British explorers in West Antarctica reported glacier movement in the region has picked up by a startling seven percent this season, a development, they said, which could lead to a significant rise in sea level.
The biggest of the glaciers, the Pine Island Glacier, is causing the most concern.
The reason does not seem to be warming in the surrounding air.
One possible culprit could be a deep ocean current that is channelled onto the continental shelf close to the mouth of the glacier. There is not much sea ice to protect it from the warm water, which seems to be undercutting the ice and lubricating its flow
Julian Scott, however, thinks there may be other forces at work as well.
Much higher up the course of the glacier there is evidence of a volcano that erupted through the ice about 2,000 years ago and the whole region could be volcanically active, releasing geothermal heat to melt the base of the ice and help its slide towards the sea.
Read more on the BBC website: ‘Antarctic glaciers surge to ocean’
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
There are three possibilites for the “surge”: Increased snow fall at the source/top of the glacier which increases pressure to flow faster, increased meltwater under the glacier which reduces friction, or a removal of some barrier abetting movement (i.e. reduction in sea-ice).
The sea-ice has not noticeably decreased (and in fact has increased recently). This then leaves the first two possibilities as most likely. Surface melting is not a contender as the atmospheric temp over the glacier ALWAYS below zero C.
Related stuff:
http://www.sciencemag.org/cgi/content/abstract/291/5505/862?ijkey=lhOzSHR0xMxxg&keytype=ref&siteid=sci
http://www.guardian.co.uk/science/2001/feb/02/uknews.glaciers
http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=341
Paul: this story has been developing for a while
See “The ice man cometh”
Volcanoes eh? Well, well …
Davey … bullseye?
http://igloo.atmos.uiuc.edu/ANTARCTIC/TRENDS/IMAGES/annual.trend.1958-2002.gif
More on ice
see Michiel van den Broeke
http://www.phys.uu.nl/
2008 Rignot – Nature Publishing Group
http://www.phys.uu.nl/~broeke/home_files/MB_pubs_pdf/2008_Rignot_NatGeo.pdf
Nah it’s your recent CSIRO-French transect reporting warming ocean gnawing the front off.
Remember! http://www.csiro.au/files/files/pisg.mp3
and here’s how it works
http://www.sciam.com/article.cfm?id=the-unquiet-ice&page=5
Of course it’s not gonna melt – it’s gonna slide.
We’ll all going to drown. Repent – the end is nigh.
“The team found that the net loss of ice mass from Antarctica increased from 112 (plus or minus 91) gigatonnes a year in 1996 to 196 (plus or minus 92) gigatonnes a year in 2006. A gigatonne is one billion metric tons, or more than 2.2 trillion pounds. These new results are about 20 percent higher over a comparable time frame than those of a NASA study of Antarctic mass balance last March that used data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment. This is within the margin of error for both techniques, each of which has its strengths and limitations.
Rignot says the increased contribution of Antarctica to global sea level rise indicated by the study warrants closer monitoring.
“Our new results emphasize the vital importance of continuing to monitor Antarctica using a variety of remote sensing techniques to determine how this trend will continue and, in particular, of conducting more frequent and systematic surveys of changes in glacier flow using satellite radar interferometry,” Rignot said. “Large uncertainties remain in predicting Antarctica’s future contribution to sea level rise. Ice sheets are responding faster to climate warming than anticipated.”
http://www.scientificblogging.com/news_releases/study_antarctic_ice_loss_rate_nearly_matches_greenland
Paul must have missed this bleeding map
“Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by NASA and university scientists”
http://www.nasa.gov/topics/earth/features/antarctica-20080123.html
I didn’t miss it – I think we mentioned the Rignot Nature Geoscience article elsewhere.
http://www.jennifermarohasy.com/blog/archives/002694.html
Paul: I’m surprised that we are not directed in our discussions to the source of this latest report on accelerating Antarctic ice loss with appropriate maps of both ice and temperature anomalies.
“Scientists from NASA’s Goddard Space Flight Center have been working for several years to create and refine a satellite map of long-term temperature change in Antarctica. This image illustrates long-term changes in yearly surface temperature in and around Antarctica between 1981 and 2007. Places where it warmed over time are red, places where it cooled are blue, and places where there was no change are white. Image Credit: NASA Earth Observatory”
http://geology.com/nasa/antarctic-ice-sheet-melting.shtml
We shouldn’t be hunting for a sudden increase in volcano activity. Apart from the obvious comparison with Greenland’s ice loss over the same period there is clearly a general increase in ice flow round the southern continent now.
IMO geologists should be counting the increase in icebergs.
Arnost,
Yep…
I have held off from posting on this thread to see what sort of material might come up. And as expected, some substance from Arnost but the usual froth from the usual suspects. Both the article and the science is exposed as a complete crock in “Another day, another melting glacier scare” at http://ianmott.blogspot.com/
As Jennifer seems to think she is doing me a big, unappreciated, favour by providing me with a forum, I have decided to stop indulging myself at her expense. All my serious posting will now be done at a site where I can actually retrieve it easily.
One of the cornerstones of the AGW/Climate Change doom and gloom projections is the melting of the Antarctic ice-cap. Without this occurring, those multi-meter sea level rises can’t occur – and this is about the only thing that will have a significant effect on civilisation.
Lets face it, an increase of a degree or two in average temps will not do anywhere near the damage to the environment than that which we are already doing through deforestation, urbanisation, strip-mining, bottom trawling/dredging etc etc etc.
