Wilkins Ice Shelf Collapse

GIVEN it is still really cold at the Antarctic, is it really very scientific to blame global warming for the likely collapse of the Wilkins Ice Shelf? How good is the evidence supporting this hypothesis as the possible cause of the possible shelf collapse, as opposed to say ice growth generating internal stress or undersea volcanic activity?

140 Responses to Wilkins Ice Shelf Collapse

  1. J.Hansford April 7, 2009 at 11:09 am #

    This is rubbish…. atmospheric temp at the location of the Wilkins ice shelf cannot melt nor cause this huge mass of ice to melt.

    Ice shelves are attached to Glaciers, Glaciers move…. Ice floating on water melts from the bottom up, slowly…. eventually everything becomes unstable….. Atmospheric temperatures of the amount we are talking about and in the 60 or 80 year time span that they are supposedly have had an effect for…. Couldn’t possibly cause the Wilkins ice shelf to melt.

    There is such garbage science in all of this.

    Tell me this. Does snow fall build up on top of the ice shelf?….. Does the bottom of the ice shelf slowly melt, stay the same or does it accumulate ice? Does the Ice shelf get pushed further into the sea by the Antarctic Glacier?

  2. slim April 7, 2009 at 11:31 am #

    “Given that it is still really cold…”

    Case closed. Oh dear.

  3. janama April 7, 2009 at 12:39 pm #

    I agree – this is bullshit.

    I’ve been following remarks made by Dr David Vaughan from BAS (British Antarctic Survey) and he avoids the global warming question as best he can – Last year in January he was saying it was a huge volcano that they’d discovered during their 90 day stay on the ice shelf that he believed it was still active.

    http://www.nature.com/ngeo/journal/v1/n2/abs/ngeo106.html

    Today he’s saying “well it could be global warming”, “it might be” avoiding saying explicitly that it is AGW. This is only happening on the peninsula which accounts for 1% of antarctica – the rest is stable. There are also other active volcanoes in the area, Mt Erebus, Deception Island, South Sandwich Islands are all still active.

    Plus the land formations of the west antarctic are different to the east

    http://www.eurekalert.org/pub_releases/2009-03/ps-wai031709.php

  4. Luke April 7, 2009 at 12:57 pm #

    Look at ’em go – of course the denial-o-sphere would deny it. What other alternative is there. Just overlook or deny all the research.

    “Nothing to see here – move along …”

    Volcanism – what a joke !

  5. dhmo April 7, 2009 at 1:33 pm #

    The sea ice extent has only been collected since 1979. Looking at this record our worry might be it is increasing rather than contracting. See http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.south.jpg it is 1 million square kilometres bigger than the mean of 1979-2000. Also note that at the moment it is expanding at the rate of 2 million square kilometres a month!

    There is also a brilliant picture at http://nsidc.org/data/thermap/antarctic_10m_temps/dixon_map.html of the temperature map. Wilkins is on that thin wispy bit to the far left where it is suffering a heat wave of 7.6 degrees.

    To get alarmed by this collapse when the sea ice around Antarctica fluctuates by 13 million square kilometres per annum seems to be remarkably stupid or ignorant. We need these collapses if it didn’t we should be contemplating the next ice age.

  6. Lank April 7, 2009 at 1:37 pm #

    Breaking news (excuse the pun) – The BAS “scientists” have announced that the Wilkins Ice Shelf in the Antarctic is on the verge of ‘collapsing’.
    But haven’t we heard this before ….. this is exactly what they said last year except last year the Wilkins Ice Shelf was the size of the Isle of Man and this year it’s the size of Wales. That’s a lot of ice growth considering that global warming is supposed to be melting all the ice. The BAS (British Government funded) fail to explain how the Wilkins Ice Shelf can collapse in 1998 and again in 2008 and again in 2009……..

  7. janama April 7, 2009 at 1:38 pm #

    Just overlook or deny all the research.

    oh really Luke – Dr Vaughan is NOT a researcher? please fill me in as to what he is.

    and Pollard and Robert M. DeConto, professor of climatology, U. Mass, report their findings in today’s (Mar. 19) issue of Nature. – just a couple of amateurs eh?

    you are the joke maate!

  8. Ian Mott April 7, 2009 at 1:40 pm #

    Ice sheets calve. Get used to it.

    The reason they calve is that annual precipitation on the Antarctic coast is over 200mm or 2 metres per decade, or ten metres every half century. If the ice sheet was not attached to land based ice, and water temperatures remained below zero C, then the floating sheet would drop by 9 metres every half century as the total ice mass adjusts equilibrium in water.

    But when the ice sheet is attached to land ice it cannot adjust it’s mass in the water (sink) without severing the attachment to the land ice. Ten metres of ice weighs 9 tonnes per square metre, 90,000 tonnes per hectare and 9 million tonnnes per square km. And that makes for an absolute $hit load of weight to be defying gravity with.

    And the wider the ice sheet is, the more powerful the leverage becomes at the interface between land ice and shelf ice.

    Ocean temperatures for this area in March 2009 were zero C. If the break had taken place in January there may have been a slim case but SH temperatures have declined over the past decade to a greater extent than NH temps.

    HOW CAN IT BE CAUSED BY GLOBAL WARMING WHEN THERE HAS BEEN NO WARMING?

  9. spangled drongo April 7, 2009 at 2:13 pm #

    Who are the real deniers here?

    14,000 km2 comes adrift yet there is 50 times more than that in above average sea ice in the Antarctic.

    Could it be for other reasons possibly?

    Well, er, yes, but who wants to know about that.

    Is this the area where Steig et al got all the data to show the overall warming by any chance?

  10. SJT April 7, 2009 at 3:04 pm #

    Underwater volcanoes? How about Aliens? Has no one considered Aliens? I’d like to know why not? If we are serious about this science, surely we have to look at all the alternatives? What sort of scientists are these people? Are they still beating their wives?

  11. janama April 7, 2009 at 3:11 pm #

    SJT –

    A recent volcanic eruption beneath the West Antarctic ice sheet
    Hugh F. J. Corr & David G. Vaughan

    Indirect evidence suggests that volcanic activity occurring beneath the West Antarctic ice sheet influences ice flow and sheet stability1

    peer reviewed, published in Nature.

    http://www.nature.com/ngeo/journal/v1/n2/abs/ngeo106.html

    what more do you want!

  12. Neville April 7, 2009 at 3:58 pm #

    To say that this is the result of global warming is beyond stupid and unfortunately falls into the fundamentalist religious camp which is accepted gleefully by the usual adherents infesting this blog.
    What we can say with certainty is that Antarctica as a whole is gaining ice not losing it and certainly this break will not raise sea level at all. ( ABC radio World Today 6-4-09. )
    What a beautiful video, BTW I would love to know the scale and height of that ice wall above sea level as you look down the channel formed by this incredible natural act.

  13. Gordon Robertson April 7, 2009 at 4:32 pm #

    The Wilkins and Larsen ice Shelves are on the Antarctic Peninsula. Duncan Wingham, Professor of Climate Physics at University College London, and an expert on Antarctica, claimed a while back that all the research is being done there because it’s a lot milder than it is on the continent. In other, words, we have a load of sissies being shocked by what ice tends to do, break up.

    The oceans down there are some of the roughest in the world. Any sailor fears the water off South America and the northern tip of the Peninsula is only 600 miles from South America. Here’s an article featuring Duncan Wingham:

    http://www.theregister.co.uk/2005/02/24/ice_shelf_collapse/

  14. James Mayeau April 7, 2009 at 4:32 pm #

    So squared off and uniform. I never saw an icecube melt that way. They usually go a bit squidgy, and rounded off at the margin. Like this one.
    http://www.antarctic-diary.co.uk/Photos/f-022%20Icebergjpg.html
    or this one.
    http://www.mrtech.com/photos/random/Iceberg.jpg.html

  15. janama April 7, 2009 at 4:35 pm #

    To say that this is the result of global warming is beyond stupid and unfortunately falls into the fundamentalist religious camp which is accepted gleefully by the usual adherents infesting this blog

    It’s actually having flow on effects worldwide. The warmists have been crying wolf for so long now that when a wolf appears no one wants to know about it – that’s what has recently occured in Italy where a scientist was trying to warn of the impending earthquake and was told to STFU.

  16. wes george April 7, 2009 at 4:52 pm #

    It’s astounding! SJT is right. We must be in a Time Warp. If we are going to consider Anthropocentric Global Warming as the cause, then we might as well consider the case for Extraterrestrial intervention…Rock on.

    It’s so dreamy. Drake’s equation’s almost mathematically guarantees that alien civilizations must exist, which is far more than we can say for the tenuous logic of the AGW hypothesis. It’s another dimension.

    If they aren’t under sedation it would be cool to hear acolytes Slimy, Wille E. Luke, and Sjt explain the physics of ice transmogrification into transwhatever at yearly average temps of -45. That is, if it isn’t a secret that can’t be exposed to scrutiny by the uninitiated. (I promise I won’t tell. Wink, wink…)

    Of course, if Midnight Oil’s lead singer says AGW is the cause, it must be so. Nothing can ever be the same. Welcome to the Rocky Horror Picture Show World of Scientific Method….

    ….just a jump to the Left!

    So come up to the lab… I see you shiver with anticipation…

    http://www.youtube.com/watch?v=xWXoFAaZ11M

  17. Nick Stokes April 7, 2009 at 5:51 pm #

    Here’s Dr David Vaughan quoted in the Australian today:

    Professor Vaughan said that warmer conditions in the Antarctic Peninsula had caused the ice bridge to melt and that it was likely to be linked to global warming. Temperatures in the peninsula have risen 3C in 50 years.

  18. janama April 7, 2009 at 6:15 pm #

    “likely to be linked” – why not IS linked?

  19. wes george April 7, 2009 at 6:29 pm #

    “Temperatures in the peninsula have risen 3C in 50 years.”

    Therefore, the only explanation is clear: Alien Intervention.

    Oh, dear.

  20. janama April 7, 2009 at 6:37 pm #

    or local weather.

    http://users.tpg.com.au/johnsay1/Stuff/ant_temp.jpg

  21. Lee Kington April 7, 2009 at 7:15 pm #

    It is my feeling that the ice shelves do not indicate current or recent conditions, but rather, an accumulation of various effects over time. During the LIA they were exposed to SST’s which were much cooler.

    The record indicates that, from 1701 to 1761, surface temperatures were on average 1.4°C cooler than during the past 30 years. ( Source: http://cat.inist.fr/?aModele=afficheN&cpsidt=1132291 )

    At other times the oceans in the area have been much warmer (Holocene Climate Maximum, Roman Warm Period, Medieval Warm Period, etc). Yes, some of the Ice lost has been tens of thousands of years old. However, 40,000 years ago their reach over the ocean was most likely much further. A lot has changed in the past 10,000 years, the warming into the Holocene. That warming and 10,000 years of the interglacial, 10,000 years of temps 8 degrees warmer than when they formed, 10,000 years of warmer seas beating on them is what the break-off’s reflect.

