Archives par mot-clé : Antarctic

The Increasing Surface Mass Balance of Two Antarctic Glaciers

by Engel, Z.  et al., December 6, 2018 in CO2Sci/J.ofGlaciology


The polar regions of the Earth have long been depicted as canary-in-the-coal-mine sentinels of climate change, given that climate models project that CO2-induced global warming will manifest itself here, first and foremost, compared to other planetary latitudes. Consequently, researchers are frequently examining the Arctic and Antarctic for evidence of recent climate change.

Clearly, as demonstrated here and in other studies (see, for example, The Antarctic Peninsula: No Longer the Canary in the Coal Mine for Climate Alarmists and the references therein) there is a canary in the Antarctic alright, but it is alive and well. And these counter-observations do not bode well for climate models and their projections of CO2-induced global warming.

Figure 1. Surface mass-balance records for glaciers around the northern Antarctic Peninsula. Source: Engel et al. (2018).

Antarctic temperatures recently plunged close to the theoretically coldest achievable on Earth! David Middleton

by David Middleton, November 13, 2018 in WUWT


This story was previously discussed here at WUWT… But, why wasn’t this headline news in the Washington Post, New York Times, etc.?  Yes… That was a rhetorical question.

Comparisons with nearby automated weather stations suggest that air temperatures during these events are near −94 ± 4 °C or about −138 F. Ultracold conditions (below −90 °C) occur more frequently when the Antarctic polar vortex is strong. This temperature appears to be about as low as it is possible to reach, even under clear skies and very dry conditions, because heat radiating from the cold clear air is nearly equal to the heat radiating from the bitterly cold snow surface.

Relics of ‘lost continents’ hidden under Antarctica are revealed by satellite images after scientists track 200 million years of tectonic plate shifts

by H. Pettit, November 9, 2018 in MailOnline


  • Images reveal a timeline of the ancient landmasses buried beneath Antarctica
  • They were taken by the long-dead Gravity field and Ocean Circulation Explorer 
  • The ESA satellite collected data on Earth’s gravitational pull

  • The study revealed that West Antarctica (green) has a thinner crust than East Antarctica (blue), which has a ‘family likeness to Australia and India’

New Science: Arctic AND Antarctic Sea Ice More Extensive Today Than Nearly All Of The Last 10,000 Years

by K. Richard, October 18, 2018 in NoTricksZone


It is often claimed that modern day sea ice changes are “unprecedented”, alarming, and well outside the range of natural variability.  Yet scientists are increasingly finding that biomarker proxies used to reconstruct both Arctic and Antarctic sea ice conditions since the Early Holocene reveal that today’s sea ice changes are not only not unusual, there is more extensive Arctic and Antarctic sea ice during recent decades than there has been for nearly all of the last 10,000 years.

Retracing Antarctica’s glacial past

by Louisiana State University, September 25, 2018 in ScienceDaily


More than 26,000 years ago, sea level was much lower than it is today partly because the ice sheets that jut out from the continent of Antarctica were enormous and covered by grounded ice — ice that was fully attached to the seafloor. As the planet warmed, the ice sheets melted and contracted, and sea level began to rise. Researchers have discovered new information that illuminates how and when this global phenomenon occurred.

More recently in 2002, in the northern part of Antarctica called the Antarctic Peninsula, the Larsen Ice Shelf collapsed. The collapse of this ice shelf quickly led to inland glaciers buttressed by the Larsen Ice Shelf to break up and melt. Scientists have thought that a similar process could have occurred when the Ross Ice Shelf collapsed thousands of years ago in the West Antarctic Ice Sheet.

However, Bart and colleagues from the University of South Florida, Auburn University and the Polish Academy of Sciences found that there was a centuries-long delay from when the Ross Ice Shelf collapsed and the grounded ice began to contract. In the Ross Sea, the delay was between 200 to 1,400 years later. This new information adds a layer of complexity for sea level rise computer simulations and predictions.

A new volcanic province: an inventory of subglacial volcanoes in West Antarctica

by M. Van Wyk De Vries et al., August 16, 2018 in Geol.Soc.London


Abstract: The West Antarctic Ice Sheet overlies the West Antarctic Rift System about which, due to the comprehensive ice cover, we have only limited and sporadic knowledge of volcanic activity and its extent. Improving our understanding of subglacial volcanic activity across the province is important both for helping to constrain how volcanism and rifting may have influenced ice-sheet growth and decay over previous glacial cycles, and in light of concerns over whether enhanced geo- thermal heat fluxes and subglacial melting may contribute to instability of the West Antarctic Ice Sheet. Here, we use ice-sheet bed-elevation data to locate individual conical edifices protruding upwards into the ice across West Antarctica, and we propose that these edifices represent subglacial volcanoes. We used aeromagnetic, aerogravity, satellite imagery and databases of confirmed volca- noes to support this interpretation. The overall result presented here constitutes a first inventory of West Antarctica’s subglacial volcanism. We identified 138 volcanoes, 91 of which have not previously been identified, and which are widely distributed throughout the deep basins of West Antartica, but are especially concentrated and orientated along the >3000 km central axis of the West Antarctic Rift System.

Multiple NASA Studies Confirm Bedrock Heat Flow Behind Melting Polar Ice, Not Global Warming

by James E. Kamis, August 7, 2018 in ClimateChangeDisatch


In what amounts to dissension from National Aeronautics and Space Administration (NASA) climate change policy, a series of just-released studies by working-level scientists prove that geological and not atmospheric forces are responsible for melting of Earth’s polar ice sheets.

Volcanic Heat Found Under Antarctica’s Fastest-Melting Glacier

by M.  Bastach, June 28, 2018 in ClimateChangeDispatch


A group of scientists at the University of Rhode Island stumbled on something unexpected when analyzing data brought back from a 2014 expedition to western Antarctica.