Most recent science tries very hard to find this warming trend in Antarctica – but it’s just not there.
http://www.worldclimatereport.com/wp-images/monaghan_fig1.JPG
The above is from: Monaghan, A. J., D. H. Bromwich, W. Chapman, and J. C. Comiso (2008), Recent variability and trends of Antarctic near-surface temperature, Journal of Geophysical Research, 113, D04105, doi:10.1029/2007JD009094.
http://www.agu.org/pubs/crossref/2008/2007JD009094.shtml
via World Climate Report
See also:
AR4 WG1 Chapter 3 Page 248:
“Temperatures over mainland Antarctica (south of 65°S) have not warmed in recent decades (Turner et al., 2005)”
AR4 WG1 Chapter 3 Page 317:
“In contrast to the Arctic, Antarctic sea ice does not exhibit any significant trend since the end of the 1970s, which is consistent with the lack of trend in surface temperature south of 65°S over that period.”
So there are studies that Antarctica is not warming, the IPCC reports that Antarctica is not warming, and somehow this translates into claims that “Antarctica is warming and melting” and we are all doomed to drown under multi-meter sea level rises.
To be fair, the IPCC point out that the Antarctic Aeninsula is significantly warming (see my “bullseye” link above). However, it is a long stretch that such intense localised warming is caused by a general world-wide phenomenon.
The role of volcanoes in the “surge” of the Pine Glacier is as yet supposition as scientists have only identified a past eruption. But the Seal Nunataks have been active numerous times in the last 50 years – and they are directly under the bullseye hotspot. Their, and the role of the shield volcano (which they are a part of) in the break-up of the Larsen ice-shelf is probably more than just conjecture.
http://www.volcano.si.edu/world/volcano.cfm?vnum=1900-05=
cheers
Arnost
Good post Arnost.
And of course, volcanic activity is mostly intermittent so there is no basis for any extrapolation of the current localised warming to cover longer periods or wider area.
The simmering volcanoe erupts and, having erupted, simmers on. And that should really put the whole continent, if not the southern hemisphere, to climatic bed, perchance to dream.
Yes, and keep clear of Heard Island.
“Instability of the West Antarctica Ice Sheet” Feb 27, 2008
See glacier and ice shelf photos
http://global-warming.accuweather.com/2008/02/instability_of_the_west_antarc_1.html
Webcams from Antarctica
http://www.antarctica.ac.uk/images/webcams/index.php
Cosmic rays and glacier rocks
http://www.alphagalileo.org/index.cfm?_rss=1&fuseaction=readrelease&releaseid=527457
“One of the cornerstones of the AGW/Climate Change doom and gloom projections is the melting of the Antarctic ice-cap.”
Is it ? IPCC doesn’t say so. I assume we want to talk science not newspaper grabs. Of course the criticism of the IPCC reports is that the latest on ice sheet dynamics is not included.
But don’t think melt – think slide …
Changes in ice dynamics and mass balance of the Antarctic ice sheet:
Philosophical Tranactions of the Royal Society “A”
Volume 364, Number 1844 / July 15, 2006, 1637-1655
Eric Rignot1
1 Jet Propulsion Laboratory 4800 Oak Grove Drive MS 300-319, Pasadena, CA 91109-8099, USA
The concept that the Antarctic ice sheet changes with eternal slowness has been challenged by recent observations from satellites. Pronounced regional warming in the Antarctic Peninsula triggered ice shelf collapse, which led to a 10-fold increase in glacier flow and rapid ice sheet retreat. This chain of events illustrated the vulnerability of ice shelves to climate warming and their buffering role on the mass balance of Antarctica. In West Antarctica, the Pine Island Bay sector is draining far more ice into the ocean than is stored upstream from snow accumulation. This sector could raise sea level by 1m and trigger widespread retreat of ice in West Antarctica. Pine Island Glacier accelerated 38% since 1975, and most of the speed up took place over the last decade. Its neighbour Thwaites Glacier is widening up and may double its width when its weakened eastern ice shelf breaks up. Widespread acceleration in this sector may be caused by glacier ungrounding from ice shelf melting by an ocean that has recently warmed by 0.3°C. In contrast, glaciers buffered from oceanic change by large ice shelves have only small contributions to sea level. In East Antarctica, many glaciers are close to a state of mass balance, but sectors grounded well below sea level, such as Cook Ice Shelf, Ninnis/Mertz, Frost and Totten glaciers, are thinning and losing mass. Hence, East Antarctica is not immune to changes
And again – here’s how it work – http://www.sciam.com/article.cfm?id=the-unquiet-ice&page=5
Nature Geoscience 1, 106 – 110 (2008)
Published online: 13 January 2008 | doi:10.1038/ngeo102
Recent Antarctic ice mass loss from radar interferometry and regional climate modelling
Eric Rignot1,2,3, Jonathan L. Bamber4, Michiel R. van den Broeke5, Curt Davis6, Yonghong Li6, Willem Jan van de Berg5 & Erik van Meijgaard7
Large uncertainties remain in the current and future contribution to sea level rise from Antarctica. Climate warming may increase snowfall in the continent’s interior1, 2, 3, but enhance glacier discharge at the coast where warmer air and ocean temperatures erode the buttressing ice shelves4, 5, 6, 7, 8, 9, 10, 11. Here, we use satellite interferometric synthetic-aperture radar observations from 1992 to 2006 covering 85% of Antarctica’s coastline to estimate the total mass flux into the ocean. We compare the mass fluxes from large drainage basin units with interior snow accumulation calculated from a regional atmospheric climate model for 1980 to 2004. In East Antarctica, small glacier losses in Wilkes Land and glacier gains at the mouths of the Filchner and Ross ice shelves combine to a near-zero loss of 4+- 61 Gt yr-1. In West Antarctica, widespread losses along the Bellingshausen and Amundsen seas increased the ice sheet loss by 59% in 10 years to reach 132 +- 60 Gt yr-1 in 2006. In the Peninsula, losses increased by 140% to reach 60+- 46 Gt yr-1 in 2006. Losses are concentrated along narrow channels occupied by outlet glaciers and are caused by ongoing and past glacier acceleration. Changes in glacier flow therefore have a significant, if not dominant impact on ice sheet mass balance.
