Greenland's glaciers are being ravaged by warming-induced tides, creating vast cavities

A new study has found that daily tides, fueled by warmer water, have eaten away at the bottom of a major glacier in Greenland, creating a hole taller than the Washington Monument and accelerating the glacier's retreat. The findings highlight the alarming impact of warming waters on the world's ice sheets.

Scientists are concerned that the recent discovery of a massive hole in Greenland's glacier, caused by warming-stoked tides, could be more widespread than previously thought. This has raised concerns about the accuracy of earlier projections regarding melting rates on the planet's fragile ice sheets.

Melting rates on the world's vulnerable ice sheets may have been previously underestimated as a recent study reveals the rapid melt observed in the Petermann Glacier in the far northwest of Greenland. If the phenomenon is occurring in other parts of Greenland and the Antarctic ice sheet, global ice loss and sea-level rise may accelerate at twice the previous estimates, according to the study published in Monday's Proceedings of the National Academy of Sciences.

Glaciologist Eric Rignot from the University of California Irvine says, "it's bad news." The current projections of global ice loss and sea level rise are too conservative, and the rate of melting is accelerating. The new study shows that the rapid melt on Greenland's Petermann Glacier could result in twice as fast sea level rise than previously thought, and researchers worry that the phenomenon could be happening in other areas as well.

He said this newly found consequence of tidal activity "could potentially double the projections" of global melt.

A new study examines the crucial grounding line area of glaciers on ice sheets where glaciers transition from land to water. This study highlights the significance of this area for rapid ice loss and how it's also a key factor in projecting global ice melt rates.

The study found that at Petermann Glacier, which is in a remote location with no base camps and few visitors, the grounding line area is more than 0.6 miles (1 kilometer) wide, and could be as much as 3.7 miles (6 kilometers) wide.

Researchers previously believed that daily tides didn't have much impact on melting, assuming that the snow accumulating on the glacier would offset the effects of tides. However, according to Eric Rignot, a glaciologist at the University of California Irvine and study author, this notion was proved incorrect during his expedition to the Petermann Glacier.

Warming ocean tides, intensified by climate change, have become a potent mechanism for melting glaciers, as demonstrated by a new study by Eric Rignot, a glaciologist at the University of California, Irvine. The study shows that tides have caused a cavity over 600 feet tall at the grounding line of Greenland's Petermann Glacier, with a melt rate 50% higher than previously predicted. This suggests that previous models may have underestimated the impact of tidal activity on global ice loss and sea-level rise.

Melting in the remote Petermann Glacier in Greenland has accelerated in recent years, possibly due to warm water from the North Atlantic reaching it from underneath. A study led by glaciologist Eric Rignot found that daily tides stoked by increasingly warm water caused a cavity more than 600 feet tall at the glacier's grounding line. This could double projections of global melt and sea level rise. Rignot is currently exploring Petermann to get more ground-based measurements and has noted the glacier's movements, likening it to a living thing.

Rignot described Petermann Glacier as a living thing, with loud noises coming from deep inside cracks forming. He is exploring the glacier to get more ground-based measurements using ultrasound to study the recent changes seen via satellite.

According to Greenland ice researcher Jason Box of the Geological Survey of Denmark and Greenland, who was not involved in the study, Rignot's technique is clever and the study makes sense. The findings show that the delivery of ocean heat to tidewater glacier grounding lines has a potent destabilizing effect, he said.

Box, a Greenland ice researcher at the Geological Survey of Denmark and Greenland, praised the study's methodology and described Rignot's technique as clever. Box, who uses a different approach to estimate the amount of ice that is no longer supplied by glaciers and is likely to melt, dubbed as "zombie ice" estimated that 434 billion metric tons of ice on Petermann are already committed to melting. This underscores the urgency to address climate change and reduce greenhouse gas emissions to prevent further melting of the world's ice sheets and rising sea levels.

According to Pennsylvania State University glaciologist Richard Alley, who was not involved in the study, the findings provide compelling evidence that climate models must incorporate the effects of tides in the interior of glaciers. Failure to do so could lead to underestimations of future sea level rise.