Peak Oil News and Message Boards

Using a constellation of satellites, we detect the evolution of ice velocity, ice thinning, and grounding line retreat of Thwaites Glacier from 1992 to 2017

dohboi wrote:From the abstract to the paper:

Using a constellation of satellites, we detect the evolution of ice velocity, ice thinning, and grounding line retreat of Thwaites Glacier from 1992 to 2017

http://advances.sciencemag.org/content/5/1/eaau3433

There has been no adequate interferometric synthetic aperture radar (InSAR) data after 2011 to observe the grounding line retreat (13, 14).

dohboi wrote:It is my understanding that the grounding line is different than the development of the explosively growing cavity within the glacier.

If you have a different view, perhaps you could elucidate.

dohboi wrote:Arguments from incredulity are...well...not really arguments, just hand waving. Go wave your hands elsewhere, please

https://www.logicallyfallacious.com/too ... ncredulity

jawagord wrote:Antarctica is 14,000,000 square kilometres of ice averaging 1.5+ kilometres thick, the hole in the Thwaites glacier is supposedly 2/3 size of Manhattan or 40 square kilometres. Do the math folks, doomsday sea level rise isn’t happening in your lifetime or your children’s or your grand children’s. Look at the map, Antarctica is the size of the US+Mexico, can you even identify Manhattan or Thwaites in all that expanse?

https://www.nasa.gov/mission_pages/iceb ... ca-US.html

Thwaites Glacier (75°30′S 106°45′W) is an unusually broad and fast Antarctic glacier flowing into Pine Island Bay, part of the Amundsen Sea, east of Mount Murphy, on the Walgreen Coast of Marie Byrd Land.[1] Its surface speeds exceed 2 km/yr near its grounding line, and its fastest flowing grounded ice is centred between 50 and 100 km east of Mount Murphy. It was named by ACAN[2] after Fredrik T. Thwaites, a glacial geologist, geomorphologist and professor emeritus at the University of Wisconsin–Madison.[3] Thwaites Glacier drains into West Antarctica’s Amundsen Sea and is closely watched for its potential to raise sea levels.[4]
Along with Pine Island Glacier, Thwaites Glacier has been described as part of the "weak underbelly" of the West Antarctic Ice Sheet, due to its apparent vulnerability to significant retreat. This hypothesis is based on both theoretical studies of the stability of marine ice sheets and recent observations of large changes on both of these glaciers. In recent years, the flow of both of these glaciers has accelerated, their surfaces lowered, and the grounding lines retreated.

jawagord wrote:From now on I won’t call climate change ‘junk science’ i’ll rename it as referenced by the link in your post, ‘Crackpot Science”!

Exception: We can't possibly entertain every crackpot with crackpot ideas. People with little credibility or those pushing fringe ideas need to provide more compelling evidence to get the attention of others.

Six berths on the 120m-long icebreaker have been confirmed for UK researchers, who will work alongside up to 600 international scientists and crew from 17 countries as part of this major international effort to better understand the fastest changing environment on the planet.
This year-long study will see the RV Polarstern move with the current in the ice across the central Arctic Ocean from September 2019 to September 2020.
Spearheaded by Germany's Alfred Wegener Institute (AWI), the €120 million Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) mission aims to answer some of the biggest scientific questions about the Arctic, including investigating why the region is warming twice as fast as the global average.
This is among the first missions of its kind since the 1890s, when Norwegian explorer Fridtjof Nansen attempted to reach the North Pole by drifting in a ship locked in ice. Nansen had to abandon his ship when he realised he had gone off track, but the ship itself made it across the ice cap intact and the expedition resulted in breakthrough scientific discoveries about the Arctic and weather patterns.
More than a hundred years later, the MOSAiC research aims to deliver a step change in our understanding of the Arctic climate system and how it affects global climate models. NERC has partnered with the Department for Business, Energy & Industrial Strategy (BEIS), who have provided funding for ship berth fees on the MOSAiC expedition.
NERC has now awarded grants worth £1·8 million to six research proposals that will each utilise a two-month berth on the German research vessel.

Considerable uncertainty remains in projections of future ice loss from West Antarctica. Since the 1990s, satellites have shown accelerating ice loss driven by ocean change in five neighbouring glacier catchments, including Thwaites Glacier, that drain more than one third of the West Antarctic Ice Sheet (WAIS). The rate of ice loss there doubled in six years and now accounts for about 10% of global sea-level rise. The most rapid ice loss is currently from Pine Island Glacier, which has been the focus of the NERC Ice Sheet Stability Programme and National Science Foundation (NSF)-funded science. Recent studies indicate the greatest risk for future rapid sea-level rise now arises from Thwaites Glacier.
NERC and the NSF are co-funding a research programme which aims to substantially improve both decadal and longer-term (century-to multi-century) projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica.

Newfie wrote:Here’s a good short NASA paper about the Jacobshaven glacier in Greenland. It’s a very large Northern glacier but very small Compared to the Antarctic glaciers which are really more entire ice fields.

Other research has shown the same phenomenon in Greenland glaciers, the ice front is eroded from underneath by relatively warm water. Remember that water has it highest density at about 2°. Then it rises in the water colum, that’s why ice floats. So the water under the ice is warmer. They also now know melt water from the surface bores through the ice sheet and races out the fjords under the glacier, warmish water under the ice errodes the ice.

In a paper published this month by the American Geophysical Union, researchers say sharp rises in levels of methane – which is a powerful greenhouse gas – have strengthened over the past four years. Urgent action is now required to halt further increases in methane in the atmosphere, to avoid triggering enhanced global warming and temperature rises well beyond 2C.

“What we are now witnessing is extremely worrying,” said one of the paper’s lead authors, Professor Euan Nisbet of Royal Holloway, University of London. “It is particularly alarming because we are still not sure why atmospheric methane levels are rising across the planet.”

Natural chemicals in the atmosphere – which help to break down methane – may be changing because of temperature rises, causing it to lose its ability to deal with the gas.

Our world could therefore be losing its power to cleanse pollutants because it is heating up, a climate feedback in which warming allows more greenhouse gases to linger in the atmosphere and so trigger even more warming.

Increasing spring rains in the Arctic could double the increase in methane emissions from the region by hastening the rate of thawing in permafrost, new research suggests.

...

"Our results emphasize that these permafrost regions are sensitive to the thermal effects of rain, and because we're anticipating that these environments are going to get wetter in the future, we could be seeing increases in methane emissions that we weren't expecting," said the study's lead author, Rebecca Neumann, a civil and environmental engineering professor at the University of Washington. The study appears in the journal Geophysical Research Letters.

...
In the new study, Neumann and colleagues tracked rainfall, soil temperature and methane emissions at a thawing permafrost bog approximately 20 miles southwest of Fairbanks, Alaska, from 2014 through 2016.

In 2016, a year marked by early spring rain, the team saw soil temperatures at the edge of the bog begin to increase 20 days earlier than usual. Methane emissions across the bog were 30 percent higher than in the two previous years which did not have early spring rains.

The study projects that as the temperature and precipitation in the region continue to increase, the rate of increase in methane emissions from the region may be roughly twice that of current estimates that don't account for rainfall.