So decadal influences, net effects ? Well we may speculate – but there seems to be no doubt of an ongoing and multi-decadal acceleration of Antarctic glacial output where the terminus is affected by sea temperature. Across a number of systems.
And still he does a cut and paste with vague and generalised guff. The acceleration of the PIG Pine Island Glacier from 1975 still only took the speed up to 200 metres a year in 2001.
And the numbers revealed in my link above still apply. That is, gross discharge is in the order of 3.21km3 (or Gt, if you must) from a total volume in the order of 100,000km3. The most conservative estimate of new ice deposition is 1.5km3 (Gt) leaving a net 1.71km3 annual discharge and 58,480 years for it to go away.
And the PIG is generally accepted as the fastest glacier in the region so if it will still be there in 50,000 years then the rest will be there for longer.
Also note that the PIG has a large calving every 5 years or so and this obviously produces a faster flow in the following years.
To well illustrate that you have not done your background homework (as usual).
But I can’t be bothered chasing your random newspaper diversion and the few numbers buried in your ever tedious babbly blather. You’ve not on the serious science issue here as to whether AGW is likely having an effect and instead up an overly hysterical diversionary rant – swinging at shadows that don’t exist.
The deposition is piddly compared to the loss in this case. Get real and get some serious data. Linearity is your problem.
Remember you were initially on matters polar working out how long things take to melt.
Sorry wrong model.
Slide & slip, crack, undercut, collapse and flood.
Survivor: outwit, outplay, outlast.
I’ll take Rignot over bloggers any day.
Luke: After a read through Ian’s somewhat sobering ice loss calcs on his blog I thought they were a bit “flat earth” and probably lacked proper considerations for the rising rates of change and flow “surges”. What we need to see are all the differential equations etc since I for one can’t get the old brain across the necessary mathematical stages.
Ian: Although Luke insists on us reading Rignot, I took a quick look at one of his cohorts, Michiel van den Broeke, who has done an impressive amount of work on related topics.
http://www.phys.uu.nl/~broeke/
See also “Cryosphere” – Co-Editors, Michiel Van den Broeke et al
“The Cryosphere (TC) is an international scientific journal dedicated to the publication and discussion of research articles, short communications and review papers on all aspects of frozen water and ground on Earth and on other planetary bodies.
• ice sheets and glaciers;
• planetary ice bodies;
• permafrost, river and lake ice;
• seasonal snowcover;
• sea ice;
• remote sensing, numerical modelling, in-situ and laboratory studies of the above and including studies of the interaction of the cryosphere with the rest of the climate system”
http://www.the-cryosphere.net/
A millennial perspective on Arctic warming from 14C in quartz and
plants emerging from beneath ice caps
GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L01502, doi:10.1029/2007GL032057, 2008
Rebecca K. Anderson,1 Gifford H. Miller,1 Jason P. Briner,2 Nathaniel A. Lifton,3
and Stephen B. DeVogel1
[1] Observational records show that the area of ice caps on
northern Baffin Island, Arctic Canada has diminished by
more than 50% since 1958. Fifty 14C dates on dead vegetation
emerging beneath receding ice margins document the
persistence of some of these ice caps since at least 350 AD.
In situ cosmogenic 14C in rock surfaces, and 14C in plant
macrofossils from lake-sediment cores demonstrate that the
plateau remained ice-free through the middle Holocene, but
has supported ice caps for more than 2000 of the past
2800 years. The rapid disappearance of these ice caps over
the past century, despite decreasing summer insolation,
further demonstrates the unusual character of 20th Century
warmth. Widespread ice-cap expansion ~1280 AD early in
the Little Ice Age, and intensified expansion ~1450 AD,
coincide with peak stratospheric volcanic aerosol loading and
reduced solar luminosity, suggesting that these mechanisms
may have initiated ice-cap growth, subsequently maintained
by strong positive feedbacks.
Luke avoids the numbers once again and claims the new ice formation is only a fraction of the ice discharge. But provides no substantiation, as usual.
So which parts of the basic equation are the ones that Luke can’t get his head around? And which parts of basic volume and velocity calculations does Gavin regard as “flat earth”?
Lets do this again, shall we?
Depth of ice at the grounding line 0.5km
Width of ice at the grounding line 30km
Velocity of ice at grounding line 0.200km (2001).
Velocity of ice after 7% increase 0.214km/year.
Annual discharge of ice from the PIG 3.21km3
Reported volume of ice in the PIG 100,000km3
Estimated area of the PIG = 30,000km2
Annual ice deposition on PIG @50mm/year = 1.5km3
Net discharge of ice from PIG = 1.71km3 (3.21-1.5)Required years for 20% ice volume decline = 11,696 years.
That is, it will take the equivalent of the entire duration of human civilisation for the PIG to decline to only 80% of its current volume.
Remember, the Antarctic continent must shed more than 1000km3 of ice each year to prevent a global drop in sea level.
So tell us, Luke? Which of the numerous glaciers around the world that are clearly much smaller today than their past extent, have undergone a sudden collapse? Answer, none.
This sudden collapse theory is a sham.
When faced with the hard numbers, Luke, the sad climate cargo cultist reaches into his dilly-bag for another mantra to see if he can get his aeroplane effigy off the ground. And all he can come up with is a quote from Baffin Island, on the other side of the planet!
The problem, Ian and Alex is that the linear approach (that is that every year will be roughly the same as the last) is a very poor analysis. No natural system in the world is linear, they’re all non-linear. We don’t need to show that what you have done is wrong because it’s so obvious (except to you both?). You need to examine the phenomena using differential equations. As the ice melts it will accelerate due to feedback effects. As we have seen in the Arctic.
