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.
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.
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.
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
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.
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.
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.
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
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.
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”.
by Lovell, A.M. et al., 2017 in CO2Science, May 24, 2018
In describing their findings, Lovell et al. state that “between 1972 and 2013, 36% of glacier termini in the entire study area advanced and 25% of glacier termini retreated, with the remainder showing no discernible change outside of the measurement error (± 66 m or ± 1.6 m yr-1) and classified as ‘no change'” (see figure below). Although there were some regional differences in glacier termini changes, these regions over the last four decades were more closely linked to non-climatic drivers, such as terminus type and geometry, than any obvious climatic or oceanic forcing.”
See aslo : Terrifying Times For Climate Alarmists
by J.E. Kamis, May 7, 2018 in ClimateChangeDispatch
The inclusion of the here-termed West Antarctic Volcano and Fault Belt into the Pacific Ring of Fire will raise scientific awareness concerning the idea, as per the Plate Climatology Theory, that geologically induced heat flow is the root cause of many anomalous changes in Antarctica’s ecosystems, oceans, climate, and ice masses.
by P. Homewood, May 2, 2018 in NotaLotofPeopleKnowThat
For several decades now, Antarctica has not been cooperating with the “global” warming narrative, as the continent as a whole has not been warming.
Several scientific papers have been published recently that document the lack of an anthropogenic warming signal for the Antarctic continent or the surrounding ocean, as well as the dominance of natural variability (…)
by Julius Sanks, April 16, 2018 in WUWT
When discussing climate with people who do not have technical backgrounds, I have learned much of the climate discussion is a foreign language to them.
So, I take them through a few examples of how much energy is involved and how miniscule human activity is by comparison. Done properly, this lets a non-STEM person grasp the huge amounts of energy involved.
One of my favorites is Anthony’s essay that debunks the Hiroshima equivalent alarmism:
British Antarctic Survey, April 9, 2018
Presenting this week (Monday 9 April 2018) at the European Geosciences Union (EGU) meeting in Vienna, an international team, led by British Antarctic Survey, describes how analysis of 79 ice cores collected from across Antarctica reveals a 10% increase in snowfall over the last 200 years. This is equivalent to 272 giga tonnes of water – double the volume of the Dead Sea.
Lead author and ice core scientist Dr Liz Thomas from British Antarctic Survey explains: (…)