64 thoughts on “Volcanos melting W. Antarctica….?”

1. Yes, but global warming is causing the geothermal fluxes…

2. Tom Scharf,
   I think that will be a minority view. Very. Small. Minority.

3. Does anyone really know with any great certainty, how much heat or CO2 is being released by undersea volcanos and what impact that may have on climate or climate change?

   The GCM’s seem to have a lot of uncertainty concerning water, clouds, predicted but non-existent hot spots but do we know anything about what is going on underneath 3/4 of the earth’s surface relative to volcanos or crustal rift zones and the heat they release?

4. I thought this was all well known – glaciers acrete and trap heat which results in basal warming which enables glacier motion.
   When the glaciers move, new glaciation ensues until new heat accumulation results.

   The flux is small:
   http://geophysics.ou.edu/geomechanics/notes/heatflow/q12.gif
   but at glacial time scales, can accumulate.

5. ed,
   The amount of CO2 is probably not enough to matter. But even if it was, we are realeasing CO2 from burning fossil fuels and we know we are releasing a lot.

   CO2 not the issue here. It’s heat from the volcano. I would suspect we do not have a precise estimate of the amount of heat from any volcano — but they likely have bounds in general. In this case, someone has tried to measure the amount of heat from a specific volcano at a specific location. That location happens to be critical to the stability of an ice sheet. No one is suggesting the heat from that volcano is warming the earth generally. Think of “heat under your tea pot”. It does boil the water for tea, but your whole house? not so much. And the neighbors house? Not enough to matter.

6. “Until I read it, my comments are restricted to the prediction of the upcoming blog/twitter storms.”

   The paper is only 2 1/2 pages long excluding the references and the SI is another 2 pages. The paper uses newer sounding data and a different model that results in findings counter to earlier models and associates the higher melting to areas of suspected volcanism. The authors use simulations with added noise to find the water route model that best fits the data. Their results are not all that simple or direct.

   It appears that authors are geophysicists. It will be interesting to see where the inevitable criticisms come – fellow geophysicists or climate scientists. There are at least a few geologists that read at these blogs, although this field might be rather specialized.

7. Mark Brandon has a good post on this paper: http://mallemaroking.org/amundsen-sea-embayment/

8. get paper here:

   http://www.pnas.org/content/early/2014/06/04/1405184111.full.pdf+html

9. sue,
   Thanks, that is a good article.

10. Jack,
    Yeah… I didn’t understand the symbols! Stupid of me.

11. Climate Weenie:

    The flux is small:
    http://geophysics.ou.edu/geomechanics/notes/heatflow/q12.gif
    but at glacial time scales, can accumulate.

    It’s important to note that geothermal heating can measurably influence the rate at which the glaciers creep, and so may need to be included when you model them…even if the main driver for deglaciation is global temperature change:

    That is, your models may not be able to satisfactorily account for the measured rate of ice loss of glacial fields without including geothermal heating effects. This can be true even if the direct ice loss associated with geothermal heating is negligibly small, which is probably the case here.

12. Incidentally, it’s worth noting that glaciers don’t “flow”… the correct rheological term is “creep”. While this probably seems like a minor technicality, words are important, and in this case the difference in words helps explain how a small addition of geothermal heating could have a big effect on the rate at which a glacier creeps.

    For example, the Oxford Reference says:

    The deformation of glacier ice in response to stress, by a process involving slippage within and between ice crystals. The rate of creep is dependent on both stress and temperature. When the shear stress is doubled the strain rate increases eight times, and a rise in temperature from −22°C to 0°C involves a tenfold increase in strain rate.

13. Carrick,

    Yes. I think, given the dynamics of glaciers, you can’t even predict the loss on the ‘ocean’ side away from the volcano because the heat in the volcano region affects the rate of creep toward the ocean and the melt rate is affected by the creep rate. If the glacier did not creep, ice would not be exposed to the warmer water. If it creeps very quickly, the front of the glacier ends up in warm water and melts fast.

    The paper doesn’t really go into that other than to say that understanding the effects of the volcanic heating to predicting the collapse of WAIS.

    So, it’s not entirely clear that merely pointing out that more melting happens near the ocean tells us that acceleration in melting is “due” to warming ocean. But surely that matters too– a warmer ocean will melt ice faster and melting form that end also may affect the creep. (I don’t know enough about glaciers to say for sure.)