Look at the ice mass-balance for glaciers around the world (google it) you will see that your simplistic maths are pretty poor.
Only barely relevant, Mr T. The major limit to the non-linearity of glacial flow is the fact that it involves ice, a solid, not a liquid. This means the upper portions in an extrapolation equation for ice cannot take place because it would require the ice to be semi-plastic, which it is not.
And in the context of 58,000 years, any variation from a linear equation to a non-linear one is totally irrelevant for at least the next 10 millenia.
And in any event, as the cause of the PIG’s increase in velocity is being attributed to volcanic activity, it is totally inappropriate to be extrapolating under an assumed continuous eruption. They just don’t do that on the scale needed to impact on the PIG.
This most recently reported increase in velocity is almost certainly a temporary consequence of the large calving event in 2005. It is generally accepted in the glacial studies field that they speed up and slow down in continuous cycles.
But once again, we have the climatozoa claiming that the increase in speed is an anthropogenic threat while the following reduction in speed is a consequence of natural variation. Nice work if you can find some plodder to believe you.
Ian, I was only complaining you maths was to simple, and it still is.
Also note that the scientists say that it isn’t due to Global Warming. Also note the difference between one particular glacier and the West Antarctic ice sheet.
Er, Mr T: I had the distinct impression our glacier scientists were discussing hot flushes all round down under, not volcanos.
Yes Gavin, regional warming. I was just helping Ian understand that his analysis of one glacier (which the authors suggested wasn’t due to warmth) can’t be extrapolated to the whole West Antarctic ice sheet.
High rates of sea-level rise during the last
interglacial period
Nature Geoscience VOL 1 JANUARY 2008
E. J. ROHLING1*, K. GRANT1, CH. HEMLEBEN2*, M. SIDDALL3, B. A. A. HOOGAKKER4, M. BOLSHAW1
AND M. KUCERA2
1National Oceanography Centre, European Way, Southampton SO45 5UH, UK
2Institute of Geosciences, University of Tu¨ bingen, Sigwartstrasse 10, 72076 Tu¨ bingen, Germany
3Lamont-Doherty Earth Observatory, 61 Route 9W – PO Box 1000, Palisades, New York 10964-8000, USA
4Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
*e-mail: E.Rohling@noc.soton.ac.uk; christoph.hemleben@uni-tuebingen.de
Published online: 16 December 2007;
The last interglacial period, Marine Isotope Stage (MIS) 5e, was
characterized by global mean surface temperatures that were
at least 2 C warmer than present1. Mean sea level stood 4–6m
higher than modern sea level2–13, with an important contribution
from a reduction of the Greenland ice sheet1,14. Although some
fossil reef data indicate sea-level fluctuations of up to 10m
around the mean3–9,11, so far it has not been possible to constrain
the duration and rates of change of these shorter-termvariations.
Here, we use a combination of a continuous high-resolution sealevel
record, based on the stable oxygen isotopes of planktonic
foraminifera from the central Red Sea15–18, and age constraints
from coral data to estimate rates of sea-level change during
MIS-5e.We find average rates of sea-level rise of 1.6mper century.
As global mean temperatures during MIS-5e were comparable
to projections for future climate change under the influence
of anthropogenic greenhouse-gas emissions19,20, these observed
rates of sea-level change inform the ongoing debate about high
versus low rates of sea-level rise in the coming century21,22.
Have you built your Ark yet Luke?
If you had read my linked post Mr T you would have noted that I was fully aware of the claimed volcanic influence on the PIG. In fact, I pointed out that a glacial collapse due to volcanic activity would either need a very major event or a continuous large eruption over many many decades. Both of which are very rare and intermittent.
And this guff about ice melt being non-linear sounds clever to the uninformed but it cuts no mustard here. The polar sun can only melt ice for a small part of the year and if that melt water is on a flat surface it will sit around for a few weeks and then freeze over again.
And this limited capacity to melt ice does make glacial melt rates mostly linear. You cannot get cumulative melting if the stuff freezes over again each winter.
In any event, your attempt to sidestep the key issues with the gross exaggeration of the changes in the PIG is quite transparent. And as all the researchers had previously stated that the situation with the PIG was more pronounced than the rest of the West A glaciers, we can be certain that the debunking of the PIG scarenario has effectively gutted the whole West Antarctic wankfest.
And any claim that the Greenland melt scare has any substance has been trashed by recent significant slowing of glaciers there as well. It is really quite simple, they speed up, they slow down, and only the shonkademics would try to extrapolate from the faster phases.
Your calculations don’t match any of the published measurements. You’re a mile out. But you can find out why yourself. The difference between science and ranting.
The changes in the flow rate of the PIG are continuous with time. The flow changes on PIG and Thwaites are well documented, faster than expected and widespread.
Reality is that sea level has been higher before in the geological past in warmer conditions – gee I wonder how?
And many of the Antarctic glaciers with sea buttresses are showing NET loss. Didn’t say it would be apocalyptic but we seem to have come a long way from “nothing at all is happening”.
P.S. Hard numbers McAdam? – LMAO – well you’re easily bluffed and BTW FO. Baffin – oh that was just for interest on matters cryospheric.
“Rignot says the increased contribution of Antarctica to global sea level rise indicated by the study warrants closer monitoring.”
Load of nonsense. If vast quantities of Ice were sliding into the sea, the sea level would show it. The University of Colorado has a sea level chart for the last 14 years that is showing no acceleration. In fact, it seems to have decelerated in the last couple of years. It’s current rate of increase will give us 13 inches of sea level rise in the next 100 years. Yawn.
http://sealevel.colorado.edu/
Mr T and Luke. Motty has already shown his maths and the references to the base numbers but all you two have done is claim they are wrong without substantiating anything. So how about you treat us all with a scrap of respect and show is your detailed maths and base numbers.
