellite imagery and climate data to reveal that the ice shelves in this region have shrunk by more than 35% since 1978, primarily attributed to the warming of the surrounding ocean. This raises alarm as Greenland harbours an immense quantity of ice, and its complete melting could elevate sea levels by nearly seven feet, potentially leading to catastrophic consequences.
According to the report, the Greenland ice sheet has contributed 17.3% of the observed rise in sea level in the period 2006-2018 and has thus become the second largest contributor after ocean thermal expansion.
Between 2000 and 2020, there was a widespread increase in basal melt rates that closely followed a rise in ocean temperature. These glaciers are showing a direct dynamical response to ice shelf changes with retreating grounding lines and increased ice discharge.
As per the release, these results were obtained using field observations, aerial photography, and satellite data combined with regional climate models.
"The observed increase in melting coincides with a distinct rise in ocean potential temperature, suggesting a strong oceanic control on ice shelf changes," researchers said in the study. "We are able to identify a widespread ongoing phase of weakening for the last remaining ice shelves in this sector."
