Greenland, Antarctica, melting away, accelerating

Observations from 11 satellite missions monitoring the Greenland and Antarctic ice sheets have revealed that the regions are losing ice six times faster than they were in the 1990s. If the current melting trend continues, the regions will be on track to match the “worst-case” scenario of the Intergovernmental Panel on Climate Change (IPCC) of an extra 6.7 inches (17 centimeters) of sea level rise by 2100.

The findings…are the most comprehensive assessment to date of the changing ice sheets. The Ice Sheet Mass Balance Intercomparison Exercise team combined 26 surveys to calculate changes in the mass of the Greenland and Antarctic ice sheets between 1992 and 2018…

The team calculated that the two ice sheets together lost 81 billion tons per year in the 1990s, compared with 475 billion tons of ice per year in the 2010s — a sixfold increase. All total, Greenland and Antarctica have lost 6.4 trillion tons of ice since the 1990s…

“Every centimeter of sea level rise leads to coastal flooding and coastal erosion, disrupting people’s lives around the planet,” said Andrew Shepherd [University of Leeds – led the study].

RTFA for more quantitative data. Not likely that many of our politicians will. Maybe if sufficient voters do – and act upon their understanding – we might acquire some useful politicians.

Where’s the water going? Where will the water go?


1photo1day.com

❝ There’s still much that remains unknown about the Greenland ice sheet, which at roughly 650,000 square miles is more than twice the size of Texas. The sheet, up to two miles thick, contains enough ice that, if it all melted, would raise oceans around the world by 24 feet. Precisely how the ice melts — half or more by warming on the surface, the rest by ice sheet movement toward the sea, where it melts or calves off as icebergs — can greatly affect how much and how fast the seas rise.

Greenland is currently losing an average of about 260 billion tons of ice per year; at this rate, it would contribute about two inches to sea level rise by the end of the century. This ice loss is estimated through gravity measurements by satellites, but computer models that simulate physical processes are used to estimate the surface runoff. The field study was meant to improve those models by providing on-the-ground data on the flow of meltwater.

Science, of course, isn’t invoked just to give hope – or spread fear. Facts are facts. It takes corrupt politicians to turn them into fake news. RTFA.

Scientists work from above to learn how Greenland is melting from below


Click to enlargeNASA

❝ If the climate keeps warming the way it has, Greenland may finally live up to its name…The island’s glacier-crusted surface is melting, and a lot of this is from balmier atmospheric temperatures. But as the saying goes, that’s just the tip of the iceberg. The oceans are becoming more tepid as well, and that warmer water is causing the glaciers to thaw from below.

❝ Scientists have good measurements of how much ice melts due to warmer air. And now, thanks in part to torpedo-like probes, they are getting better data on the ice being lapped away by sea water. Those submarines are part of NASA’s Oceans Melting Greenland campaign — OMG, for short. And that’s a fairly accurate acronym, because…those glaciers are melting fast…

❝ Greenland’s glacier-gouged coastline provides the deep, warm water a path to the inland ice. Ancient ice sheets carved subsurface fjords and canyons, many of which reach down to the same level as the Atlantic-Arctic currents at the continental shelf. Problem is, “the seafloor around Greenland’s coast isn’t very well known,” says Josh Willis, a climate scientist at NASA’s Jet Propulsion Laboratory and the project lead for OMG. “The location and depths of these underwater fjords and canyons have just been poorly mapped out…”

Willis and his crew have spent the past five weeks flying over Greenland’s coastline, dropping torpedo-shaped probes into the underwater fjords. These units are called…AXCTDS, or Airborne Expendable Conductivity, Temperature and Depth Sensors…

❝ Mission OMG…spans five years and will look for ocean-caused changes to Greenland’s ice sheet. This spring, the team measured glacier height with aircraft radar, comparing past and future data to ascertain which glaciers are vanishing the fastest. The subsurface torpedo work took place this fall, when Arctic sea ice was at its minimum. It was the first time underwater probes had collected data on Greenland’s continental shelf depth, salinity and temperature.