Show us how 100,000Gt of ice can disappear in a few decades when the current discharge rate is only about 3.2Gt? Show us the speed the ice would need to move at near the mouth to comply with your maths. Explain what percentage of ice will need to go before this “tipping point” is reached and why. And show us your calculation for ice deposition as derived from mean precipitation.
Or is your term, “non-linear” just another way of saying “illogical fantasy”?
Tilo – tosh – what have they said the effect would be currently. You only see and think what you want.
John how can you talk about respect after the amount of crass rudeness piled on over time. You really do fancy yourself.
“Respect” in science is not just blundering into a major new field and “ripping in” without gaining some perspective on existing state of existing work and numbers. You’ve got all the tips you’re going to get and Mottsa’s little story is a tribute to the level of the debate.
Face it – this isn’t a science discussion – it’s quasi-political stoush with factoid bluffing. By now one knows not to bother wasting lots of time chasing Mottsa’s flights of fancy or attempt to blur the state of scientific knowledge from a brief newspaper grab. By now you don’t waste any time in rebuttal as you’ll just be shat on regardless. It’s a waste of time once the jaws have closed.
And who says he’s defining the debate parameters anyway?
Best science says there is NET loss of many glacial systems with ocean buttresses. Acceleration appears continuous.
Net continental mass balance is obviously glacial discharge against snowfall.
Sea level have risen in the recent geological past in warmer conditions. Why and how?
So simply one needs some curiosity as to where this might go in what time frame. You’re the guys ranting about apocalypse not me.
I think there are some changes in the cryosphere in both hemispheres worth noting and maintaining a research effort on.
But on the face of ONE press report some of us think that’s carte blanche to ridicule an entire literature and serious group of scientists who have gathered lots of data in very difficult and dangerous conditions. So think about “respect”.
Sorry I meant Alex – Outflow on PIG and Thwaites has increased from 215 Gt/yr in 1996 to 261 Gt/yr in 2006.
Luke “Tilo – tosh – what have they said the effect would be currently. You only see and think what you want.”
Go back to the earlier posts and see stuff like this.
“Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland,
So obviously they are talking about loss that has supposedly already happened and is still happening now.
Concerning lakes under the Ice sheets. We don’t have any historical record to compare to, so we don’t know that they haven’t always been there, and we don’t know what their overall effect will be. What we do know is that there is no great increase in the rate of sea level rise, even though these guys are claiming an increase in ice sheet melt. And we also know that a 75% increase in the rate of the ice sheet melt in 10 years (if it is happening) still adds up to a tiny fraction of the whole and doesn’t effect sea level rise by any significant amount. However, throwing such numbers around is sure to increase their research budget even faster than the ice melt.
I have been hiking in the Rockies in the summer in places where pockets of old packed snow and ice are hanging on the side of some very steep mountains. Some of these are a couple of hundred acres in size. Streams of water are running out from under these things as they slowly melt off at temperatures that get about 50F higher than anything the Antarctic will see. And yet they do not slide down the side of those steep mountains. The unevenness and contours where they sit keeps them well anchored. I think the idea that ice sheets in the interior of the Antarctic are somehow going to go bobsledding to the sea is one of the most absurd ideas that I have ever heard.
“Sea level have risen in the recent geological past in warmer conditions. Why and how?”
They have risen since the last ice age. It’s what they do.
For heavens sake – who says it’s had a major effect on sea level at this point? It’s in the millimetres area which is what is published so stop being a disingenuous suggesting they’re bullshitting their published numbers for funding.
If you wanted to get rich you wouldn’t be doing this bloody hard work for a living. Try to distinguish between newspaper grabs and scientific papers eh?
Who’s talking about lakes under ice or ice sheet melt. We’re talking about glacial discharge – where bloody ice falls off into the ocean – at least get on the page. You’re a mile off the bloody subject mate.
They have measured by ground survey and satellites that glacial output is speeding up because the bloody front of the glacier is being affected by warming seas. There is less buttressing going on.
And we’re talking about coastal glaciers that discharge into the ocean (ongoing for millenia) not the interior of Antarctica.
So we now know you’re a ninny that doesn’t even read what the debate is about in this case. Have you been to school?
Now this is only part of the issue – you have work out the net balance for the whole continent including snowfall – hard task – but it seems to have gone negative.
Sea level has been higher in the geological past when it has been warmer than today. Read latest research above. One might ponder why.
“They have risen since the last ice age. It’s what they do.” well hookey do – the science comment of the year. What an intelligent answer. So shit “just happens” eh? Lordy me.
“So shit “just happens” eh? Lordy me.”
Yeah, I know how you anal types would love to think that you can control everything, but when it comes to weather and climate – shit happens that doesn’t require your permission – Lordy you.
“Try to distinguish between newspaper grabs and scientific papers eh?”
That used to be easy. But now the scientific papers read just like the tabloids.
“Who’s talking about lakes under ice or ice sheet melt.”