    To some extent, ice shelves are a poor climate indicator, they react to slowly. The story they tell is at times the same story that Glaciers which do not have a coastal edge tell. I did a brief blog on The Story of Glaciers not long ago.
    http://penoflight.com/climatebuzz/?p=88

  22. cinders April 7, 2009 at 8:16 pm #

    Anyone notice the date of the you tube video at the start of this thread.
    I thought I was watching the same vision as on tonight’s news, yet from the 2008 date of the ‘you tube’ video, this appears to be file footage.
    Surely this is not just a publicity gimmick to pressure delegates at the 32nd Antarctic Treaty Consultative Meeting that commenced 6 April (US time)!
    Or perhaps the world’s TV stations didn’t think the European Space Agency photo was dramatic enough. see http://www.esa.int/esaEO/SEMWZS5DHNF_index_0.html

  23. Lazlo April 7, 2009 at 8:31 pm #

    Well SJT and Luke are proving they are real thickos on this one – deriding the notion of undersea vents indeed. Hey, perhaps they are in denial about tectonics.

  24. Luke April 7, 2009 at 9:19 pm #

    You’d have to be a moron to think that Wilkins is melting due to volcanism. Typical denial-o-sphere bilge. Not one scintilla of evidence of volcanism being involved.

    NONE !

    As for Pollard and Robert M. DeConto, – well Janama mate – did you read the paper – of course not ! So don’t bluff.

    “Even so, the modelling by Pollard and DeConto3 may already be robust enough to attempt to put initial constraints on the amount of nearby ocean warming required to generate enough sub-ice-shelf melting to initiate a significant retreat of the West Antarctic ice sheet. The required ocean warmings, of the order of 5 °C, may well take several centuries to develop. But such an outcome could result from the accumulation of total greenhouse-gas emissions projected for the twenty-first century, if emissions are not greatly reduced1. The implied transition time for a total collapse of the West Antarctic ice sheet of one thousand to several thousand years3 seems rapid by Antarctic standards. But it is nowhere near the century timescales for West Antarctic ice-sheet decay based on simple marine ice-sheet models10.”

    As for Corr and Vaughn – over 200 years ago – LOLZ !!!

    Come on guys give it away.

    If you want to have a serious go tell me it’s a natural cycle….

    Is it AGW – who knows – but it’s the sort of stuff you’d expect isn’t it.

    The new denial-o-sphere approach is to react to a loaded gun in the face by saying “bullshit – that’s not a gun – and if it is – it’s irrelevant”.

    Predictable that Jen would run Wilkins – coz it’s heap big bad medicine for the denialists.

    YOU MUST DENY IT ! You have to. It’s staring you in the face?

    Denialist scum – nah nah nah nah – na naa – we told ya’s so !

  25. wes george April 7, 2009 at 10:15 pm #

    “If you want to have a serious go tell me it’s a natural cycle….”

    No, No, Luke, Luke, no want serious. Want funny, funny. You want?

    Willie E. Luke is self-destruct like a N. Korean satellite. Spectacular, but impotent. funny, funny. Like Coyote.

    http://www.youtube.com/watch?v=hz65AOjabtM&feature=related

  26. Louis Hissink April 7, 2009 at 11:04 pm #

    Slim:

    ““Given that it is still really cold…”

    Case closed. Oh dear.”

    Some statistics:
    Coldest temp july 21, 1983, -89 degrees Celsius, Vostok station.
    Warmest Temp Jan 5, 1974, +15 degreesCelsius, Vanda Station.

    Mean Temps – Winter -40 to -70 degrees Celsius
    Mean Temps – Summer -15 to -35 degrees Celsius

    Source: http://www.antarcticconnection.com/antarctic/weather/index.shtml

    Apart from 1974, ice melting below 0 degrees Celsius requires the adminstration of some stupid drug, or other mind bending stimulant such as Lysenkoist tea.

  27. Louis Hissink April 7, 2009 at 11:22 pm #

    Luke:

    “Even so, the modelling by Pollard and DeConto3 may already…”

    Heaven’s sake, how about getting back to physical reality.

  28. Fred from Canuckistan . . . April 8, 2009 at 4:56 am #

    1. Ice mass in the center of Antarctica is increasing and is about 10,000 ft thick.

    2. Water/Ice flows downhill towards sea level.

    3. When the slowly moving glaciers reach the ocean they push out over the water and float.

    4. Eventually the floating ice sheet cantilevers itself and breaks off.

    5. Happens at any temperature.

  29. Bill Illis April 8, 2009 at 5:09 am #

    The Wilkin’s ice shelf is at 70S, the same relative latitude as the tip of Norway.

    It has to be a really old ice shelf, probably going back to the last ice age, as it is not fed by the interior Antarctic glaciers but by a very small mountain range which is itself on an island and not attached to Antarctica.

    There are some old satellite pictures going back to 1989 here.

    ftp://sidads.colorado.edu/pub/DATASETS/ICESHELVES/wilkins/

    This one from 1992 shows that just the edges of it near Charcot island which have eroded. it has probably been going on for 10,000 years.

    ftp://sidads.colorado.edu/pub/DATASETS/ICESHELVES/wilkins/wilkins.920411.temp.jpg

  30. janama April 8, 2009 at 5:56 am #

    Typical denial-o-sphere bilge. Not one scintilla of evidence of volcanism being involved.

    NONE !

    Dr David Vaughan would dissagree with you luke. That’s why he won’t say it’s AGW definitively!

  31. Luke April 8, 2009 at 6:39 am #

    Louis – – WTF – huh – Pollard issue wasn’t mine. It was Janama’s ! And the quote was from their paper. It was about what they supposedly said or did not. Turn off the auto-pilot – engage brain.

    Wes – inane as usual. I’m surprised you’ve been able to restrain yourself from a big rant or giving us a blow by blow precis post. Any independent thoughts? – of course not.

    Janama – come up with a single bit of volcanism evidence. Secondly read all other research information available. Think about balance of probabilities.

  32. Ian Mott April 8, 2009 at 9:44 am #

    The sea surface temperature in March was zeroC. It follows that only the surface temperature could have been warmed during December, January and February. Temperatures below the surface will obviously have been colder. The bottom of the ice shelf is obviously well below the surface where the water temperature is below zero.

    So despite the fact that temperatures in general may have risen by 3C over the past 50 years, the ocean temperatures under the ice sheet remain below freezing and could not have melted the bottom of the ice as a result of climate change.

    Any warming from atmospheric heat would have melted surface ice and hence, would have reduced pressure on the ice sheet to calve by reducing the mass/weight of ice above the water equilibrium point.

    The only causal factor at play is the build up of precipitation/ice on top of the shelf to the point where the required flotation adjustment was more than the interface with land ice could sustain.

    Big deal. So 1000 years of accumulated localised precipitation has been returned to the ocean from whence it came. The Wilkins ice sheet is in the process of playing its small part in preventing sea level decline. Antarctica must shed more than 1000 cubic km of ice each year to balance continental precipitation and prevent sea level decline.

  33. gavin April 8, 2009 at 11:33 am #

    “The bottom of the ice shelf is obviously well below the surface where the water temperature is below zero”

    ???

  34. Nick Stokes April 8, 2009 at 12:25 pm #

    Gavin, “The bottom of the ice shelf is obviously well below the surface where the water temperature is below zero”
    ???

    Good query. A few posts here are missing that this is a floating shelf, and is in equilibrium with the sea water underneath. Any warming of that water will cause melting from the bottom (and cooling will cause freezing). The equilibrium temp is below zero, because of the salt.

    So Fred from Ca and others above who imply that the shelf is fed from land and loses ice only by calving have only part of the story. They lose mass by exchange with the sea, and they gain mass from snowfall, which for this shelf will be more important than glacial flux.

    And for janama, it’s a huge stretch to go from Dr V cautiously expressing likelihood but not certainty about an AGW cause to say that he thinks volcanism is a cause, which he didn’t even mention.

  35. Luke April 8, 2009 at 1:11 pm #

    Nonsense from Motty

    It’s the warmer water alright !

    http://www.theage.com.au/environment/warmer-ocean-led-to-ice-collapse-20081005-4ubw.html

    Aren’t data a bitch?

  36. dhmo April 8, 2009 at 1:29 pm #

    Lets get this straight here is the satellite photo all the fuss is about http://www.esa.int/images/asar200904021_H.jpg note that in the top left hand there is Charcot Island now look at this map of the area http://en.wikipedia.org/wiki/File:Ant-pen_map.png. So the Wilkins Ice shelf is an area bounded by Charcot, Latady and Alexander islands. It is I according to Wikipedia 14000 sq Kms that makes it at about 0.09% of the overall Antarctica sea ice in the middle of winter. Since it is at 70 degrees south that makes it also 2232 from the pole. The satellite shows it is well and truly fractured but by no means gone. It is also clear this is an insignificant change. Whatever the reason I am glad it behaves this way if it didn’t I would be up to my neck in ice here in Canberra in the near future. At the moment the sea ice down there is expanding at about 65000 sq km a day.

    I find the claim that it has warmed there 3 degrees over 50 years an interesting comment that raises other questions which some of you might be able to address. If the Earth has warmed at most .6 degrees in the same period then how? Does warmth follow the activist around? If the sea is 3 degrees warmer and it is caused by AGW then how? If true then it must be significantly cooler elsewhere. Unless you can prove cooling elsewhere then that means it is not AGW. Could it be solely be volcanic activity or something else that delivers the heat where the environmentalist needs it? In Canberra we have a rare lizard that has an instinctive ability to find new development. Once found it inhabits the area so that it is there ready to be threatened. Could the same principle be involved?

  37. janama April 8, 2009 at 1:46 pm #

    And for janama, it’s a huge stretch to go from Dr V cautiously expressing likelihood but not certainty about an AGW cause to say that he thinks volcanism is a cause, which he didn’t even mention.

    I’m sorry BUT Dr Vaughan stated last year in january 2008 that the cause of the ice shelf melt was the still active volcano that they had just discovered. Do a google search for “volcano under wilkins ice shelf, Dr Vaughan”

    That’s why he won’t say it’s AGW!! he believes what he said last year still obviously.

  38. Gordon Robertson April 8, 2009 at 1:55 pm #

    janama ““likely to be linked” – why not IS linked?”

    It’s the new consensus-based science. It’s no longer appropriate to say that a stone dropped from a bridge ‘will’ fall to earth, to be politically correct, one must say the stone is ‘very likely’ to fall to earth. That allows for the likelihood that a small spacecraft will suddenly appear and scoop the stone as it leaves the hand, much like in the Life of Brian, when Brian fell from the temple and we thought he was a goner.