Ultimately, the group wants to know how much of Greenland’s melting is because of air temperature, and how much is caused by water. Koppes, who has worked with the OMG team, believes air temperature and ocean water will play a 50/50 role in glacial melting.

❝ OMG will need time to analyze the data and confirm, but so far they’ve encountered some surprises. “The amount of warm water was bigger than expected, and we saw it in more places than expected,” continues Willis. “Almost everywhere along the shelf where the water was deep enough, we found Atlantic water interacting with the glaciers.”…

And the stakes are high. The deep current warming turns Greenland’s 27,000 miles of coastline — a distance greater than the Earth’s circumference at the equator — into a melt factory. The island’s interior is three times the size of Texas, and holds enough frozen water to raise global sea levels by 20 feet. More than enough to drown the Maldives, Venice, and New Orleans.

RTFA for detail about how research is proceeding, understanding all the processes contributing to the increased melt.

Composite map of thawed areas under Greenland Ice Sheet


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NASA researchers have helped produce the first map showing what parts of the bottom of the massive Greenland Ice Sheet are thawed – key information in better predicting how the ice sheet will react to a warming climate.

Greenland’s thick ice sheet insulates the bedrock below from the cold temperatures at the surface, so the bottom of the ice is often tens of degrees warmer than at the top, because the ice bottom is slowly warmed by heat coming from the Earth’s depths. Knowing whether Greenland’s ice lies on wet, slippery ground or is anchored to dry, frozen bedrock is essential for predicting how this ice will flow in the future, But scientists have very few direct observations of the thermal conditions beneath the ice sheet, obtained through fewer than two dozen boreholes that have reached the bottom. Now, a new study synthesizes several methods to infer the Greenland Ice Sheet’s basal thermal state – whether the bottom of the ice is melted or not – leading to the first map that identifies frozen and thawed areas across the whole ice sheet.

Each of these methods has strengths and weaknesses. Considering just one isn’t enough. By combining them, we produced the first large-scale assessment of Greenland’s basal thermal state,” Joe MacGregor said…

MacGregor said the team’s map is just one step in fully assessing the thermal state of the bottom of Greenland’s ice sheet.

“I call this the piñata, because it’s a first assessment that is bound to get beat up by other groups as techniques improve or new data are introduced. But that still makes our effort essential, because prior to our study, we had little to pick on,” MacGregor said.

Also proving that not only are most good scientists concerned with gradual, conservative research – proven and revalued at every step – you needn’t lose your sense of humor over the process.

Radioactive waste ready to re-surface with global warming


One of eight nuclear power plants left behind under the ice and snow

In 1951, the United States government made a pact with the Danish government to begin building camps and testing sites throughout Greenland to protect themselves from arctic Soviet attacks.

Camp Century, built 125 miles inland from Greenland’s shores, was built within the ice, housing up to 200 soldiers, testing construction in the arctic, drilling some of the first ice cores and even testing secret nuclear missiles.

But in 1967, Camp Century, and other camps, were decommissioned and closed. All but the nuclear reactor cores were left, to live forever, forgotten beneath the ice. Or so they thought.

A new study published…in the journal Geophysical Research Letters says that we shouldn’t forget about the stuff, some of it toxic and radioactive, because Greenland is melting. The scientists, from York University in Toronto, estimate with a business-as-usual climate model, the site will be melting in the next 75 years. Outside experts say it could be even sooner than that.

…The scientists estimate that there are 53,000 gallons of diesel fuel, 63,000 gallons of waste water and sewage, and unknown amounts of polychlorinated biphenyls and radioactive coolant. While the site is currently under more than 100 feet of snowfall, fallen since the 1960s, the pollutants will not stay hidden forever.

With the pollutions’ reemergence, the study authors believe this could bring up questions of who is accountable for cleaning up the site. The United States built the site, with the Danish government on a Danish territory, which is now under self-rule.