You did microbrain. Or don’t you even read your own links.
http://www.sciam.com/article.cfm?id=the-unquiet-ice&page=5
“Abundant liquid water newly discovered underneath the world’s great ice sheets could intensify the destabilizing effects of global warming on the sheets. Then, even without melting, the sheets may slide into the sea and raise sea level catastrophically”
Interesting link Tilo so I googled more on Bell and went back to this 2005 article
“We present evidence for melting at the base of the ice that overlies Lake Concordia, an 800 km2 subglacial lake near Dome Concordia, East Antarctica, via a combination of glaciohydraulic melting (associated with the tilted ice ceiling and its influence on lake circulation/melting temperature) and melting by extreme strain heating (where the ice sheet is grounded). An influx of water is necessary to provide nutrients, material and biota to support subglacial lake ecosystems but has not been detected previously. Freezing is the dominant observed basal process at over 60% of the surface area above the lake. The total volume of accreted ice above the lake surface is estimated as 50-60 km3, roughly 25-30% of the 200 ± 40 km3 estimated lake volume. Estimated rates of melting and freezing are very similar, ±2-6 mm a−1. The apparent net freezing may reflect the present-day response of Lake Concordia to cooling associated with the Last Glacial Maximum, or a large influx of water either via a subglacial hydrological system or from additional melting of the ice sheet. Lake Concordia is an excellent candidate for subglacial exploration given active basal processes, proximity to the Dome Concordia ice core and traverse resupply route”.
http://nora.nerc.ac.uk/2023/
As I said, the ice melt story goes on.
IMO increased exposure to the latest science will wake a few more sleepers
Anyone thinking about under sheet friction?
Good grief Tilo. There are a variety of mechanisms depending on where you are on the planet. If you had noticed we had been discussing the Pine Island Glacier. Try to keep up.
“But now the scientific papers read just like the tabloids.” – so tell us then Tilo, what journal papers from what journals have you read of late that would draw you to that conclusion? Just a few will do.
“Interesting link Tilo ”
It was Luke’s link. Provided earlier in the discussion. You would think that he would have read it.
“As I said, the ice melt story goes on.”
Yes, and it has gone on since the ending of the last ice age.
“IMO increased exposure to the latest science will wake a few more sleepers”
I don’t know why. The story is enough to put me to sleep. Just because some people have found some water under ice sheets doesn’t mean that it hasn’t always been there. In any case, the only significance that it all has is in terms of sea level rise. And that is currently 13 inches per century and showing no further acceleration.
“what journal papers from what journals have you read of late that would draw you to that conclusion?”
Any of Michael Mann and the Hockey team’s temperature reconstructions will do. The idea that you can create temperature reconstructions using proxies that contain virtually no temperature data because they are moisture limited – and then alarm the world by declaring “unprecedented temperature rise” is comic stuff made stricty for the tabloids and for the people awarding study grants. Hansen’s warning of a 25 meter sea level rise in front of government committees is more tabloid stuff. He is trying to scare the children of the world with warnings of 82 feet of sea level rise when the IPCC only predicts about 19 inches over the next 100 years and when the University of Colorado shows a trend of only 13 inches.
Fortunately, there are a few well done pieces of science out there still. For example, Linah Ababneh’s recent tree ring series. Her objective wasn’t to create evidence for making a political statement, but simply to learn if there is a difference between growth patterns of strip bark bristlecone and foxtail trees and non strip bark samples of the same tree. She took samples from the same kind of trees and in exactly the same area as the trees that were used by Mann and the hockey team for their proxies. Of course Mann didn’t collect the earlier series. Two men by the name of Graybill and Idso did. Their objective in collecting the samples was to demonstrate the effect of CO2 fertilization on the trees.
Graybill and Idso seemed to have found their effect, but with the help of a little cherry picking. They sampled 48 trees, but only archived 17 of them. And the trees that they archived seemed to be exclusively of the strip bark kind. They did, indeed, show some 20th century acceleration of growth.
Ababneh’s series included 100 trees, and she sampled both strip bark and non strip bark trees. When the trees were sorted by type, the strip bark trees showed an acceleration in their growth rings after stripping. The non strip bark trees showed only a tiny amount of growth in the twentieth century for both CO2 fertilization and for increase in temperature combined. In any case, they definitely could not serve as proxies for currently observed temperature increases, so how could they serve as proxies for temperature increases that would have occured in the Medieval Warming Period.
Graybill was able to get a bit of a hockey stick effect by cherry picking certain strip bark trees. But of course most of those trees were probably not strip bark 1000 years ago, so they showed nothing but flat temperature up to the last century.
Mann, being the political opportunist that he is, decided that Graybills series was just what he needed, even though Graybill had no intention of creating a temperature sensitive series. Mann liked Graybills results so much that he weighed the series higher than any other. In fact, the Bistlecone series was weighed 290 times as high as his least heavily weighted series.
Now, thanks to Linah Ababneh’s apolitical and well done doctoral dissertation, we know that bristlecone pines and foxtails contain virtually no temperature information. They live in places that are typically very dry and they are primarily moisture limited.
So, what do we know. We know that not only did Mann make numerous mistakes in his calculations, but his primary source of data was pure trash. Mann’s students and fellow collaborators used the same Graybill series to produce the same worthless temperature reconstructions themselves. From these sources we get the “twentieth century temperature rises that are unprecedented in the last 1000 years” claims. And they are completely fraudulent.
Yes yes all very fascinating but what actual papers have you read of late, not a parroting of blog site bilge.
What papers again were they Tilo?
Mann is quite old news now.
No journal papers is the answer isn’t it.
You’re just having a little ranty rant like most of you dudes do.
Off to climateaudit with you for another roll in the pig slops.
“not a parroting of blog site bilge.”
You mean the kind of stuff that you post here?
“Mann is quite old news now.”
Only because you are out of touch. The destruction of his and the hockey teams data set has only happened in the past year.
What papers again were they Tilo?
This one.
http://www.springerlink.com/content/8j71453650116753/?p=fcd6adbe04ff4cc29b7131b5184282eb&pi=0
This one.
http://www.geo.arizona.edu/Antevs/Theses/AbabnehDissertation.pdf
This one.
http://www.ncasi.org/Publications/Detail.aspx?id=3025
This one.
http://www.ecd.bnl.gov/steve/pubs/HeatCapacity.pdf
But all that really doesn’t matter does it Luke. You are just plain too dumb to deal with the material that I presented in my post so you are seeking a distraction to get your mind off the fact that you cannot answer any of the things that I brought up.