    If we run around making rash claims that something ‘will’ happen, it takes power away from those who think they are in control of nature. Consensus-speak also allows people to make claims that are not true. They use that technique to suck the gullible into accepting what they say, much like the IPCC has sucked millions into accepting their pseudo-science.

    On the other hand, we could all use consensus-speak to enable non-commital behavior and procrastination. When someone asks you out to a do that seems dodgy, you can reply that it’s likely you will be there. When you don’t show up, you have an out. Or you could tell them it’s highly likely you’ll be ill that night, and if you change your mind at the last moment, you can claim you were not as ill as you thought you’d be.

  39. janama April 8, 2009 at 2:05 pm #

    It’s quite likely you are correct Gordon. 🙂

  40. Matthew Slyfield April 8, 2009 at 2:09 pm #

    Looking at the video of the fly over, the edges of the flows along the breaks are nice clean vertical edges. I look at that video and to me it screams mechanical stress, not warming whether from the top or the bottom.

  41. Nick Stokes April 8, 2009 at 2:46 pm #

    Janama I’m sorry BUT Dr Vaughan stated last year in january 2008 that the cause of the ice shelf melt was the still active volcano that they had just discovered.
    You’re not reading carefully. Dr V’s article in the Jan 2008 Nature Geoscience was about a volcano in the Hudson Mountains, at 74.20S 99.25W. This shelf is at 69.45S 75.15W, about 1000km away.

  42. Louis Hissink April 8, 2009 at 3:18 pm #

    Age quote Luke posted

    “The water below the Wilkins was two, three or four degrees above the melting point of sea water,”

    Melting point of sea water?

    Isn’t data interesting.

  43. Ron Pike April 8, 2009 at 4:34 pm #

    To Gordon Robertson.
    Great post, keep it up.
    Pikey.

  44. wes george April 8, 2009 at 5:39 pm #

    AGW propaganda is based upon the mythology of an optimal climate stasis. This is Climate Creationism. The past is better than the future because it isn’t soiled by sinful humanity.

    But the truth is that today is just another day on Earth. There is no “The End Times.”

    http://www.youtube.com/watch?v=Bz9JmpULP3o

  45. sod April 8, 2009 at 5:57 pm #

    You’re not reading carefully. Dr V’s article in the Jan 2008 Nature Geoscience was about a volcano in the Hudson Mountains, at 74.20S 99.25W. This shelf is at 69.45S 75.15W, about 1000km away.

    nice one!

    GIVEN it is still really cold at the Antarctic, is it really very scientific to blame global warming for the likely collapse of the Wilkins Ice Shelf? How good is the evidence supporting this hypothesis as the possible cause of the possible shelf collapse, as opposed to say ice growth generating internal stress or undersea volcanic activity?

    let me see:

    there is MASSIVE evidence of global warming, and of local warming around the Wilkins Ice shelf.

    there is ZERO evidence of undersea volcanoes causing the collapse.

  46. sod April 8, 2009 at 6:02 pm #

    AGW propaganda is based upon the mythology of an optimal climate stasis. This is Climate Creationism. The past is better than the future because it isn’t soiled by sinful humanity.

    this is a completely false claim.

    people with any knowledge of climate prefer as much stability of the climate as possible!
    they know, that climate changes (and especially fast ones) have a massive effect on mankind, and will nearly always lead to war/crisis. (even positive effects can change societies and cause jealousy and creed)

    our assumption is, that natural change is problematic enough. ADDING changes caused by humans (and yes, those changes could ADD UP!) simply is a stupid idea.

  47. janama April 8, 2009 at 6:48 pm #

    nice one!

    yes Sod – Nick made a excellent point which I accept.

    You went on to insist, as Luke does, there is Zero evidence that volcanic activity was responsible and you further said that there was massive evidence of global warming around the Wilkins Ice shelf and the antarctic peninsula.

    I accept there is evidence of SST increasing in the area but I didn’t realise that AGW was site specific and only happens in specific regions.

    The region in question is on the Pacific ring of fire and therefore is a major volcanic area – I have counted 15 active volcanoes within a 1000km radius of the Wilkins ice shelf so I accept that volcanoes must influence SST and thus the breakdown of the ice shelf.

    Could you please point out to me why AGW is so specifically concentrated in this area?

  48. Luke April 8, 2009 at 7:07 pm #

    Actually Janama – maybe it’s an alien nuclear plant under there. One could of course read the literature on these issues for the last few years.

    But hey – you guys HAVE to deny it. You MUST.

    They dragged a temperature probe over a new volcano in the Antarctic Sound – hardly registered.

    And I am absolutely stunned at the denialist committment to uniformitarianism – everything must happen the same everywhere. A radiative forcing change will cause all manner of possible changes in global circulation systems as the world tries to redistribute the heat. Sub-tropics may dry. Some areas may even cool.

    A quick thought experiment – perturb one slightly mild Pacific Ocean with an El Nino event – does the whole world get wetter or drier. Nuh – both happen. Why – changes in global circulation.

  49. david elder April 8, 2009 at 7:13 pm #

    sod says “there is MASSIVE evidence of global warming, and of local warming around the Wilkins Ice shelf.”

    sod, maybe you can help me. For a start I am somewhat underwhelmed by claims of clear-cut strong AGW. Lindzen says there is no statistically significant global temperature rise since 1995. And in World Climate Report Jan. 30, 2009 it is shown that the Antarctic as a whole hasn’t warmed much since the early 1970s.

    But even if I swallow strong AGW – why is the Antarctic Peninsula showing such uniquely high levels of warming? About 5 times the global warming average as I recall. How can we confidently use the Antarctic Peninsula as evidence for human global warming when the amount of warming is so much more than the global average? Isn’t it quite reasonable to at least ask if something else like vulcanism might be involved in the Arctic Peninsula region? Vulcanism sceptics note: there are multiple volcanic sites in this general region of Antarctica, not just one. See Watts Up With That, Jan. 22, 2008.

  50. janama April 8, 2009 at 7:22 pm #

    I wasn’t expecting uniformity, I was explaining why I understood the warming in the area due to increased volcanic activity and let’s face it , we know f@@k all about the volcanic activity in the area let alone how many volcanoes there really are, but being on the Pacific rim of fire you can expect there will be many.

    Yes – I understand that Southern Australia has had a drought but I don’t see any evidence of 2 – 3 degrees difference in temps. The difference in the max temps of Black Saturday were tenths of a degree and we are now all back to normal – whereas in the antarctic this has been going on for years.

  51. Dennis Webb April 8, 2009 at 8:32 pm #

    The folllowing appeared in e-newsletter Crikey.com.au today:

    5. This ice shelf global warming hype leaves me cold

    TUESDAY 7 APRIL 2009

    Ben Sandilands writes:

    Is misreporting really necessary to get the global warming message across to the masses?
    Or is the claimed fate of the Wilkins Ice Shelf simply a case of too good a photo opportunity to pass up, or in this case, pass off, as caused by anthropogenic climate change?
    The news stories are making it sound like the snapping of the last ice bridge between one part of the crumbling shelf and its main body is a portent of doom for a warming planet.
    Only a small part of the Wilkins Ice Shelf is affected by this event. It is also located in the Antarctic Peninsula, which is milder and subject to higher snowfall than the main mass of the continent.
    The mass of ice involved is dwarfed by many larger ice shelf breakouts studied in great detail over the last 60 years in Antarctica.
    It is embarrassing to see scientists and newspapers prostitute themselves in this manner. Are they that desperate to seek inclusion in the politically correct but unscientifically sound association of anything and everything with the truly serious matter of climate change?
    Ice shelves are dynamic. Just as dynamic as they have been for millions of years, during glacials and interglacials.
    For eons before our species industrialised and inadvertently set in train the massive liberation of fossilized carbon that has changed the composition and dynamics of the atmosphere, the oceans and the land, the ice shelves were doing precisely what the Wilkins is doing today, accumulating and shedding ice.
    The same mechanics drive the growth and decay of ice shelves in a range of polar and sub polar environments, some of them verging on temperate maritime climates like that experienced by the Antarctic Peninsula and others in truly brutally cold regimes like those found closer to the poles.
    Ice shelves are extrusions of dense ice formed where glacial flows overrun a coastline.
    When the outflow exceeds the rate at which the glacier can directly fragment into icebergs the glacial mass remains coherent and the surplus pushes outwards into the seas or oceans.
    The natural cycle of an ice shelf is to thicken, broaden and fan outwards, until the stresses of thermal erosion by the sea below, the atmosphere above, the subtle but persistent buckling moment of tidal rising and falling, all combine to fracture and break it into thousands of ice bergs, with the largest known to persist for five or more years while drifting for thousands of kilometres.
    Somewhere in the southern ocean, the bodies of Robert Falcon Scott and his men rest on such a fragment of the Ross Ice Shelf, awaiting the sea burial which was always their lot after dying there in March 1912 on their return from the South Pole, when their last camp was well away from its outermost edge.
    There is no doubting the reality of global warming, nor the ways in which it may affect the rate at which ice shelves form and discharge by increasing or decreasing the accumulation of snow that feeds the vast glacial deltas that flow out into the ice shelves.
    But the Wilkins break up displays the same spectacular process of ice shelf growth and disintegration that has been observed throughout polar exploration.
    Plus a new effect, let’s call it the linear oversimplification of the global warming message regardless of the actual science.
    The sharp fault lines in the Wilkins break up are break points, not melt points. They would have fractured that way regardless of whether the Wilkins environment has warmed (or even cooled) by the few degrees that have been claimed for it.
    There is nothing new either about massive outbreaks of icebergs from ice shelf collapses. In November and early December 2006, for only the second time in 75 years, icebergs were visible on the ocean horizon from high hills near Dunedin, New Zealand.
    The early voyages to Australia reported icebergs in similar latitudes to Tasmania and as far north as close to the Cape of Good Hope, while in 1868, one ship reported a sighting off Cape Leeuwin in Western Australia. In 1894 an iceberg was sighted in the western southern Atlantic in Brazilian latitudes.
    The real science of climate change is very complex but also convincing. Could it be that the seriousness of these issues is being undermined by an unscientific determination in some quarters to convert almost anything that happens in the natural world into an unnatural opportunity to preach a doctrine rather than a science to the general population?
    Tragically for the planet, the Wilkins media event serves to deflect attention from the Rudd Government’s determination to do nothing to diminish the mining of coal which results in the liberation of copious quantities of fossilized carbon which constitutes the overwhelmingly largest cause of the greenhouse gas effect in the lower atmosphere.
    The circus of photo opportunity, glib sanctimonious platitudes and compliant media reporting rolls on.

  52. James Mayeau April 8, 2009 at 9:02 pm #

    But even if I swallow strong AGW – why is the Antarctic Peninsula showing such uniquely high levels of warming? About 5 times the global warming average as I recall. How can we confidently use the Antarctic Peninsula as evidence for human global warming when the amount of warming is so much more than the global average?

