Everything at the Membrane Domain
Around the world glaciers are melting at an alarming rate. The World Glacier Monitoring Service publishes a survey of the mass changes from glaciers.
In their latest survey, the found “The average mass balance of the glaciers with available long-term observation series around the world continues to be negative, with tentative figures indicating a further thickness reduction of 1.1 meters water equivalent (m w.e.) during the hydrological year 2015.”
Australia’s ABC news reports:
Scientists hope to discover how warm water is reaching one of the world’s largest glaciers, causing it to melt rapidly.
Lead author Steve Rintoul said it was the first time scientists had been able to test the hypothesis that warm ocean waters were driving the glacier’s thinning.
“We knew the Totten has been thinning faster than other glaciers in East Antarctica, but nobody has known exactly why until we took these measurements,” he said.
“We found that warmer ocean water is reaching the cavity through this channel at temperatures capable of melting the ice shelf at the point where it meets ground.
Dr Rintoul said it was important to be able to predict the Totten glacier’s future behaviour, because it contained enough sea ice to raise global sea levels by about 3.5 metres.
“So the real importance of the research is that it helps provide some clues about how sea level might change in the future.”
The publication of the research today comes as scientists make their way back to the Totten glacier, where they hope to find more clues about what controls the amount of warm water reaching the glacier.
A team of about 30 scientists, technicians and PhD students left Hobart on December 8 and plan to arrive at the glacier in late December.
Dr. Rintoul said their goal was to learn more about the pathways that bring the warm water up from the deep ocean.
“Understanding the physical processes delivering heat to the ice shelf will help us assess the vulnerability of the East Antarctic ice sheet to future changes in the Southern Ocean,” he said.
“What we have shown is that warm water reaches the glacier. What we need to know is what’s going to happen in the future.
Dr. Tas van Ommen from the Australian Antarctic Division said it would be concerning to see an increase in the Totten glacier’s natural melt rate.
“If its natural melt rate was to increase because of changes in ocean circulation, that would then add to the sea level rise that we see from glaciers already melting in Antarctica, particularly in the West.
“So we are concerned to track that and to be able to predict what might happen in the future.”
The BBC reports that the glaciers on Mount Everest are melting so fast that they are causing large lakes. No only do the lakes make it difficult to scale the mountain, but if the ice dams break up it could cause massive flooding.
“A decade or so ago, there were individual ponds on the Khumbu glacier but in the past five years or so they have begun to get larger and join up,” said Ann Rowan, who led the field study team from the universities of Sheffield and Leeds.
“Particularly, on the left hand side of the lower reaches of the glacier, there is a series of about seven or eight large ponds that are now starting to link and form a big chain,” she told the BBC.
“There is water flowing from the upper part of the glacier through the series of these ponds and that is going to encourage them to join up.
“At present, the glacier appears to be disintegrating, and may form a few large and potentially hazardous lakes on the glacier surface.”
A NASA study published in the journal Science found a glacier in Greenland broke apart. “The consequences will be felt for decades to come.”
“North Greenland glaciers are changing rapidly,” said lead author Jeremie Mouginot, an assistant researcher in the Department of Earth System Science at the University of California, Irvine. “The shape and dynamics of Zachariae Isstrom have changed dramatically over the last few years. The glacier is now breaking up and calving high volumes of icebergs into the ocean, which will result in rising sea levels for decades to come.”
The scientists determined the bottom of Zachariae Isstrom is being rapidly eroded by warmer ocean water mixed with growing amounts of meltwater from the ice sheet surface. “Ocean warming has likely played a major role in triggering [the glacier’s] retreat,” Mouginot said, “but we need more oceanographic observations in this critical sector of Greenland to determine its future.”
“Zachariae Isstrom is being hit from above and below,” said the study’s senior author Eric Rignot, Chancellor’s Professor of Earth system science at UCI, and Joint Faculty Appointee at JPL. “The top of the glacier is melting away as a result of decades of steadily increasing air temperatures, while its underside is compromised by currents carrying warmer ocean water, and the glacier is now breaking away into bits and pieces and retreating into deeper ground.”
“Not long ago, we wondered about the effect on sea levels if Earth’s major glaciers in the polar regions were to start retreating,” Rignot noted. “We no longer need to wonder; for a couple of decades now, we’ve been able to directly observe the results of climate warming on polar glaciers. The changes are staggering and are now affecting the four corners of Greenland.”
The U.N.’s panel on global warming warns:
Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent (high confidence).