Off to realclimate with you to get your pablum from the high priests.
“The last interglacial period, Marine Isotope Stage (MIS) 5e, was characterized by global mean surface temperatures that were at least 2 C warmer than present1.”
At least he said “at least”. Of course they could have been 5C warmer, in which case the basis for comparison is dubious. What are his error bands on the temperature estimate? Considering how difficult it has been to create a temperature reconstruction for the last 1000 years, I have to believe that one for 120,000 years ago would be very difficult and would contain some huge error bands.
Next question is, how can he be so certain about the attribution of that temp increase?
And lastly, why would he use observations from 120,000 years ago when the holocene optimum was warmer than today for a couple of hundred years so that he could check his theories about sea level rise against a much more recent period?
Tilo – don’t try to bluff with a quick Google.
Springerlink gives it away mate – do you think we’re that gullible.
You’re not reading the literature seriously just parroting what Climate cesspit has linked and selectively summarised for you. Wake up !
Or you could just quote the last few lines of the conclusion text from the Torneträsk tree-ring paper.
If you’re so interested in the MIS paper well read it and have your questions answered. You’re obviously well used to this sort of thing (Not!).
And Tilo – what is the point of answering your irrelevant questions on the wrong take on the subject. You’re clearly not on the page even.
“Springerlink gives it away mate – do you think we’re that gullible.”
You are an AGW cultist. They don’t come any more gullible than that. I suppose you would deny that I read the papers if you saw me reading them. So there is no point to this silly game. For that matter, I could couldn’t give a rats ass what you believe anyway.
“what is the point of answering your irrelevant questions on the wrong take on the subject.”
I’m willing to bet that you are too dumb to explain why it is the wrong take on the subject. You are paralyzed with fear at going near the subject because you know that when it’s all over you will be exposed as a fool. But you need have no fear of that Luke – because everyone knows it already. My guess is that you’ve trotted over to realclimate or to Tamino to see if they can give you some flimsy excuse for the Ababneh data, but they can’t, so you don’t have the courage to tackle the subject.
Well it’s probably better than being a tetchy little denialist drongo.
Don’t bother creating a diversion – you’ve been caught out bulldusting. Yes …..
Tilo: “I don’t know why. Just because some people have found some water under ice sheets doesn’t mean that it hasn’t always been there” etc –
I notice you used the “cultist” word re AGW and I presume Luke. Let’s examine some points of faith, both yours and mine hey. Can you trust your surgeon and his operating team as they put you under like I can?
Over the years I had to work in support of many professions, engineers, geologists, scientists, law and order etc. At what point do we concede somebody else knows a thing or two more than “I”? We don’t have to depend on others doing the science but it helps if we know what to expect.
About fifty years ago I noticed there were great differences between ice cap and glacial remains. One place was littered with shallow lakes while others around were pocketed with a few very deep lakes and that was quite a while after I first learned about the inland coastlines. Local knowledge helps us understand the land and sea. In those days I was simply seeking lost Stone Age tools and their origins. I can say as a mug amateur, ice age trends have impacted on our domestic and social behavior for at least 40.000 years.
As a retired professional in measurements and standards, lets suggest the current rates of change in our environment are unprecedented in modern times.
Gavin – your interest in plumbing and under sheet friction is indeed timely.
Nature Geoscience 1, 33 – 37 (2008)
Response of glacier basal motion to transient water storage
Timothy C. Bartholomaus1,2, Robert S. Anderson1,2 & Suzanne P. Anderson1,3
Abstract
Basal motion of glaciers is responsible for short-term variations in glacier velocity1, 2, 3, 4, 5, 6. At the calving fronts of marine-terminating outlet glaciers, accelerated basal motion has led to increased ice discharge and thus is tightly connected to sea level rise1, 7. Subglacial water passes through dynamic conduits that are fed by distributed linked cavities at the bed, and plays a critical role in setting basal motion8. However, neither measured subglacial water pressure nor the volume of water in storage can fully explain basal motion2, 3, 4, 5, 6, 8, 9. Here, we use global positioning system observations to document basal motion during highly variable inputs of water from diurnal and seasonal melt, and from an outburst flood at Kennicott Glacier, Alaska. We find that glacier velocity increases when englacial and subglacial water storage is increasing. We suggest that whenever water inputs exceed the ability of the existing conduits to transmit water, the conduits pressurize and drive water back into the areally extensive linked cavity system. This in turn promotes basal motion. Sustained high melt rates do not imply continued rapid basal motion, however, because the subglacial conduit system evolves to greater efficiency. Large pulses of water to the bed can overwhelm the subglacial hydrologic network and incite basal motion, potentially explaining recent accelerations of the Greenland Ice Sheet3, where rapid drainage of large surficial melt ponds delivers water through cold ice10.
So it’s the disturbances that upset the plumbing. Change is the issue.
Natural lulls of meltwater delivery to the bed of an ice sheet should almost ensure that subsequent high meltwater inputs will encounter a constricted flow system and hence incite basal motion; conversely, if melt delivery is steady or slowly changing, the conduit system can adjust and basal motion may not be induced17. As we have shown in the outburst flood at Kennicott, discrete pulsed water inputs generate the strongest transients in the subglacial water system and promote the strongest basal-motion response. If increased melt on Greenland30 results in greater frequencies, durations or magnitudes of pulsed water delivery to the bed10, the glacier should respond with more enhanced basal-motion events, and hence greater mean rates of ice discharge towards the sea.
Luke: A few thoughts on ice at the margins
Altitude and terrain determine particular ice formations. Given permanent snows on hard steep slopes tend to churn ice in the valleys (circ cutting), static ice blocks must have a melt zone below that develops into pools based on crust temperature of the major land mass. Although elevated terrain can maintain solid caps during glacial decline those caps must be virtually floating on fully covered lakes of melt water. Cap movement including additional snows can only add to the heat at the base generated from friction at all the binding points including those remaining at the cap’s edge.