14. Lucia:

    But surely that matters too– a warmer ocean will melt ice faster and melting form that end also may affect the creep.

    Well, I’m certainly not an expert on glacier dynamics, but I’m pretty certain that geothermal heating at the interface between the glacier and the underlying bedrock the bottom of a glacier has a much higher efficacy wrt rate of glacial creep than heating from the top associated with modest rises in surface air temperatures.

    My understanding is the bigger effect from global warming on rate of maritime glacier creep is associated loss of material at the terminus of the glacier. Effectively, the loss of material from the glacier terminus increases the average slope seen by the glacier, which directly influences the rate of glacial creep.

    Anyway, Morano’s concept of geophysical heating “causing” glacial glacial ice loss appears incredibly naive. There is a huge distinction between “causing” ice loss and “significantly affecting the rate of loss”.

15. Carrick

    Effectively, the loss of material from the glacier terminus increases the average slope seen by the glacier, which directly influences the rate of glacial creep.

    That’s what I was thinking. It’s the effect on “creep” that matters at both ends.

    Anyway, Morano’s concept of geophysical heating “causing” glacial glacial ice loss appears incredibly naive. There is a huge distinction between “causing” ice loss and “significantly affecting the rate of loss”.

    It that’s what he thinks. I clicked through to find what Morano wrote. As far as I can tell, he linked to a web post using the web posts title. I have little doubt he liked the title, and was happy to have those words used in his post– but Morano in this case (as is often the case) didn’t actually say much about phenomenology.

16. Lucia, I agree. “If that’s what he thinks” is a good qualifier to what I said.

17. Until we can model ice sheet dynamics well enough to understand glacial period termination, I take most of the speculation about the behavior of the Antarctic ice sheets with lots of salt. We know from ice core data that the rate of accumulation of ice at the surface is about an order of magnitude faster during interglacial periods than during glacial periods. If there is currently a net loss of total mass, then it must be due to faster creep and have been similar during previous interglacial periods.

    The rate of increase of Antarctic sea ice area, currently setting new records daily, doesn’t seem to be in complete agreement with warmer water either. Likely it’s some variation on the typical polar seesaw. When it’s warm in the Arctic, it’s cold in the Antarctic and vice versa.

18. Lucia

    ‘So, it’s not entirely clear that merely pointing out that more melting happens near the ocean tells us that acceleration in melting is “due” to warming ocean.’

    It isn’t a question of the “warming ocean”. The warm water that is doing the melting hasn’t been near the surface for many decades, and there is no reason to think that it has been anthropogenically warmed. But there is more of it upwelling and then inflowing under the outflowing glaciers than before. A continent-wide pattern of such increases may have started over a century ago, pointing to a natural cause. (Jenkins et al, 2010, DOI: 10.1038/NGEO890)

19. I went over to the Yale Climate and Media Forum this morning just to post a gloating comment. They had a thread on June 1st with a short video with cameos by Archer, Hansen, Rignot, Alley, and Wagner pushing the idea of ice sheet collapse with Rignot concentrating on the Pine Island and Thwaites glaciers. They judiciously left it to the narrator to mention GW. I commented that no one made any mention of those glaciers being on the ring of fire and I thought it should have been mentioned.
    http://www.yaleclimatemediaforum.org/2014/06/new-video-reports-on-unstoppable-antarctic-glacial-melting/

20. Do not underestimate the ability of volcanic action to have dramatic impacts on glaciers.
    This Antarcitc volcano is obviously a very different type of volcano than the one discussed in the article below, but the point- that volcanos can impact glaciers dramatically- still stands:
    http://hvo.wr.usgs.gov/volcanowatch/archive/2009/09_10_29.html

21. Nic Lewis (Comment #130243)

    Thanks Nic for the comment – I was just going to comment on what you have posted before on this topic. Sometimes these climate phenomena are more complex than we first supoose.

22. “which at least appear to be making fun of the notion that volcanoes are even involved with melting glaciers at all.”
    Justifiably. It’s a scale issue. The Thwaites glacier with catchment is the size of Pennsylvania. Volcanoes aren’t. And they are intermittent.