Scientists found an abundance of the noble gas Helium-3, indicating there is a volcanic heat source beneath the Pine Island glacier — the fastest melting glacier in the South Pole. The findings were published in a study in the journal Nature Communications.

“When you find helium-3, it’s like a fingerprint for volcanism. We found that it is relatively abundant in the seawater at the Pine Island shelf,” chemical oceanographer Brice Loose, the study’s lead author, said in a statement.

See also here (National Science Foundation) and here

 

Worse than they thought: Antarctica actually colder than scientists once believed

by Anthony Watts, June 25, 2018 in AGU/WUWT


From the AGU and the “but, but, the continent is melting!” department.

COLDEST PLACE ON EARTH IS COLDER THAN SCIENTISTS THOUGHT

WASHINGTON — Tiny valleys near the top of Antarctica’s ice sheet reach temperatures of nearly minus 100 degrees Celsius (minus 148 degrees Fahrenheit) in the winter, a new study finds. The results could change scientists’ understanding of just how low temperatures can get at Earth’s surface, according to the researchers.

Scientists announced in 2013 they had found the lowest temperatures on Earth’s surface: Sensors on several Earth-observing satellites measured temperatures of minus 93 degrees Celsius (minus 135 degrees Fahrenheit) in several spots on the East Antarctic Plateau, a high snowy plateau in central Antarctica that encompasses the South Pole. But the researchers revised that initial study with new data and found the temperatures actually reach minus 98 degrees Celsius (minus 144 degrees Fahrenheit) during the southern polar night, mostly during July and August.

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Study provides less gloom and doom about Antarctica

by Anthony Watts, June 22, 2018 in WUWT


Antarctic ice sheet is melting, but rising bedrock below could slow it down

An international team, led by DTU Space at the Technical University of Denmark with Colorado State University, has found that the bedrock below the remote West Antarctic Ice Sheet is rising much more rapidly than previously thought, in response to ongoing ice melt.

The study, “Observed rapid bedrock uplift in the Amundsen Sea Embayment promotes ice-sheet stability,” reveals new insights on the geology of the region and its interaction with the ice sheet and is published in the journal Science. The authors noted that the findings have important implications in understanding and predicting the stability of the ice sheet and Earth’s rising sea levels.

NASA glaciologist Jay Zwally puts the hammer down: ‘Antarctica is gaining ice’

by Michael Bastach, June 15, 2018 in A. Watts WUWT


A new paper about to be in press, comes at the end of a flurry of papers and reports published this week that claims Antarctica was losing ice mass. Zwally says ice growth is anywhere from 50 gigatons to 200 gigatons a year. NASA glaciologist Jay Zwally says his new study will show, once again, the eastern Antarctic ice sheet is gaining enough ice to offset losses in the west.

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Antarctic Ice Loss Tripled, from near zero to an extremely tiny number! (Nobody mention those volcanoes)

by JoNova, June 15, 2018


Quick — tax the magma

It’s another round of Antarctic Doom about next to nothing. In April Antarctica’s ice was melting five times faster than usual. Now it’s losing ice three times faster in the last five years than the 15 before that! What you won’t hear is how the Antarctic ice cap has 29 million cubic kilometers of ice and has been there for 30 million, mostly warmer, years. You also won’t hear how Antarctica was warmer in Roman Times, or that the  Antarctic Peninsula has cooled by almost 1 degree.

You also won’t hear a word about any volcanoes

The new paper has zero mentions of the word. But other scientists have published plenty of papers describing how the West Antarctic zone is being warmed from below by 1200 degrees of magma. According to scientist Dustin Schroeder and co,  it is as if the Thwaites Glacier in West Antarctic is sitting on a “stovetop burner”.[1]  His words. Thwaites Glacier,, smack in the middle of the warming is being melted from below by geothermal heat. Then there is the large blob of superheated rock 60 miles below West Antarctica. The researchers use the phrase “like a blow-torch”….  Capping it off, only last year 91 new volcanoes were discovered 2km underneath the West Antarctic Rift. That’s new, as in, we didn’t know they were there.

Follow the reasoning, either a trace gas 10 kilometers up is causing some spots of Antarctica to warm and other parts to cool, or hot magma at 1,200C is. What’s more likely?

NSF study: ‘…current carbon dioxide levels are not enough to destabilize the land-based ice on Antarctica’

by Anthony Watts, June 15, 2018 in WUWT


We covered this yesterday, but today the official press release came out, so worth covering again. Via Eurekalert


Land-based portion of massive East Antarctic ice sheet retreated little during past eight million years

But increases in atmospheric carbon dioxide levels could affect stability and potential for sea level rise

NATIONAL SCIENCE FOUNDATION

Large parts of the massive East Antarctic Ice Sheet did not retreat significantly during a time when atmospheric carbon dioxide concentrations were similar to today’s levels, according to a team of researchers funded by the National Science Foundation (NSF). The finding could have significant implications for global sea level rise.

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Japanese Meteorological Agency Corrects Antarctic’s Long-Term Sea Ice Growth Trend Upwards

by P. Gosselin, June 01, 2018 in NoTricksZone


The Global Environment and Marine Department of the Japanese Meteorological Agency recently corrected the long term trend in the annual mean sea ice extent in the Antarctic area: from 0.015 x 106 km2per year to 0.019 x 106 km2 per year on 11 May 2018.

That’s more than a 25% adjustment (15,000 sq. km to 19,000 sq km). So while chunks the size of Manhattans may break off from time to time, about 300 Manhattans of new ice gets added annually.

The report notes that in the Antarctic Ocean: “the annual maximum and annual mean sea ice extents have shown a long-term trend of increase since 1979”.

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