IMHO icecap breakdown is initiated by warming seas and landmass, not volcanoes and the theme supposed here. My reasons? Primarily an association with various ice age remnants in seasonal snow fields at altitudes 4,000 ft above a rift valley. Nearby volcanic plugs suggest a long history of sleepiness.
“As a retired professional in measurements and standards, lets suggest the current rates of change in our environment are unprecedented in modern times.”
You may suggest it if you like. But I will only accept it when there is evidence. Currently the strongest evidence is that the changes are not that unusual.
Concerning the rest of your post, I’m not sure that I understand it. If you are saying that there is ice melt or glacier melt, my response would be that there has been since the last ice age. If you are saying that it has accelerated, I would agree that it has done so, at least in the short run. If you are saying that this is a serious problem, I completely disagree with you. We are still only going to get 13 inches per century if you look at the University of Colorado study and 19 if you like the IPCCs exaggerations. These fantastic multi-meter scenarios are designed to frighten children and the gullible, and they are unworthy of anyone who wishes to call themself a scientist.
“So it’s the disturbances that upset the plumbing. Change is the issue.”
I can accept their reasoning on this. However, global warming as a source of change would simply increase the size of the plumbing. You would have to have more radical swings in the seasons – warmer summers combined with colder winters – to have this effect continue.
So, no sign of Mr T and his maths. And what a breathtaking cop-out from Luke, even by his low standards.
Where did you get the “Outflow on PIG and Thwaites has increased from 215 Gt/yr in 1996 to 261 Gt/yr in 2006” numbers Luke?
The link in my post to Shepherd et al http://www.spri.cam.ac.uk/research/projects/pineislandglacier/figures.html#figure4
Shows the 2001 map of the PIG and outlines the boundary of the portion that is moving at 200m/year. It also includeds a scale that makes it clear the cross section is 30km and the other link to Bindschadler, http://antarcticsun.usap.gov/science/contenthandler.cfm?id=1277 makes it clear that the ice is only 500m thick at the grounding line.
“The site is about 35 kilometers from the calving edge of the 800-square-kilometer ice shelf. That’s close to where they expect to find the grounding line, where the warm dense ocean water hits the ice in contact with the bedrock.” and went on to say, “If all goes as planned, work would begin in earnest the next two field seasons to use a hot water drill to bore through the 500-meter-thick ice and lower instruments into the ocean cavity below.”
So 30km x 0.2km x 0.5km = 3km3 (3Gt) annual flow. So where did Luke get his 215 – 261Gt?
http://www.smh.com.au/news/national/the-myth-of-the-noble-scientist/2008/03/02/1204402275168.html For you lot camping out,in case it snuck under your radar.
Well against every bone in my body, as I know you’ll immediately back up the fully loaded manure truck, I could send you what I have and some more if you asked politely. Won’t have enough detail for you I suspect. And of course outflow isn’t nett either. You could of course then do the right thing, before putting the boot in, and do a “Keeling” and email the lead author who might (even though being a climatoid scumbag lefty hell-bent on scaring the willies out of western civilisation) know a few things.
No, Luke, spare us all the defamatory guff, and tell us ALL where you got the numbers from. And no photocopies of your backside, now.
You came out swinging and sneering about non-linear maths rendering my calculations wrong but neglected to point out that linear equations are routinely compared with the non-linear by way of relevance testing.
So most village idiots would be able to understand that a (linear) calculation using this year’s discharge from a large ice mass which resulted in a total of 58,476 years to disappear is unlikely to be absolutely correct due to the number of variables at play. These variables obviously mean we are dealing with a non-linear equation but that is absolutely no excuse for using non-linearity to justify a complete collapse in “a few decades”.
A proper approach would be to run a number of calculations with differing key variables to obtain a range of outcomes that would vary around the result obtained by a lineal equation. That is, one might say 50,000 years, another 40,000 years while another could just as easily indicate 70,000 years or never.
The lineal calculation gets us into the general “ball park” while a range of non-lineal calculations can, if conducted by people with an interest in approaching the truth, clarify the degree of potential variance.
So spare us all the smoke and mirrors.
“and email the lead author who might know a few things.”
What’s the point? Sea level is rising 13 inches per century. If you are going to get 13 inches per century, something has to be melting. The big question is “so what”? The sea level rise reflects the imbalance between moisture falling on the continent and ice dumping into the sea. If the changes that occur with this glacier don’t reflect in an acceleration of sea level rise, then it is irrelevant. Looking at the University of Colorado sea level chart, there is no acceleration. If anything it has lately shown deceleration. The BBCs “Surge to the Ocean” is not impressing the ocean.
Tilo: What book are you reading?
“In the last 30 years, the financial hub of Shanghai has seen the sea level rise 115 mm, or the length of half a chopstick, the report says.
Tianjin, a major port about two hours’ drive from Beijing, has seen the level rise as much as 196 mm, about the length of a new pencil.
In the past 30 years, the country’s overall sea level has risen 90 mm with the average offshore surface temperature going up by 0.9C”
http://www.chinadaily.com.cn/china/2008-01/16/content_6396575.htm
The financial hub of Shanghai has had an unprecedented volume of concrete and steel placed upon it over the past 30 years. This, combined with the almost complete surface seal that removes any moisture percolation from above, makes it an ideal candidate for subsidence. Ditto Tanjin.
Meanwhile Sydney’s Fort Denison has recorded minimal change over the past 60 years. Ditto Brisbane.
Still no word from Luke on his fanciful claims of PIG ice discharge.
Well he didn’t ask nicely did he. Off to the library.