    This paper doesn’t say volcanoes are melting the glacier. It says there is distributed geothermal heating. And it isn’t much:
    “According to his findings, the minimum average geothermal heat flow beneath Thwaites Glacier is about 100 milliwatts per square meter, with hotspots over 200 milliwatts per square meter. For comparison, the average heat flow of the Earth’s continents is less than 65 milliwatts per square meter.”

    So that’s just maybe double the average you’d get in Illinois, say. Not exactly a volcano. And it’s not going to melt much ice. About a cm/year, in a region where snowfall is probably about 20 cm/yr. And even down there, sunlight averages much more than 0.1 W/m2.

    As Carrick says, the effect is probably lubrication. But 0.065 W/m2 would lubricate too. And as far as modelling goes, we don’t know how slippery the surface is anyway.

23. Nick

    And it’s not going to melt much ice.

    ‘Not melting much’ is not ‘melting none’. And heating causing some melting that causes creep and then induces more is would still be heating that is– ultimately– a cause of melting.

    As Carrick says, the effect is probably lubrication.

    Yes. Lubrication caused by melting a small amount of ice in a specific region. It’s possible to give a nuanced explanation of what’s going on. But a response like “hail mary pass” to an ambiguous statement that is not actually wrong is not “justifyable” in any scientific sense.

24. Lucia,
    “an ambiguous statement”
    The headline was
    “Volcano, Not Global Warming Effects, May be Melting an Antarctic Glacier”
    Not much ambiguity.

25. Nick,
    First I would like to apologize for past snark and less than polite posts. As I have read a lot more of your writing I cannot help but to see that you are patient and polite in your writing and deserve the same in return.
    On the issue of geothermal influences and the reporting there on:
    Did you not say yourself that the water that appears to be undermining the glacier system in question was likely down deep a long, long time ago and could be a completely natural phenomenon? To quote your comment:
    “A continent-wide pattern of such increases may have started over a century ago, pointing to a natural cause. (Jenkins et al, 2010, DOI: 10.1038/NGEO890)”
    That means the headline about the melt not being caused by CO2 would be technically correct. And geoheat/volcanic activity is a significant player.
    And since the evidence is that at least some of the Antarctic glaciers are in fact dynamic enough to have slid off into the oceans over the long view of history, this entire issue points to the idea that once again alarmists have significantly misrepresented the case.

26. Nick–
    Volcanic efficts are melting a portion directly and may be the indirect cause of other melting. And that’s a headline– not a full article. I don’t see it as “more wrong” than a hypothetical headline claiming global warming is melting the glacier.

27. hunter (Comment #130256)

    You are confusing Nick Stokes with Nic Lewis – I think.

28. hunter (Comment #130256)
    Thanks. The quote you’ve attributed to me seems OK, but I don’t recall making it. My main argument about these “natural causes” is this. The geothermal heating and lubrication have probably been around for many millennia, as has the Thwaites Glacier. So what’s different now?

29. Nick Stokes:

    The geothermal heating and lubrication have probably been around for many millennia, as has the Thwaites Glacier. So what’s different now?

    Increased anthropomorphic driving of course.

    If you don’t have geothermal heating correctly incorporated into your model (including its effects on lubrication and elastic creep), you can’t accurately model the response of the glacier to an increase in anthropomorphic driving.

30. Re: Nick Stokes (Jun 10 18:02),

    So what’s different now?

    Indeed. What is different now?

    Ice is a rather good insulator. First year sea ice never gets more than about 2m thick even though the surface temperature is -30°C. The ice sheets in Antarctica are thicker than that and the average temperature is colder. A relatively few decades of relatively small warming shouldn’t be having a substantial effect on the ice sheet dynamics. If the WAIS collapses, it would have done so anyway. Reducing human ghg emissions won’t change the time table significantly, IMO.

31. Also, as for the notion geothermal heating has been around for millenia: actually, who knows? Or at least, who knows how strong it’s been? Volcanic activity waxes and wanes too. Volcanoes become active then go dormant. Activity at the present rate could be the same now as 1000 years ago. It could be less. It could be more. Until someone tries to figure that out and succeeds in nailing the answer down we don’t know.