    I wonder if it could have something to do with population of climatologists per acre?
    The Pen is thick with them. Possibly the highest condensation of climatologists and assorted greenpeace global warming moa moa’s on God’s green Earth. Like fleas on a dog.

  53. janama April 8, 2009 at 9:34 pm #

    Like fleas on a dog.

    hey – give dogs some credit – the dogs I know wouldn’t stand for such insincerity. 🙂

  54. Bernard April 8, 2009 at 11:11 pm #

    One has to take what is given by the British Antarctic Survey with a pinch of salt especially in the area south of Latin America as the political climate has been warming over the Falkland(Malvinas) Islands recently.

  55. cohenite April 8, 2009 at 11:27 pm #

    luke; that Neville Nicholls piece you kindly sent doesn’t ascribe any AGW factors to drought in SE Australia but describes cause[s] other than El Nino, particularly the intensity of the sub-tropical ridge [STR]. Nicholls pointly excludes the Indian Ocean Dipole from influence, which appears at odds with conventional AGW theory most recently enunciated by Nerilie Abram from her coral proxy studies.

    In respect of this thread I find the preoccupation by AGWers with the NE penninsula extraordinarily blinkered; pro-AGW comments about the alleged temperature history of the NE have been blighted by the recent Steig debacle; in addition to the string of volcanos there is this;

    http://en.wikipedia.org/wiki/File:AntarcticaRockSurface.jpg

    The NE is really a different country to the rest of Antarctica but even so its history of ice level being consistent with AGW is problematic to say the least;

    http://www.agu.org/pubs/crossref/2008/2007GL032529.shtml

  56. Luke April 9, 2009 at 12:30 am #

    Love to respond but spam muncher eats the posts !

  57. Luke April 9, 2009 at 12:32 am #

    http://www.noaanews.noaa.gov/stories2008/images/5-6-08_Overland.pdf

    Read the Antarctic summary in there. Why look further? And why is Patagonia warm too. More volcanoes ? LOL !

  58. Luke April 9, 2009 at 12:37 am #

    On Nicholls paper – well he doesn’t not say it either. But he’s suspicious as you should be. All links to the above. IOD is simply a small but further complication. There’s a more than plausible case for AGW including ozone depletion having moved the entire southern hemisphere circulation around. if you want to open the eyes and do some reading.

  59. bill-tb April 9, 2009 at 2:03 am #

    Wouldn’t the undersea volcanoes heating the water near the bottom, have more effect that a slight rise in air temperature?

    And wouldn’t the melting on the bottm of the ice self increase the stresses in the whole, causing it to crack off? Break loose?
    I mean the ice would float lower, since the overall volume would be reduced. The original shelf would be higher, setting up stresses in the ice, hence a big crack, just like the photos shows.

    It seems like natural processes to me.

  60. sod April 9, 2009 at 5:27 am #

    i am just reading a book about Pompeii, and it gives 2*10^18 joules as the thermal energy released during the A.D. 79 eruption.

    i will leave the rest of the calculations to you:

    http://www.science.uwaterloo.ca/~cchieh/cact/nuctek/energyheat.html

  61. Nick Stokes April 9, 2009 at 6:30 am #

    Thanks, sod, this silly volcano notion won’t stand up to any quantitative analysis. Vesuvius 79 was a huge eruption, and would have been highly noticeable under a coastal ice sheet. If all the thermal energy just went into melting ice (very unlikely) it would melt about 6 gigatons. Sounds a lot until you realise that that would be about 40cm depth of the Wilkins shelf.

  62. dhmo April 9, 2009 at 8:25 am #

    Does anyone have a reference to the temperature measurement data that shows this rise of 3 degrees in 50 years? As yet I have seen only assertions with nothing to back it up.

  63. cohenite April 9, 2009 at 8:33 am #

    Using the example of a large eruption is typically disingenuous; the proper analysis would be of an active but non-erupting volcano with sustained heating which over a relatively short period of time would express heat to the surrounds of an accumulative amount much greater than the one-off from an eruption;

    http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VCS-3Y9RNFS-D&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=ceb3fe807c40f9969ec53bbf9b904617

    In any event dhmo is correct; there has been no temperature increase at the Antarctic.

  64. Luke April 9, 2009 at 8:47 am #

    And on and on they go chasing the “mysterious” volcano ignoring a bloody massive change in Antarctic circulation – are you guys clowns or what?

    Cohers resorts to sophistry – there’s a huge rise in Peninsula temperatures. (try googling DHMO)

    And that’s why they call you guys DENIALISTS !

    If it’s too much guys try this http://www.youtube.com/watch?v=tqyxXX3Ra4A&feature=related

  65. Ian Mott April 9, 2009 at 8:54 am #

    Could someone explain to gavin and Stokes that yes the ice sheet is floating. But as it is ICE, 90% of it is below sea level. And as the portion above the water appears to be more than 50 metres then we can conclude that the bottom of the ice is 450m below sea level. And the suggestion that the water at this depth might have been warmed up during a brief 6 week summer is ludicrous.

    The suggestion that warmer surface water from further away might have been forced this far under the ice sheet without serious mixing with the larger volume of cooler water below is also quite silly. But Luke likes to supply us with the latest drivell from Scambos. He calls it data but Scambos rarely provides the actual substantiation for his public statements.

    So lets see the actual data that shows a 3C warming over 50 years. My understanding is that most of this warming has registered in the form of milder mid-winter temperatures which all remain well below zero C.

  66. Louis Hissink April 9, 2009 at 8:57 am #

    Just love the way the non geologists wax so lyrically about geology from crass ignorance.

    A volcanic eruption means that the themal flux in a REGIONAL sense has increased or surged – the thermal flux is not concentrated on an itty bitty area limited to the volcanoe itself, but is merely the rupture of magma at the structurally weakest point under a broader regional thermal hotsopt. Quite clearly a signficant increase in subsurface temperature has had to occur over a long period of time, to melt the lower lithosphere to produce the volcanism.

    Any thermal surge under the ice would not be noticed from surface themometers, the ice itself being a pretty good insulator (Ask Ekimos about the insulating effect of igloos).

    There is a reason the IPCC doesn’t have any signficant geological input into its deliberations – AGW is basically B…S…..

  67. david elder April 9, 2009 at 9:08 am #

    Erratum: In my post I incorrectly in one place referred to an ‘Arctic Peninsula’. I meant of course the Antarctic Peninsula. I say Sorry for this error. My brain overheated due to global warming . . . I still don’t see why AGW should produce a 5-fold greater warming on the Antarctic Peninsula than the global average, or why AGW warming on the peninsula should dwarf the feeble warming in the Antarctic in general since the early 1970s. Of course I don’t expect totally uniform AGW, but this case is extraordinarily non-uniform and I am not convinced we understand it.

  68. Luke April 9, 2009 at 9:12 am #

    Why is the Argentine Island of Orcadas also showing warming? http://www.bom.gov.au/events/9icshmo/manuscripts/PT_EFG32_Zazulie.pdf Table 1

    Do volcanoes only work at certain times of the year? Why is does the warming show seasonality. LOLZ !! http://www.scar.org/researchgroups/physicalscience/reader_turneretal.pdf

  69. david elder April 9, 2009 at 9:22 am #

    Interesting guest post by Goddard on Watts Up With That site, 8th April:

    “Looking at the Wilkins picture below, I’m having a very tough time seeing any evidence of melting around the fractures, or any evidence of water pooling on the surface. Normally, such fractures are caused by tensile or shear stress, likely due to a change in currents. Ice melts from the edges towards the center, and that ice is very thick – up to 200 metres. Blaming the clean fractures seen below on warming and melting seems highly questionable – at best. I suggest bringing some actual structural and mechanical engineers into the discussion – how’s that for a novel idea in the AGW world?”

    Any thoughts by anyone here down under on the plausibility of the change-in-currents shearing theory?

  70. SJT April 9, 2009 at 9:36 am #

    Aliens, people, what about the aliens?

  71. Louis Hissink April 9, 2009 at 9:37 am #

    David Elder

    Given the clean break shown in the image above, I would support Goddard’s interpretation that we are dealing with a mechanical failure, though the precise cause remains conjectural.

    If the ice is as thick as Ian Mott estimates it to be, then sea-ice of this magntitude would behave as a rigid plate and tidal motion could have caused brittle failure at the weakest point – close to land where there is no vertical movement possible, hence the break off of the ice.

  72. Nick Stokes April 9, 2009 at 11:40 am #

    Cohenite Using the example of a large eruption is typically disingenuous …
    Well, the “geologists” here produce no figures at all to back these speculations. But the paper you link to figures the heat from a sustained eruption at Etna, and quotes 7×10^16J/year (sec 5.4.2), compared to the Vesuvius quote of 2×10^18J for one major eruption. On that basis Etna could at most melt less than an inch a year of the Wilkins shelf.
    And with all that we have
    – no kinown volcanoes near Wilkins
    – no known eruptions.

    Ian Mott says :And as the portion above the water appears to be more than 50 metres then we can conclude that the bottom of the ice is 450m below sea level. And the suggestion that the water at this depth might have been warmed up during a brief 6 week summer is ludicrous.
    No-one is saying that the water at depth was warmed in just six weeks. But the water is relatively warm (it’s liquid) and in contact with the ice. The warmth which stops it from freezing comes from transport from the nearby sea. So that process exists, and if the nearby sea gets warmer (it has) then that adds more heat to the base.

  73. Bill Illis April 9, 2009 at 12:13 pm #

    The ocean temperatures in this region are only +0.227C right now from normal – they were negative until recently.

    This area should also be considered as part of the mid-latitudes. It is north of the south polar vortex and it has more in common with the southern tip of South America than Antarctica.

    I believe you can see this in this very fascinating 1-year, every-hour animation of cloud movements from NCAR (which should completely change how you view the climate and I hope gavin looks at it too.)

    https://www.ucar.edu/publications/nsf_review/animations/ccm3.512×256.mpg

  74. dhmo April 9, 2009 at 12:46 pm #

    Luke have you worked for Microsoft or IBM? They too give an accurate but totally useless answer. I guess I should be used to that from you by now.

    I ask those on this thread again do you know where there is any available data on this? It needs to be SST for the area near Wilkins Ice Shelf for the past 50 years. This is the basic premise of this whole thing. Without it, we might as well be discussing Bertrand Russell’s teapot.

    Maybe SJT’s belief in aliens is in fact valid.

  75. kuhnkat April 9, 2009 at 1:32 pm #

    Nick Stokes says:

    “The warmth which stops it from freezing comes from transport from the nearby sea. So that process exists, and if the nearby sea gets warmer (it has) then that adds more heat to the base.”

    I’m sorry for your inability to keep up on research Nick, but, you are WRONG!!!! The Southern Ocean has been cooling. Is that near enough for you??