“It’s a new breed of political challenge we have to think about,” lead author and climate and glacier scientist William Colgan said…

If scientists had their way, responsibility would ultimately accrue to those who put dangerous materials in place. The United States government? That’s another story. The bifurcated clown show in Congress will ultimately decide on the budget – if any – for responsible action. Regardless of which party sits in the White House.

Given our nation’s track record, domestic and foreign, for action on radioactive pollution foisted on communities in the name of our “peace-loving” military – I ain’t too hopeful.

Greenland and the amazing technicolor coastline


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Greenland’s coast has never looked so vibrant, thanks to this three-image fusion from the ESA’s Sentinel-1A radar. Shades of grey represent land, while colors illustrate the changing sea-ice type over the course of two months.

For now, the Zachariae Isstrom glacier sits slightly left of the image center, but it’s been shedding five billion tons of ice every year because of climate change. Should it disappear completely, global sea level would rise by more than 1.5 feet.

Couple more excellent space photos over here.

Another Grand Canyon discovered beneath Greenland ice sheet

A previously unknown canyon has been discovered in Greenland, hidden beneath the ice. It is at least 750 kilometres long. To put that in perspective, imagine a ten kilometre wide gorge, up to 800 metres deep, running from the Southern coast of England and into Scotland. This is on the same scale as parts of the Grand Canyon.

Jonathan Bamber, who led the research, was originally mapping Greenland’s bedrock, which was previously thought to be relatively flat and smooth. “Unexpectedly, we found an enormous apparent formation,” he said. “We looked at it in more detail, and realised it was a canyon.”

The canyon, which is thought to predate glaciation, has remained hidden beneath two kilometres of ice for more than four million years. It has the characteristics of a meandering river channel, an ancient river system that Bamber thinks hasn’t been significantly modified by ice cover.

It is almost twice the length of the Grand Canyon, half as deep but almost as wide, and certainly the only feature in Greenland this long…

“This really is quite remarkable,” Bamber said. “In an age when you have Google street view covering the entirety of the inhabited world, when virtually every house is mapped. In this context, to discover a geological feature of such scale is astonishing…”

“We think the canyon is an efficient conduit for ice-melt from the glacier. If you want to model glacial movement – something that is ever more crucial due to global warming – then knowing about such topography is very important.”

The discovery shouldn’t affect our forecasts for future sea level in itself, but it does highlights that we still don’t know everything about the surface of our own planet.

Unexpected discoveries always lurk in the back of the mind of any researcher. It surely is a gas when something like this pops into focus and changes from anomalous shadow to a discrete discovery.

Wreckage of Coast Guard rescue plane from 1942 found


Petty Officer First Class Benjamin Bottoms

In November 1942, a US Coast Guard plane set forth on a daring rescue over the frozen tundra of Greenland, in search of a US Army Air Forces crew who had crashed during a search mission.

In a single-engine Grumman Duck aircraft, Lieutenant John Pritchard Jr. and his radioman, Petty Officer 1st Class Benjamin Bottoms, a

Massachusetts-based airman, made an unprecedented landing on the forbidding ice cap to rescue two stranded members of the B-17’s crew. But the next day, after trying to save a third man, the plane crashed in whiteout conditions, leaving no survivors. Their bodies were never recovered.

Seven decades later, an ­expedition has discovered debris from the lost plane, buried in a glacier near Greenland’s remote southeast coast, the Coast Guard said Monday.

In August, using ground-penetrating ­radar and metal ­detectors, the 17-member expedition team found black cables consistent with wiring from the aircraft nearly 40 feet below the surface. Additional wreckage was later discovered, confirming the find.

The discovery culminated years of painstaking search for the legendary rescue plane.

“The three men aboard this aircraft were heroes who made the ultimate sacrifice for their country,” said Commander Jim Blow of the Coast Guard Office of Aviation Forces and a member of the expedition. “By finding the aircraft, we have begun to repay our country’s debt to them.”

Read the whole tale. Worth remembering. Worth reflecting upon.

I grew up during that war. It was the last war the United States fought – that I would have volunteered for had I been old enough. Many of my [older] relatives volunteered. My best friend successfully lied about his age – and volunteered.