32. What is clear is that WAI system has come and gone over long periods of time. What seems clear to me is what others have pointed out: hundreds of meters of ice is a pretty good insulator. And warming trends, when the increases still leaves the ‘high’ sub-freezing makes the hype about an Antarctic ice apocalypse pretty silly. No one has offered a mechanism showing:
    – how much warmer the water is in the basement level of the glacier system than in the past (have they shown it in the present?)
    how the water, if it is there, got there.
    This is looking more and more like yet another example in the very long list of examples of cliamte doom hype.

33. Carrick (Comment #130261)

    Carrick, I am sure you meant anthropogenic and not anthropomorphic.

34. lucia (Comment #130263)
    Interesting comment in light of what I heard from Ben Santer at a recent APS conference on climate modeling. He stated that a cause for part of the recent warming pause could be attributed to volcanism for which accounting in aerosols was lacking in conventionally made calculations. If that is the case then much of the historical evidence and estimates for volcanism and climate cooling are also going to contain this uncertainty. Santer was not detailed in his explanation for this lack of accounting, but it sounded as though a number of smaller volcanic events (that would go unnoticed historically) could add significantly to those larger events that are more readily detected. This comment is a bit off topic as it relates to volcanism vis a vis aerosols and not geothermal influence on glaciers.
    I would like to hear more about the current changes Nic Lewis posted about and how much we known with reasonable certainty about these flows. I have read that this upwelling and downwelling of ocean waters at the Antarctica/ocean boundary is a major player in the transport of heat from the low latitudes to the Antarctica. As I recall it is affected by the salinity of the waters involved and would thereby be affected in turn by melt water.

35. Kenneth, thanks. Yes, I really did mean anthropogenic. 😀

36. Kenneth

    Interesting comment in light of what I heard from Ben Santer at a recent APS conference on climate modeling. He stated that a cause for part of the recent warming pause could be attributed to volcanism for which accounting in aerosols was lacking in conventionally made calculations. If that is the case then much of the historical evidence and estimates for volcanism and climate cooling are also going to contain this uncertainty.

    I think the same thing. If volcanic aerosols that were not ‘noticed’ until after they cased the pause that needs ‘splaining were not noticed now and they have sufficient effect to have caused the pause, then the same possibility holds for the entire 20th century and all years prior. For all we “know” the 20th century was ‘distinguished’ by unusually low background vulcanisms leading to enhanced warming as the earth bounced up from the level we would expect ‘normally’. (Also- the opposite could be true. It might be the 20th century had more of these mild non-stratospheric volcanoes. That’s the way uncertainty works.)

    Santer was not detailed in his explanation for this lack of accounting, but it sounded as though a number of smaller volcanic events (that would go unnoticed historically) could add significantly to those larger events that are more readily detected. This comment is a bit off topic as it relates to volcanism vis a vis aerosols and not geothermal influence on glaciers.

    Any discussion of volcanoes is fine here. 🙂

    It seems to me that of course the average level of aerosols should matter. If the skies are unusually ‘clear’ we should see warm spells if unusually ‘masked’ cooler. In a sense, there is a baseline optical depth and an “anomaly” from that baseline. What we see in the ‘explanation’ here is that the modelers do not know the ‘average’ level due to ongoing eruptions which have always happened etc.

    Anyway: in reality,these volcanic eruptions were fairly modest and don’t explain much. But the fact that we are getting “explanations” of “the pause” means that we need to wait a bit of time to determine whether the explanations “worked”. So, for example: if
    (a) the temperature do not ‘recover’ by bouncing up to predicted after the skies manage to clear or
    (b) it turns out the ‘average’ level of vulcanism in the 20th century happened to be exceptionally low and part of the rapid rise during that period was due to accumulated heat during the ‘clear skies’ era

    modelers will have to ‘explain’ something. What they need to explain will differ. But in both cases, it will turn out their projections were too high– but for different reasons.

37. The most recent paper by Susan Solomon’s group at MIT estimates that background volcanic aerosol could account for at most 15% of the pause. Santer is first author. His explanation at APS, if correctly reported, is knowingly wrong. Perhaps misreported or misunderstood. The paper is Santer et.al. Volcanic contributions to decadal changes in troposphere temperature in Nature Geosciences published on line 2/23/2014.