    HAHAHAHAHAHAHAHAHAHAHAHAAH

  76. Louis Hissink April 9, 2009 at 1:38 pm #

    Nick Stokes,

    One of the reasons no one knows much about volcanic activity in this region is because no one is looking let alone collecting data. I doubt any such program would get finding either, given that any discovery of such “inconvenient facts” would be counter productive for one’s grants.

    The last submarine volcano in the Antarctic was accidentally discovered by the U.S. Navy as I recall. No one has budgets for this -it’s’ all spent on research that supports the fiction of AGW.

  77. dhmo April 9, 2009 at 1:48 pm #

    I finally found where this comes SST record comes from: http://faculty.washington.edu/steig/nature09data/ maybe.

    I need look at it more to be sure. If it is this then the Wilkins thing is a rehash of the same argument. Steig et al has been criticised from a number of quarters for this. Mainly on the data being incorrect because of faulty measurement I think. You can look at Climate Audit (where I found it) Lucia WUWT etc. Steigg is connected I think to Mann you know the hockey team.

  78. kuhnkat April 9, 2009 at 2:06 pm #

    Here are a couple of interesting articles giving more range to the dynamics of the Antarctica:

    http://www.spaceflightnow.com/news/n0203/06elninolinks/

    http://www.sciencedaily.com/releases/2006/12/061221075130.htm

    Oh, and Nick, here is an article reporting the 3 year old research finding the deep southern ocean cooling quickly:

    http://www.ocean.com/article.asp?locationid=0&resourceid=6940&ProdId=&CatId=271&TabID=&SubTabID=

    Now, as there is mostly upwelling around Antarctica…

  79. Louis Hissink April 9, 2009 at 2:06 pm #

    Well, well, it’s in a rather boring tectonic region, (I can look out of my window to the south and note that it’s just over the horizon), but as the southern ice cap has been growing, then we have the simple explanation of too much ice needing to part company with the ice manufacturing plant that seems to be in full production, even during Fall, at this pole.

    But the media hype sure has the “ignorati” waxing lyrically.

    So, no volcanoes but simply a variant of “glacial carving”.

    Raises the spectre of the HAB theory – the idea was that if the polar ice caps grew too large, they would imbalance the earth and cause it to careen into a more stable orientation.

    Thank goodness for all the ice breaking off into the Southern Ocean then, imminent careen delayed.

  80. Louis Hissink April 9, 2009 at 2:07 pm #

    Whoops “calving” – IE8 is merciless.

  81. janama April 9, 2009 at 2:17 pm #

    It could have come from here.

    http://earthobservatory.nasa.gov/IOTD/view.php?id=8239

  82. Nick Stokes April 9, 2009 at 2:21 pm #

    Kuhnkat I’m sorry for your inability to keep up on research Nick, but, you are WRONG!!!! The Southern Ocean has been cooling. Is that near enough for you??
    David Vaughan keeps up, and he says air temp has risen 3C in 50 years. Do you have evidence for your assertion? Here is a pretty convincing recent article showing rapid sea temp rise on the W Antarctic Peninsula.

  83. Nick Stokes April 9, 2009 at 2:22 pm #

    Oops, missed that link. W Antarctic Pen SST

  84. SJT April 9, 2009 at 2:40 pm #

    “Maybe SJT’s belief in aliens is in fact valid.”

    Prove me wrong 😉

  85. Jan Pompe April 9, 2009 at 2:46 pm #

    “Maybe SJT’s belief in aliens is in fact valid.”

    Prove me wrong 😉

    Will you confess to being one if we do:-P

  86. kuhnkat April 9, 2009 at 3:17 pm #

    Nick states:

    “Kuhnkat I’m sorry for your inability to keep up on research Nick, but, you are WRONG!!!! The Southern Ocean has been cooling. Is that near enough for you??
    David Vaughan keeps up, and he says air temp has risen 3C in 50 years. Do you have evidence for your assertion? Here is a pretty convincing recent article showing rapid sea temp rise on the W Antarctic Peninsula.”

    Lemme see, air temp rises 3c. I’m sorry Nick, did I even mention air temp?? This 3c rise, how close does it bring the summer temps to 0c?? I believe that statement qualifies as a STRAWMAN!!!!

    By the way, did you even bother reading the Steig paper that showed all the increase was up to the 70’s at which time it has been slowly dropping?? Yeah, that NET 3c really does a job 30 years later!!

    I do not have access so can say nothing about the validity of the research. The abstract mentions a SUMMER SURFACE increase of 1c. Sounds pretty substantial. Of course, I have no idea how many measurements were taken over what period of time, and over what area. Until you can provide this information I will table the sea temp idea, especially since it does NOT mention subsurface temps. You do realise that surface water temp can not affect the area where the shelves break off?? It also does not mention the actual delta over the year compared to anything.

    Get us a copy why don’t you???

    I would also point out that the Wilkins Ice shelf is so small it doesn’t even get a mention on most Antarctic maps!! As big as Connecticut?? I have to drive further to my state capitol!! Of course, I do live in San Francisco. (my own strawman!!)

    Seriously, read through the articles I linked. The collapse of the shelf very well may not have been induced by volcanism or other heating. The normal sea level rise and fall is guaranteed to stress EVERY shelf and break it off over time!!!! You know, just like moving glaciers, whether expanding or contracting calve?!?!!?

    HAHAHAHAHAHAHAHAHA

  87. Gordon Robertson April 9, 2009 at 4:23 pm #

    Nick Stokes “David Vaughan keeps up, and he says air temp has risen 3C in 50 years”.

    Nick…here’s what the satellites were seeing in Dec 2008:

    http://climate.uah.edu/

    Don’t forget that’s the SH summer beginning. Looking back to Aug 2008, things get a whole lot cooler, down to -6.5 C:

    http://climate.uah.edu/august2008.htm

    Here’s the 25 year global report:

    http://climate.uah.edu/25yearbig.jpg

    The yellow in the Antarctic region is +0.1 C to +0.3 C. The blue regions are small negative values. I don’t pretend to be an expert in intepreting UAH graphs, but it sure looks to me like the Antarctic survived the warming of the Arctic, which, on average is about 1 C positive.

  88. Ian Mott April 9, 2009 at 4:39 pm #

    Nick Stokes. The mean monthly SST at Wilkins was zero C in March 2009. See http://www.bom.gov.au/climate/current/meansst.shtml

    It follows that it might have been a bit higher in Dec, Jan & Feb but we can be quite certain that it was, and will be, colder in all the other months. You do accept that the reason Antarctica is cold is because of the short exposure to direct sunlight, don’t you.

    So all these references to “warming trends” etc are pure bull$hit if they do not make reference to the actual temperatures at the site. Clearly, 3 months of minimal solar radiation is not enough to warm surface water, let alone 200-300m deep water, to a point where it will have any impact on 140km2 of solid ice. The mixing required to get surface water that deep would spread the heat so thin that it would have minimal effect on such a huge thermal mass.

    Meanwhile, the weight of precipitation accumulation above is far more certain and more precisely measured. Get the numbers, man. Thats 90 million tonnes per km2 x 140km2 makes for a huge amount of leverage at the land ice fulcrum. And it increases each year.

    On the top we have an increase in mass of 9 metres per square metre of ice sheet over 50 years. And all you climate retards can come up with is vague warmenista voodoo that would have us believe that a greater amount of mass loss will take place as a result of 3 months of sea surface warming mixed with 300 metres of ocean profile. Give us a break.

  89. Nick Stokes April 9, 2009 at 4:39 pm #

    Kuhnkat I’m sorry Nick, did I even mention air temp?? This 3c rise, how close does it bring the summer temps to 0c??
    That paper firstly is a source for the 3C claim, queried above, and also explicitly compares it with SST. However, here is a free read paper written by biologists, but surveying the recent papers on air and sea warming in this region. There are various figures, but they are all rising.

  90. Gordon Robertson April 9, 2009 at 4:42 pm #

    Matthew Slyfield “I look at that video and to me it screams mechanical stress, not warming whether from the top or the bottom”.

    One thing that has not been mentioned is the tremendous stresses of wave action on the ice. The ocean just north of there is known for its storms and waves up to 100 feet high. Whereas I don’t know how that would affect an ice shelf hemmed between an island and the mainland, the up and down action of large waves has to be stressful.

    When Skackleton went through there a century ago, he commented on the huge bergs. It has only been recently that we’ve had observers there on the peninsula and satellites are pretty new as well.

  91. Gordon Robertson April 9, 2009 at 4:43 pm #

    Ooops, Skackleton was actually Shackleton’s alter ego.

  92. sod April 9, 2009 at 6:10 pm #

    30 new comments, and not a single “sceptic” came up with any calculations or any evidence that volcanoes produce the heat required.

    the same people who question the MEASURED temperature increase at the surface, simply BELIEVE that an unknown volcano is SOMEHOW producing the heat to melt the ice.

    and talking about another (absurd) line of argument: of course mechanical stress played a significant role in breaking the THIN ice bridge. please try to counter our arguments, and don t make up your own stuff!

  93. Luke April 9, 2009 at 6:13 pm #

    Well DHMO – I’m so sorry you didn’t get 150 years of data from under the Wilkins ice. Vaughn’s seals might help. I thought some seasonal variations in the stations and a long term record of an Argentine station in the passage may have told you something about maritime climate. But hey let’s ask for the ridiculous.

    Maybe SJT is right – maybe it’s aliens. Cleverly living under the ice. But perhaps you guys are the aliens. Me I’m just the Borg.

    Anyway dudes – as you were – just ignore all the met obs and circulations changes. We pretend to agree – yes it’s a volcano – will you now GO AWAY !

  94. cohenite April 9, 2009 at 6:13 pm #

    Nick says; “On that basis Etna could at most melt less than an inch a year of the Wilkins shelf.”

    Sometimes an inch can go a long way; the point is the Wilkins was not melting, it was expanding; generally sea ice is increasing around the whole of the Antarctic; how does that tally with the alledged 3C warming [the Meredith and King paper is on a par with Steig]; also, how does it tally with the expansion of the land ice?

  95. Kohl Piersen April 9, 2009 at 6:16 pm #

    Luke said (inter alia) – Volcanism – what a joke !
    Well I don’t agree with much else that Luke says, but blaming the calving of pieces off of the iceshelf does not seem to me to be at all likely.

    On the other hand, I don’t see that “melting” has anything at all to do with it either. Let’s face it, split into pieces or not, most of the ice is extant; it has not melted.
    In other words, even at a very general lev el of observation, the event(s) seem to point to a mechanical explanation not a thermodynamic explanation. There has been a ‘breaking’ up of the ice, not a melting.

    Of course, what happens now depends upon the currents, winds and weather. But on past large berg events, the calved ice is likely to be around for a long time yet.

    I agree with others on this thread who have pointed to the mechanical factors as being the principal cause, and I think those who explain the event(s) by rises in temperature are simply wrong.

    P.S. Of course, that is only my opinion. I do read and value the opinions of others on these and other matters whether or not I agree with them.