38. Kenneth,
    Your point about anthropomorphic is makes me wonder: I think more and more that the man made climate change we are experiencing is in fact anthropomorphic, and not anthropogenic. We see things changing in the climate and project ourselves onto it to bring a sense of order and perspective. Sort of like what most people think of the various flood myths. The stories claim that the great flood that wiped out the entire world was due to human wickedness. In reality the flood was not worldwide, was at most influenced by where people decided to build and possibly interfere with waterway flows, and the flood did not give a hoot about the victim’s personal lives. Or anything else for that matter.

39. I went back to the link on the APS discussion forum and extracted part of the Santer discussion on volcanic aerosols and the climate warming pause (stasis). I believe my recollections were reasonably representative of what Ben Santer stated.

    http://www.aps.org/policy/statements/upload/climate-seminar-transcript.pdf

    From page 221 of the APS CLIMATE CHANGE STATEMENT REVIEW WORKSHOP with Santer talking:

    “And this was the assumption in CMIP5 that, after Pinatubo, stratospheric aerosol optical depth decayed to zero or to background values by the end of the 20th century. Now, that’s not what happened in the real world. In the real world, there were, as Tim Barnett likes to call it, a swarm of over 17 eruptions with a volcanic explosivity index of three to four after Pinatubo. So, this is an instance of a systematic error in volcanic aerosol forcing. All right, this is now looking in the tropics specifically at stratospheric aerosol depth. Again, vertical lines are eruptions.
    You can see the signatures of these early 21st-century eruptions across the electromagnetic spectrum. So again, we see them in the visible in stratospheric aerosol optical depth. Look at the two largest here, at Tavurvur in Indonesia in 2006, and Nabro in Africa in 2011. You can see that the increase in stratospheric aerosol optical depth leads to this increase in net reflected shortwave at the top of the atmosphere. That backscattering is the primary signature we are picking up here…

    .. Stasis. Anthropogenic changes in greenhouse gases have this slowly evolving tropospheric warming signal which is superimposed on background volcanic cooling. And it’s this juxtaposition of the anthropogenic and volcanic signals that leads to decadal changes in warming rates after El Chichón and Pinatubo.”

40. @Lucia.

    “CO2 not the issue here. It’s heat from the volcano. I would suspect we do not have a precise estimate of the amount of heat from any volcano — but they likely have bounds in general. In this case, someone has tried to measure the amount of heat from a specific volcano at a specific location. That location happens to be critical to the stability of an ice sheet. No one is suggesting the heat from that volcano is warming the earth generally. Think of “heat under your tea pot”. It does boil the water for tea, but your whole house? not so much. And the neighbors house? Not enough to matter.”

    I don’t follow your logic. It’s like saying that if someone who has liver problem, it doesn’t matter if they drink, since they had a problem anyway.

41. bugs,
    I”m not sure what your analogy is supposed to tell us nor why you think it is “like” what I am saying in my response to someone who is suggesting CO2 emmitted by volcanoes might be the cause of global warming.

    (1) The CO2 emitted by the volcano under the glacier isn’t causing any local melting. This is because CO2 doesn’t cause melting directly, heat does.

    (2) But even beyond that, the CO2 from volcanoes is not the prime cause of the increased CO2 in the atmosphere since the industrial revolution began. That increase is caused by man.

    I”m a little surprised you would be posting something that would suggest otherwise. If your point is that CO2 might be lower than it is if we could just turn volcanoes “off”– maybe. But that is a natural factor that existed both before and after the beginning of the industrial revolution and there is no indication to suggest the current increase in CO2 was ’caused’ by volcanoes suddenly spewing much, much more CO2 into the atmosphere. (In anycase, we likely can’t turn them ‘off’.)

42. Kenneth Fritsch,
    Santer’s arm waving and post hoc rationalization is a good example of man made global warming.

43. Logically I am not sure if Carrick and Lucia have the glacier by the horns rather than the tail.
    A glacier is built up by ice formation on a slope, higher the colder, which the extends down to the valley, then along the valley.
    The only effect of elevation that matters is from the head of the glacier to its lowest point.
    Unlike water which would maintain a near level surface more ice is built up at elevated, colder areas closer to the glacier origin.
    The rate of flow is totally dependent on the height and mass of the glacier at its origin, not its end.
    It can never flow faster as it gets smaller as it has less mass to cause it to flow.
    The end of the glacier may well retreat in hotter weather but this does not mean the glacier is flowing faster. In terms of what happens when it meets the sea, the temperature of the water is not important.
    When enough glacial mass accreted the glacier will calve.
    One would expect bigger more massive calving events with bigger colder glaciers once they extend to far into the sea.
    Carrick?