  96. Nick Stokes April 9, 2009 at 6:38 pm #

    Ian Mott Clearly, 3 months of minimal solar radiation is not enough to warm surface water, let alone 200-300m deep water, to a point where it will have any impact on 140km2 of solid ice.
    There’s an obvious problem with this argument. Under the ice is liquid water. It has been there for a very long time, and has ice above and insulating solid beneath. By your argument, since it must conduct heat to the colder ice above, it could not stay liquid. But it does.

    The reason is that it gets heat by mixing from the neighboring sea. The broad pattern of longitudinal movement (thermohaline circulation in the Southern ocean is poleward near the surface, conveying warmth, and northward at depth, taking away colder water which helps to keep the tropical depths very cold. As you point out, a lot of snow accumulates on these shelves. But it doesn’t pile up indefinitely. Something melts it, and that is mainly this flow of oceanic heat – not heat from the generally colder air or sunlight.

    As with all such heat flows, there is a general balance between supply and losses. The ice and ocean lose heat to the air when it is colder. If the air is less cold, even if <0C, the rate of loss is reduced, and more of the ocean mixing warmth can go to melting ice.

  97. Louis Hissink April 9, 2009 at 7:20 pm #

    Nick Stokes

    Only an ignoramus would write “Under the ice is liquid water”.

  98. Louis Hissink April 9, 2009 at 7:29 pm #

    Nick Stokes.

    In addition, if the ambient surface temperature is < 0 degrees Celsius, then H2O occurs as the stable phase ice, (everything else being equal). Phase changes < 0 degrees Celsius for H2O is not on the agenda from empiricism. Ice is ice.

    You seem to be advertising, in an alarming manner, your ignorance of physical processes.

  99. Nick Stokes April 9, 2009 at 7:45 pm #

    A couple more references. The M&K paper (with the 3C in 50yr claim) costs, but there is a PPT set here.

    A more recent (free) paper by Gillies et al on SH Ocean temperatures, based on floats, is here.

  100. Nick Stokes April 9, 2009 at 7:52 pm #

    Louis “Only an ignoramus would write “Under the ice is liquid water”.”
    Louis, could you explain? It’s a floating ice shelf. What do you think it is floating on? Oil?

    I didn’t get your next post at all. Whenever ice and water are stably adjacent to each other there is a dynamic equilibrium. If there is a slight increase in heat ice will melt – a slight loss of heat, water will freeze. That’s why the phase surface has to be at the equilibrium temperature (melting point).

  101. david elder April 9, 2009 at 8:15 pm #

    Reply to sod: he tells us that his pro-AGW view is proved by measuring temperature at the surface. Very well, let us measure temperature at the surface. We then find that there has been no appreciable temperature rise in Antarctica as a whole since the early 1970s. This finding is in several papers including the recent Steig et al paper. See World Climate Report ‘Antarctica Again’ Jan. 30, 2009 for the references for this finding. It contradicts sod’s view.

  102. Louis Hissink April 9, 2009 at 8:21 pm #

    Nick Stokes.

    “Louis “Only an ignoramus would write “Under the ice is liquid water”.”
    Louis, could you explain? It’s a floating ice shelf. What do you think it is floating on? Oil?.

    Nick, liquid water?

    Come back when you understand it.

  103. cohenite April 9, 2009 at 8:26 pm #

    Then there is this showing the Antarctic deep waters are getting colder;

    http://idw-online.de/pages/de/news256486

  104. James Mayeau April 9, 2009 at 11:34 pm #

    Since no one has been able to disprove SJT’s theory, I invoke the precautionary principle.

    All Antarctic explorers must here by be assumed to be shape shifting aliens who have co-opted their host’s human body.
    We can’t take the risk that these extra terestrial beings are a benign species. We must exterminate them to ensure there is no contamination of the general biota. Flame thrower is the time tested method recommended by Hollywood sci-fi features, and historical accounts of pestilence carrying vermin infestations.
    Since all visitors to the Antarctic, and the people they have come into contact with subsequent to their trip are potential carriers, time is of the essence. There is no room for delay or debate.
    For the more empathetic reader who thinks this a harsh method, remember the Antarctic explorers brought this on themselves by digging up the alien spore from it’s otherwise eternal hybernation under the perpetual ice.

    and thank goodness SJT brought this matter to our attention, not a minute too soon!

  105. Dave April 9, 2009 at 11:54 pm #

    Let me help Nick out….

    Solid = Ice
    Liquid = Water
    Gas = Steam

    water is the liquid state of H20.

    “liquid water” is an example of tautology.

  106. Luke April 10, 2009 at 12:05 am #

    Nick (7:45pm) – please don’t try and add actual information into the debate. The fragility o fthe denialist ego is at stake.

    Guys pls pls don’t read Nick’s links – could cause a massive cognitive dissonance attack. We wouldn’t want you learning anything now would we?

  107. Nick Stokes April 10, 2009 at 7:07 am #

    Er, thank you Dave … so there’s no water in the atmosphere, only steam … gosh, you can’t be too careful.

  108. david elder April 10, 2009 at 9:04 am #

    Maybe someone can help me out. The Antarctic as a whole has not warmed since the early 1970s (see my post above). But I am curious about the Antarctic Peninsula which has warmed remarkably. Does anyone know of any measurement of the time course of the peninsula’s warming?

    Happy Easter to Jen and all, sceptics or greens – hey, it’s Easter!

  109. Nick Stokes April 10, 2009 at 9:20 am #

    David E
    There are station graphs and decadal maps in this M&K PPT.

  110. Nick Stokes April 10, 2009 at 10:29 am #

    For people who are interested in how heat flows into floating ice sheets, there is an informative plot in a post by Steve Goddard at WUWT. It shows a buoy embedded in Arctic ice – only 2-3 m thick, but the principle is the same. The buoy is instrumented for temperature, right from where it sticks into the sea below to the air above, and has temp profiles for a few days.

    It shows first a steady temp of -2C where it sticks into the water below. That is the freezing point of sea water. As you go up from there, there is a linear temp gradient, getting cooler, until near the top, where the temp gradient firstly takes a steep dive (shown as a shallow slope here, because temp is the x-axis), then levels at the air temp.

    So the heat is flowing from the bottom to the top. Most is steady flow – the steep grad at the top is probably a transient caused by the air having recently cooled.

    Bottom line – it shows clearly that the ice is heated from below, and melting when it occurs, will be at the bottom surface. Since the sea water is constantly supplying heat, it in turn has to be warmed by (slightly) warmer water at greater depth.

  111. Eric Adler April 10, 2009 at 12:07 pm #

    Comment from: janama April 8th, 2009 at 1:46 pm

    I’m sorry BUT Dr Vaughan stated last year in january 2008 that the cause of the ice shelf melt was the still active volcano that they had just discovered. Do a google search for “volcano under wilkins ice shelf, Dr Vaughan”

    That’s why he won’t say it’s AGW!! he believes what he said last year still obviously.

    Vaughn does not agree with you., based on the results of the search you suggested.
    First of all Vaughan definitely blames global warming for the collapse of Antarctic Ice Shelves:

    http://feww.wordpress.com/2009/01/20/wilkins-ice-shelf-is-hanging-by-a-thread/

    WARMING TO BLAME

    “This ice shelf and the nine other shelves that we have seen with a similar trajectory are a consequence of warming,” Vaughan said.

    In total, about 25,000 sq km of ice shelves have been lost, changing maps of Antarctica. Ocean sediments indicate that some shelves had been in place for at least 10,000 years.

    http://feww.wordpress.com/2009/04/05/emerging-patterns-of-vanishing-ice-shelves/

    “We believe the warming on the Antarctic Peninsula is related to global climate change, though the links are not entirely clear,” Vaughan said.

    http://www.timesonline.co.uk/tol/news/environment/article3621685.ece

    The Wilkins Shelf is farther south than other ice that has retreated, and should thus be protected by colder temperatures. But Professor Vaughan said: “Climate warming in the Antarctic Peninsula has pushed the limit of viability for ice shelves further south, setting some of them that used to be stable on a course of retreat and eventual loss.

    The importance of it is that it’s farther south than any ice shelf we’ve seen retreating before, it’s bigger than any ice shelf we’ve seen retreating before, and in the long term it could be a taste of other things to come. It is another indication of the impact that climate change is having on the region.”

    Second, the article you are thinking of is not about the Wilkins Ice Shelf at all. It is about the Pine Island Glacier. That is quite another story.
    http://www.environmentalgraffiti.com/sciencetech/volcano-not-global-warming-effects-may-be-melting-an-antarctic-glacier/714

    Hugh F.J. Corr and David G. Vaughan, two scientists with the British Antarctic Survey, recently published their discovery of the volcanic layer in the journal Nature Geoscience. The discovery is unique according to Dr. Vaughan. He said “This is the first time we have seen a volcano beneath the ice sheet punch a hole through the ice sheet.”

    The volcano’s heat could possibly be melting and thinning the ice and raising the speed of the Pine Island Glacier in West Antarctica.

    But while the Pine Island Glacier may be thinning because of the volcano, it’s highly unlikely the thinning of Antarctica’s ice sheet as a whole can be blamed on hidden volcanoes. For one thing, Antarctica has very few active volcanoes. Most glacial scientists, including Dr. Vaughan himself, blame warmer ocean waters for glacial thinning in West Antarctica.

  112. cohenite April 10, 2009 at 12:52 pm #

    Nick says;

    Since the sea water is constantly supplying heat, it in turn has to be warmed by (slightly) warmer water at greater depth

    But where does this warmer water come from when this is happening;

    http://www.sciencedaily.com/releases/2008/04/080421111622.htm

  113. Luke April 10, 2009 at 1:13 pm #

    I know where. It’s from a volcano. hahahahahaha LOLZ

  114. cohenite April 10, 2009 at 1:42 pm #

    It’s probably fair enough to conclude that volcanic activity is not playing a part at Wilkins;

    http://wattsupwiththat.files.wordpress.com/2008/01/antarcticvolcanoes2.jpg

    But the underpining rock platform of Antarctica is interesting;

    http://en.wikipedia.org/wiki/File:AntarcticaRockSurface.jpg

    The thing to remember is that the ACC strikes the West coast of Antarctica and either diverges around it or sinks; with the rock underpining there is a natural funnel underneath Wilkins which would place continual current stress on this area; the area around Wilkins is subject to constant current activity to a much greater extent than any other part of the Antarctic coast; given that sea ice-levels are above normal;

    http://arctic.atmos.uiuc.edu:80/cryosphere/IMAGES/current.365.south.jpg

    the issue has to be why there is some loss on the West Coast only if this is due to AGW and not just a normal pattern of ice level variation.

  115. Gordon Robertson April 10, 2009 at 1:53 pm #

    sod “…and talking about another (absurd) line of argument: of course mechanical stress played a significant role in breaking the THIN ice bridge”.

    Are you aware of the power in a 100 foot rogue wave? Smaller waves take sailing boats and flip them butt over tea kettle. Over a long period of time, wave action will flex an ice-shelf.

    Check here:

    http://www.independent.co.uk/environment/climate-change/cracking-up-the-ice-shelf-as-big-as-northern-ireland-800585.html

    and read “Dr Scambos said: “We believe the Wilkins has been in place for at least a few hundred years. But warm air and exposure to ocean waves are causing a break-up… .”

    Now just remove the warm air and you have ‘exposure to ocean waves’.

    Really sod, do we skeptics have to show you everything?

  116. david elder April 10, 2009 at 2:13 pm #

    Thanks to Nick Stokes for kindly sending me a file on the Antarctic Peninsula. Unfortunately I can’t open the darn thing – not sure if it’s my internet setup or just my low skills in using it. Is there any way Nick or someone could post on Jen’s site a good graph of temperature vs. time for the Antarctic Peninsula? As noted in my post above, most of Antarctica stopped warming in the early 1970s – awkward for strong AGW. But the Antarctic Peninsula may be an exception, and if so one needs to know why.

  117. Gordon Robertson April 10, 2009 at 2:24 pm #

    Here’s more on wave action. Mind you it’s prefaced by warming theory that claims the sea ice is thinning and allowing the waves to get at the ice shelves.

    http://antarcticsun.usap.gov/science/contenthandler.cfm?id=1408

    “Meier explained that the sea ice serves as a buffer between the ice shelf and ocean waves, which can pummel an unprotected ice shelf, causing it to flex, particularly if it has been weakened by melt ponds, pools of open water on the ice surface that absorb rather than reflect heat.”

    So what we’re dealing with here is occuring within the parameters of minor warming IN THE SUMMER. The buffer ice normally protects the shelves from ocean waves, but due to melting buffer ice, the waves are getting at the ice shelves.

    What’s the big deal?

    Here’s a skeptical argument that I haven’t had a chance to analyze:

    http://icecap.us/images/uploads/Wilkins_Ice_Shelf_con.pdf

  118. Gordon Robertson April 10, 2009 at 2:28 pm #

    david elder…re temperatures in Antarctic…take a look at the file I just posted. Not sure if there’s helpful info there or not. They are claiming the climate has not changed significantly. Also, look on the site itself, icecap.us

    http://icecap.us/images/uploads/Wilkins_Ice_Shelf_con.pdf

  119. sod April 10, 2009 at 3:06 pm #

    and read “Dr Scambos said: “We believe the Wilkins has been in place for at least a few hundred years. But warm air and exposure to ocean waves are causing a break-up… .”

    Now just remove the warm air and you have ‘exposure to ocean waves’.

    Really sod, do we skeptics have to show you everything?

    you missed my point. i wrote:

    of course mechanical stress played a significant role in breaking the THIN ice bridge.

    everybody with any knowledge on the subject will agree with the notion that mechanical stress was involved in the break up. denialists love to pretend, that people who believe in the warming deny this. we don t.

    instead we fully agree with the statement that you cited:

    But warm air and exposure to ocean waves are causing a break-up

  120. cohenite April 10, 2009 at 3:53 pm #

    The Antarctic is not warming, although it is fair to say that the WAP is a distinct climate region; Nick’s various articles are fodder; Meredith and King’s claim of a 3C increase since 1951 must be treated with disdain; the Clarke et al paper’s conclusion of deep water warming is in contradiction to the recent extensive surveys by the Polarstern expedition while the Gillie effort concludes with this gem;

    “Overall, the results indicate that the Southern hemisphere ocean has warmed substantially since the 1930s. Some 80% of this warming is concentrated south of 30 degrees soutn where it is evident at all depths. Observations are also sparsest in this latitude range. Estimates of the exact amount of warming that has occurred therefore depend on the details of the assumptions made about temperature trends in regions where no observations are available, as studies based on numerical climate simulations.” [p4761]

    It is not virtual science but Groucho science; who are going to believe: me or your own eyes?

  121. janama April 10, 2009 at 4:59 pm #

    recent WUWT post is:

    NASA GISS suggests aerosols play a large role in Arctic warming – 45% or more

    http://wattsupwiththat.com/2009/04/09/nasa-giss-suggests-aerosols-play-a-large-role-in-arctic-warming/#more-6922

    could this also be the cause of WAP warming?

  122. Nick Stokes April 10, 2009 at 5:26 pm #

    David E
    The file I linked to is a Powerpoint file. I don’t know what your platform is, but I expect Internet Explorer should bring it up, if you have Powerpoint (MS Office). I’m using Firefox on Linux, and it came up in Open Office. It’s worth persisting a bit, because I think it is close to what you want.

  123. Nick Stokes April 10, 2009 at 5:35 pm #

    Coho,
    I would read that ScienceDaily article on the Wegener expedition carefully. They don’t say how much the water cooled, or over what time period. My suspicion is that the journalist is ad-libbing based on the remark that last summer was cold, and so the downwelling water must have been too (which could be true).

    However, the idea that cooling is possible is a clue. The water adjacent to the ice is at -2C. That is freezing point – the coldest water can remain liquid, and so it is the coldest point in the ocean. Any water that can cool must be warmer than this. In fact the circulation goes thus – warmer water comes from the north, cools by contact with the ice, and descends. This is the descending water that the Wegener people are talking about. And this warmer incoming water is the source of warmth.

  124. Nick Stokes April 10, 2009 at 5:42 pm #

    Gordon,
    Both warmth and wave action contribute to breaking up a shelf. But wave action has always been there, and there’s no reason to suppose it’s unusually strong now. The warming is new. Three big shelves (Larsen A and B and Wilkins) have now gone or are going. The Larsen shelves had been there thousands of years, and Scambos is saying that Wilkins has also been there a long time.

  125. Nick Stokes April 10, 2009 at 5:53 pm #

    Coho,
    a followup on heat source. If you look at the file that Gordon linked, fig 4 shows the history of SST’s near Wilkins. I think they have been increasing, although you might argue. But the important point is that they are generally >0C. That’s why heat flows to the lower ice surface, at -2C.

  126. Nick Stokes April 10, 2009 at 6:01 pm #

    Janama,
    What that WUWT-linked article says is that man-made (industrial) aerosols have a cooling effect, and that the warming is caused by the reduction in aerosols following the Clean Air Act, etc. There weren’t significant such aerosols near the WAP at any stage.

  127. Nick Stokes April 10, 2009 at 6:57 pm #

    Coho,
    A followup on my followup. I misread that Fig 4, looking at anomalies instead of monthly temps. The SST’s vary from about -1.5 in winter to generally >0 in summer. They are still warmer than the ice interface.

  128. cohenite April 10, 2009 at 7:02 pm #

    Nick; the Science daily report is from here;

    http://idw-online.de/pages/de/news256486

    In respect of Fig 4 of the McLean piece I agree there is some warming; this is what McLean says underneath it when he refers to the slightly warmer period from 1998-2004; that was the tail end of the +PDO; given that the ACC flows into the WAP, which bears the impact of that water from the higher latitudes before it is redistributed according to the Antarctic structure, that warmer period from 1998-2004 is consistent with the prevailing world conditions, which have cooled since then; this is what the Polarstern findings showed; the next round of samplings will be crucial as to indicating a downward trend which would reflect natural factors, or an upward trend which would be harder to explain by natural means. But really the papers which show this 3C can’t be taken seriously.

  129. janama April 11, 2009 at 7:18 am #

    There weren’t significant such aerosols near the WAP at any stage.

    Nick – as I see it , especially following that great link posted by Bill showing the action of clouds

    https://www.ucar.edu/publications/nsf_review/animations/ccm3.512×256.mpg

    that all the aerosols produced in the SH eventually end up running into the WAP as it sticks out of the Antarctic up into the prevailing winds.

  130. Gordon Robertson April 11, 2009 at 9:06 am #

    janama “NASA GISS suggests aerosols play a large role in Arctic warming – 45% or more….
    could this also be the cause of WAP warming”?

    I don’t know if your question is tongue-in-cheek humour, but IMHO, it’s more of Hansen-type stupidity. Hansen’s theory about Arctic warming is ‘soot on the snow’. The rocket scientists at GISS are so myopic they have trouble seeing beyond their noses.

    As you no doubt are aware, aerosols were introduced to balance the skewed model outputs. Since they were reading high, the rocket boys could not get it in their heads that the models might be wrong, so they went looking for a reason. That’s when aerosols came into prominence. That is, the models were right but something was cooling the atmosphere. The problem was that aerosols are far more prominent in the NH which was warmer than the SH.

    Now they are using aerosols as a warming agent rather than a cooling agent. It’s really amazing how the mind of a pseudo-scientist work. Maybe it’s a case of aerosols on the brain.

  131. Gordon Robertson April 11, 2009 at 9:37 am #

    Nick Stokes “Both warmth and wave action contribute to breaking up a shelf. But wave action has always been there, and there’s no reason to suppose it’s unusually strong now”.

    I have no problem with the notion of warming in the WAP, I think the key to the matter is that the ice shelves have been protected from wave action by sea ice, which is now diminished due to the warming. Duncan Wingham pointed out at least a year ago there was warming in the peninsula but he thought it might be due to warmer ocean currents. He claimed it was unfortunate that the warming did not come conveniently labeled as being anthropogenic.

    Wingham has been studying the entire continent with satellites and he claims warming has been an issue at various points but, overall, the Antarctic is cooling and it’s ice is thickening.

    http://www.cpom.org/research/djw-ptrsa364.pdf

    http://www.nationalpost.com/story.html?id=b228f4b0-a869-4f85-ba08-902b95c45dcf&k=0

  132. janama April 11, 2009 at 9:40 am #

    Yeah – well it wasn’t tongue in cheek humour but I appreciate your humour regarding the rocket scientists. 🙂

    As I’ve said before – no one has adequately explained the warming of the arctic or the WAP. The satellite records show that the SH, Tropics and Antarctic have NOT warmed in the past 30 years. In fact the satellites say the antarctic has cooled slightly.

    http://users.tpg.com.au/johnsay1/Stuff/hemitemps.jpg

    http://users.tpg.com.au/johnsay1/Stuff/hemitemps_1.jpg

    Something is causing this warming yet it accounts for all the global warming.

  133. Gordon Robertson April 11, 2009 at 10:00 am #

    With respect to the myopic studies of GISS in the Arctic, here is a link to a study done circa 1997 at a conference to study Arctic warming at the University of Washington. This was obviously well before the hysterical IPCC AR4 report and the article actually examines causes of the warming, like the AMO.

    http://mclean.ch/climate/Arctic_1920_40.htm

    This PDF is linked in the article and there is a lot of good stuff in the indices (indexes, in the vernacular). There is one titled ““Arctic Warming” During 1920–1940: A Brief Review of Old Russian Publications”, which is previewed in the previous link.

    http://psc.apl.washington.edu/publication/Arctic_Change/arctic.pdf

    It obvious that Arctic warming is far more complicated than meets the eye. Since it was an issue between 1920 and 1940, where the US record year for temperatures (1934) is found, that pretty well rules out aerosols and anthropogenic sources.