44. Lucia, the amount of CO2 produced by volcanoes is not negligible but poorly estimated and goes into the sea much more than the atmosphere ( most volcanoes are under the sea and do not vent to the atmosphere).
    Most of the 400 ppm is produced by decomposing vegetation and bacteria in the sea and under the earth surface. The amount from volcanoes and other subsurface heat related CO2 formation is regular and as important as human contribution and we can stop neither unless we stop human civilisation.
    And every year most of it is absorbed and another whole new lot is produced despite claims of long lived CO2 , that amount is vanishingly small.

45. Science of doom put up a prescient post on ice sheet models on 14/4/2014 where he commented that geothermal energy of 0.1 w/m2 was one of the two causes of basal sliding which works over thousands of years as it is so small.

46. Re: angech (Jun 14 00:38),

    CO2 released from the crust is considered to be in balance with CO2 lost to the crust from weathering and subduction. The rate is small, though, compared to emissions from burning fossil fuel, cement production and land use/land cover changes.

    The lifetime of an individual molecule of CO2 in the atmosphere may be short, on the order of 5 years because of the large seasonal fluxes into and out of the biosphere as well as large, relatively constant fluxes into and out of the oceans, but that doesn’t mean that the concentration of CO2 changes as rapidly. Ferdinand Englebeen (Section 7 here ) has a good analogy of why the equilibration time of CO2 in the atmosphere is much longer than the lifetime of an individual molecule of CO2. A chemical engineer would understand if you referred to the atmosphere as a continuous flow stirred reactor.

47. hunter (Comment #130315)

    Of all the participants in this forum, Ben Santer was near unique in often stating that “we known x with certainty” or words to that effect.

    Issac Held, who I thought was more laid back in making definitive statements about climate and climate change, invoked his 20 plus years working on climate models and was very emphatic about GHG forced temperature changes being linear over time- or at least as I understood what he was saying.

    What impressed me about these discussions was that in such a forum with a back and forth on the evidence put forth by the more and less skeptical participants is the uncertainty of that evidence. Key to me was Judith Curry’s position on the importance of establishing and acknowledging more objective uncertainty limits on a number of climate change variables.

48. angech, what you gave above seems to be an overly simplistic description.

    You might want to review this before trying to argue that mean inclination angle does not affect the rate of glacier creep.

    This seems apropos (emphasis mine):

    Causes and consequences of variations in the velocity of glacier flow

    Rates of ice movement vary enormously from one glacier to another, but generally lies in the range 3 to 300ma-1. Glacial velocity depends on a number of factors;
    • thickness: a glacier moves because pressure generated by its own weight causes it to deform and/or slide, consequently, thick glaciers often flow faster than thinner glaciers. This also explains why high velocity glaciers tend to occur in areas of high snowfall.
    • temperature: in general, temperate and polythermal glaciers flow at greater velocities than polar glaciers. This is because temperate and polythermal glacial ice is warmer and is therefore able to deform more easily and, further, the presence of meltwater at their base promotes basal sliding.
    • bedrock: more rapid movement occurs over easily deformable rock, such as clay or shale, because bedrock deformation increases the rate of basal sliding. Greater velocities also occur over impermeable rock surfaces as compared to permeable since the percolation of meltwater into permeable rock masses will reduce lubrication at the ice/rock interface and retard flow.
    • gradient: glaciers with steep surface gradient flow faster than those with more gentle gradients, since the former are affected by greater gravitational forces.

    What I was arguing above was that if the ablation region for a maritime glacier (or that of any glacier emptying into a nearly horizontal basin) is decreased, that results in an increase in the mean slope of the glacier, which in turn results in a faster rate of glacier motion.

49. Kenneth Fritsch,
    It seems to me that only dangerous manmade global warming we are experiencing is anthropomorphic, not anthropogenic.
    Santer, Trenberth, Mann, Gore, etc. have not so much identified a human caused crisis in the climate. It is rather that they have imprinted humans into the climate. They have met the enemy and it is their projected bogeyman.