  134. Gordon Robertson April 11, 2009 at 2:22 pm #

    janama “Something is causing this warming yet it accounts for all the global warming”.

    Here’s another interesting comparison of satellite data:

    http://climate.uah.edu/

    There are significant hotspots in the NH in the range +4.5 C to +5.5 C in Dec 2008. There are also significant spots of cooling (-2.5 C to – 3.5 C) in both the NH and Sh and one cooling spot (-2.5 C to -3.5 C) amid the NH hotpspots.

    Now roll back to July 2008:

    http://climate.uah.edu/july2008.htm

    Most of the Arctic warming is gone, even though that’s when the loudest howls come out about the Arctic melting. It’s much warmer, relatively, in the winter than in the summer.

    Now move to August 2008:

    http://climate.uah.edu/august2008.htm

    You see a tiny hotspot over Hudson’s Bay (+ 3.5 C to +4.5 C) and a large cooling over Antarctica (- 5.5 C to -6.5 C). The thing that strikes me on all the charts is how much is in the range – 0.5 C to + 0.5 C, which means essentially no warming or cooling. Also, the vast amount of the Earth that are cooler than normal.

    If this is ‘global’ warming, why is it so localized? And why is the Arctic so localized? How do those blue cooler spots move up into the Arctic between hotposts? That, to my uneducated eye, is more a sign of circulation than global warming.

    Let’s not forget that the correct term is globally-averaged warming. Even if someone with his head firmly stuck in the sand wants to argue that there are errors in the satellite data, that doesn’t explain the localization of the warming/cooling.

  135. cohenite April 11, 2009 at 8:37 pm #

    Gordon; maybe someone should try and correlate those localised hotspots with Gore’s travel movements.

  136. Gordon Robertson April 12, 2009 at 3:22 pm #

    cohenite “maybe someone should try and correlate those localised hotspots with Gore’s travel movements”.

    He’s got the opposite effect, I think it’s known as the Gore effect. Evey time he shows up to do a talk, it’s freezing cold.

    http://www.politico.com/news/stories/1108/15931.html

    Actually, there’s a character in the Al Capp comic strip ‘Li’l Abner’ who runs around with a perpetual rain cloud over his head. I thought it was Evil-eye Fleegle but it may be Joe Btfsplk, the guy with the unpronouncable last name, that sound like someone making a rasperry sound. He’s a jinx.

    http://www.enterstageright.com/archive/articles/0704/062804joebtfsplk.jpg

    He reminds me of Al Gore, but Evil-eye Fleegle had the power to emit energy from his eyes, thus the beginning of the ‘double whammy’.

  137. Ice Beard April 13, 2009 at 11:27 pm #

    G’day,
    Can I ask all of you what might be a really silly question.
    Has anyone of the contributors to this debate been to Antarctica, actually touched an iceberg, let alone an ice shelf?

    Find out on the Australian Antarctic Divisions Website about ‘Loose Tooth’, at the Amery Iceshelf, how long it takes for just a small ‘stock standard iceberg’ (20 x 30 k’s or so) to break off; how long it takes and what is involved.

    You argue to and fro whether it might be volcanic activity or not that speeds up the breakup of the Wilkins Iceshelf; why would it be so impossible? It’s far more likely and plausible than the politically correct global warming theory.

    Climate change is definitely not driven by us people driving our cars around and a few powerhouses.

    Why couldn’t we in fact have ocean warming causing global warming? The oceans and what happens in them are less well known than space!! Only recently they found the signs and symptoms of a huge volcanic eruption in the Arctic Ocean, some 4,000 m deep. None of the scientists thought it possible to have an explosive eruption like that at that depth. One of the professors commenting on it reckons that, yes, the Co2 output from it would have been measurable in our atmosphere but he doesn’t believe that would have contributed to the disappearing sea ice in the Arctic Ocean region. Hello!?!
    (And yet there is a definite downward spike, around 1997, on the graph.)

    What about the slowing down of the Gulf Stream? Is it possible that we have in fact totally new ocean currents forming and developing, who knows, especially in the area around The Antarctic Peninsula?

    There is a theory that a connection exists, deep under the ice for water to flow, between the Ross and Filchner Iceshelfs. Has something like that anything to do with the Wilkins Iceshelf; although it shouldn’t, it’s on the other side of the peninsula.

    Why couldn’t there be extremely hot mud pools under the ice near the Wilkins iceshelf, rather than actual volcanos? You have them in New Zealand. The heat from those could easily create huge melt-bell like caverns under the ice, in the valleys amongst the mountains of the peninsula, in which water collects and eventually runs off, under the ice, into the sea. Nobody would be any the wiser that it happens, unless it is very carefully and very determinedly studied. Again, it may not even show up on ice radar; unless, maybe, one would be really looking for it.

    Water under ice lubricates it! Whilst an iceshelf could not (relatively) suddenly start moving, if it is locked in between islands, it would certainly create more stresses in the iceshelf which in turn would speed up the breakup; i.e. mostly purely mechanical forces at work.

    I stumbled on your debate only tonight and I didn’t have the time to read it all.
    There was discussion though about the mechanics of the iceshelf breakup; that is what I reckon is behind it. The forces causing the final break-off of an iceberg may not at all be local either. They could be the result from huge seas on the other side of the planet, a constant and gentle residual swell action as it were.
    (Take a bit of fencing wire, and really yank on it; it won’t break. Then try a different method; small movements (a steady as she goes) and, wouldn’t you know it, the wire will first get hot and before long it’ll break. Nice and easy does it!)

    Keep it going – it’s very interesting. Very interesting too that people are actually concerned.

    Cheers,

    Ice Beard

  138. gavin April 14, 2009 at 9:13 am #

    “Both warmth and wave action contribute to breaking up a shelf. But wave action has always been there, and there’s no reason to suppose it’s unusually strong now”.

    IMO, both Nick & Gordon need to consider greater surges under the ice including rising sea levels

  139. david elder April 14, 2009 at 4:26 pm #

    Jen, this has been a fascinating thread on the Wilkins ice shelf and I have learned a lot from it. The following points stood out for me, if I got the story right:

    1. Most of Antarctica has not warmed since the 1970s. Even the recent Steig paper shows this (World Climate Report ‘Antarctica Again’, Jan. 30, 2009). Scant comfort for strong AGW there.

    2. The breakup of the Wilkins ice shelf is being exaggerated according to John McLean (The Wilkins Ice Shelf Con Job: 2 April 2008). McLean sees no clear connection between strong AGW and the ice loss.

    3. There is one small part of Antarctica, the Antarctic Peninsula trailing out towards South America, which does appear to have warmed markedly – some five times the global average. (The Wilkins ice shelf is part of this region.) But an expert on Antarctica, Duncan Wingham, thinks that this warming of the peninsula, and breakup of ice shelves on it, is more likely to be due to ocean currents rather than global warming. The peninsula extends well beyond the bulk of Antarctica and could experience different currents. (The Deniers Part IV. Lawrence Solomon, National Post, 15 December 2006).

    If that is the story, there currently seems to be scant clear-cut evidence for strong AGW in the Antarctic.

    One thing remains unclear to me. I was unable to find much data on the time course of the marked warming of the Antarctic Peninsula. Several posters above tried to help me with this, but I could not seem to find anything really helpful. If anyone knows of any solid and detailed data on this, perhaps they could forward it to Jen for posting on this blog? This was the main loose thread I could see in the story of AGW vs. natural variation in the Antarctic.

    The other loose end was whether volcanic activity was involved in Antarctic ice loss. Debate on this seemed inconclusive.

  140. Jay April 28, 2009 at 1:49 am #

    It’s important to understand the dynamics of ice shelves if you want to have an idea of what this break-up event signifies.

    In any HEALTHY ice shelf, icebergs ALWAYS calve off of it into the sea, while it continues to be fed by ice from the ice sheet or glacier it is attached to (ice sheets and glaciers are fed by snow inland). The concept is simple: ice drops off, only to be replaced by more ice flowing in behind it. Think of an ice shelf like a fingernail if you like.

    However you start to have a PROBLEM when the overall MASS BALANCE of an ice shelf becomes NEGATIVE, which means more ice dropping off and less ice feeding the ice shelf. This has been the case not only of the Wilkins, but also for other ice shelves along the Antarctic Peninsula, such as the Larsen B. The overall MASS BALANCE of ice shelves up and down the AP has been NEGATIVE over the past half century.

    Where WARMING plays a major role is that as the average temperature up and down the Antarctic Peninsula has risen by 2.5°C in the past half century, this has affected rates of precipitation in the area and ultimately the rate at which ice flows out to the ice shelf from the ice sheet, leading to a NEGATIVE BALANCE for many of these ice shelves up and down the AP.

    Thus air or sea temperature at the exact location of calving plays a much less significant role in the overall picture for a given ice shelf. Break-up events have even occurred on the Wilkins during the austral winter (as in July of 2008) — although it’s important not to forget that break-up events have tended to be more pronounced following the austral summer, and seasonal temperature rise would ultimately contribute to undermining the overall stability of such a massive expanse of ice.

    And as for mechanical stress fractures in the ice — these are normal when we’re talking about ice that’s 250 metres thick subjected to the enormous forces of GRAVITY. An ice shelf isn’t going to behave like a tiny melting ice cube, getting round at the edges. The SCALE of mass is different by SEVERAL ORDERS OF MAGNITUDE. Scale is important. Thus GRAVITY plays a significant role when determining how ice in an ice shelf behaves under temperature changes (In order to give you an idea of the significance gravity plays in this situation, keep in mind we’re talking about ice that has flowed to the coast from inland due to the force of gravity — you can look up ‘plastic flow’ if you’re curious to know how gravity makes solid ice flow). As an ice shelf weakens, it’s normal for it to get stress fractures. You can see the stress fractures in the Wilkins in satellite images of it.

    Dr. Angelika Humbert from the University of Münster in Germany would probably be the best person to ask about how stress fractures have formed on the Wilkins, since she’s been studying the Wilkins for years and is one of the best people out there when it comes to ice shelf mechanics. She gave two interviews on the following website, one after the major break-up in March 2008 and one recently after the strip of ice between the two islands disappeared. Perhaps they might be able to give y’all some more information.

    Further reading:

    http://www.polarfoundation.org/www_sciencepoles/index.php?s=2&rs=home&uid=1214

    http://www.polarfoundation.org/www_sciencepoles/index.php?/articles_interviews/angelika_humbert_on_the_future_of_the_wilkins_ice_shelf/&uid=1461

    Here’s a good article from a newspaper called the Christian Science Monitor last year which does a good job of putting things into perspective:

    http://www.csmonitor.com/2008/0328/p25s10-wogi.html

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