50. hunter, don’t entirely agree with you, but that is cleverly put!

51. Carrick, I come into these discussions on a steep learning curve and with a hindrance in my flow rate of taking up ideas due to the bias I came in with.
    I was giving a simple but not simplistic view of glaciers asking if the mechanism of formation and development is as outlined then people arguing that faster flow is a sign of warming are wrong as faster flow is more likely to be associated with a bigger colder taller higher glacier than with the remnant of one if warming was taking place.
    Is this basically correct?
    Your point about loss at the end increasing the slope hence speed may be technically correct but the whole reason for the loss (calving) of a sea glacier is that the glacier is expanding ,growing , increasing in size and pushing that extra bit into the sea where stress fractures develop and it shears off. Consequent of the loss of that obstructing bit of ice and the frictional forces it had inherent in it the remainder of the glacier may well move forward slightly faster.
    But this is a physical not a warming cause

52. Temperate and poly thermal glaciers
    Yes to the second but no to the first.
    Thanks for all the other correct stuff but that is not what I am asking you to consider.
    A temperate glacier should in theory if it is the same size shape and height as one in a cold climate be at the same surrounding temperature where the glacier is.
    You do not get glaciers in the flat Sahara desert. If you go up in elevation you get colder and a surviving glacier of the same size should have the same surrounding temperature, otherwise it would not stay at the same size
    SOD says that a glacier is 6 degrees colder on top for every kilometre of height. A similar glacier in the Swiss alps would be the same as a glacier on a flat part of Norway for example in surrounding temp

53. Carrick,
    Thanks. The distinction between anthropogenic is and anthropomorphic is really big but rather subtle.

54. Anthropophobic?

55. Nick Stokes,
    Anthropophobic- that is a new one. The pathological fear of people or human company. A lot to consider in that noun.
    When our ancestors anthropomorphized weather, we got the great flood stories, how a great flood of the long ago past was God’s judgement, and how God promised that a humanity destroying flood would never happen again.
    This modern bit of anthropomorphizing seems positively misanthropic.

56. How ’bout anthroporcinic?

    As in anthroporcine – climate epoch marked by a mad rush by a segment of the “STEM community” for tax-payer funds. Alternative spelling: anthroporcene.

    And then there’s anthropornetic climate change…

57. “Sea level as a stabilizing factor for marine-ice-sheet grounding lines” (Gomez et al, Nature 2010) pdf http://www.people.fas.harvard.edu/~phuybers/Doc/stabilizing_naturegeo2010.pdf

    points out that isostasy can be an important countervailing (negative) feeedback against Thwaites-type “collapse”.

    The Thwaites glacier in Antarctica is presently grounded on a sill (relatively shallow). As the glacier recedes, it would ground at deeper depths. This change in grounding depth would exacerbate the volume of recession.

    Gomez and coauthors observe that glacier recession would also result in uplift offshore. Any uplift would partly offset the increase in grounding depth. Gomez and coauthors seem to think that the effect could be material.

    Though generally overlooked, glacial isostasy (from the past LGM) is still an important factor in relative sea level rise on the US East Coast ( 50% or so in some locations).

    As an aside, people worried about the Thwaites glacier seem to take the position that the changes in grounding depth are irreversible even over a millennium. However, if it turned out to be a big risk for sea level rise, surely people would turn their minds to whether it was possible to reinforce the sill so that the grounding depth was held more or less constant as the glacier receded. I have no idea whether it is possible or feasible, but it is not necessarily less fantastical than many concepts and policies.

58. “Anthrosquiggilianism”

    Human beings drawing squiggly lines and pretending they mean something.

    Andrew

59. Anthrosquigglianism,

    Good God, Andrew. If you’re going to invent a word, at least spell it right.

60. Andrew_KY & j ferguson,
    +1
    Anthrosquiggliansim is a species of anthropomorphism, I think.
    Anthroporcine is definitely a species of anthropogenic- people turning themselves into Orwellian pigs from “Animal Farm”.

61. Many who are anthropophobic are also anthracophobic!

62. How about: We live in the ‘hominisodiumicine’.

63. RobWansbeck,
    Yes, there does appear to be an irrational fear of coal growing out of the anthropomorphic obsession regarding climate.
    lol.

64. SteveF,
    Woh. That sums up this age rather darkly.

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