Glacier loss in Hawaii tied to change in North Atlantic AMOC current

Mauna Kea glacial deposits Gray rubble on the flanks of Mauna Kea on the island of Hawaii lie in contrast to the red volcanic rock behind them, and were deposited by a glacier that disappeared thousands of years ago. (Photo courtesy of Oregon State University)

From an Oregon State University press release:

Ancient Hawaiian glaciers reveal clues to global climate impacts

CORVALLIS, Ore. – Boulders deposited by an ancient glacier that once covered the summit of Mauna Kea on the island of Hawaii have provided more evidence of the extraordinary power and reach of global  change, particularly the slowdown of a North Atlantic Ocean current system that could happen again and continues to be a concern to climate scientists.

A new study has found geochemical clues near the summit of Mauna Kea that tell a story of ancient glacier formation, the influence of the most recent ice age, more frequent major storms in Hawaii, and the impact of a distant climatic event that changed much of the world.

The research was published in Earth and Planetary Science Letters by scientists from Oregon State University, the Woods Hole Oceanographic Institution, University of British Columbia and U.S. Geological Survey. The work was supported by the National Science Foundation.

“Mauna Kea had a large glacial ice cap of about 70 square kilometers until 14,500 years ago, which has now all disappeared,” said Peter Clark, a professor of geosciences at OSU. “We’ve been able to use new data to determine specifically when, where and most likely why the glacier existed and then disappeared.”

Mauna Kea, at 13,803 feet above sea level, is in a sense the tallest mountain in the world because it rises 30,000 feet from the sea floor. Dormant for thousands of years, it once featured a large glacier on its massive peak at the height of the last ice age about 21,000 years ago. As the ice age ended and the global climate warmed, the glacier began to disappear.

photo

Peter Clark, a professor of geosciences at Oregon State University, stands in a field of glacial debris on the mountain of Mauna Kea in Hawaii, left there by an ancient glacier. (Photo courtesy of Oregon State University)

However, the new research found that the glacier on Mauna Kea began to re-advance to almost its ice age size about 15,400 years ago. That coincides almost exactly with a major slowdown of what scientists call the Atlantic meridional overturning circulation, or AMOC, in the North Atlantic Ocean.

The AMOC is part of a global ocean circulation system that carries heat from the tropics to the North Atlantic. This transported heat is the primary reason that much of Europe is warmer in the winter than would be expected, given the latitude of the continent.

Studies of past climate change indicate that the AMOC has slowed a number of times, in surprisingly short periods, causing substantial cooling of Europe. Because of that, the potential future decline of the current is of considerable interest.

But scientists have found that the AMOC does more than just keep northern Europe habitable. Its effects can extend far beyond that.

“The new data from Mauna Kea, along with other findings from geological archives preserved in oceans and lakes in many other areas, show that the decline of the AMOC basically caused climate changes all over the world,” Clark said. “These connections are pretty remarkable, a current pattern in the North Atlantic affecting glacier development thousands of miles away in the Hawaiian Islands.

“The global impact of the AMOC changes,” Clark added, “was just massive.”

The formation, size and movement of glaciers can provide valuable data, he said, because these characteristics reflect current and historic changes in temperature, precipitation or both.

The study concludes that the growth of the Mauna Kea glacier caused by the AMOC current changes was a result of both colder conditions and a huge increase of precipitation on Mauna Kea – triple that of the present – that scientists believe may have been caused by more frequent cyclonic storm events hitting the Hawaiian Islands from the north.

The findings were supported by measurements of an isotope of helium being produced in boulders left by the Mauna Kea glacier thousands of years ago. The amount of this helium isotope reveals when the boulders were finally uncovered by ice and exposed to the atmosphere.

The deposits containing the boulders are the only record of glaciation in the northern subtropical Pacific Ocean. Nearby Mauna Loa probably also was glaciated, but evidence of its glaciation has since been destroyed by volcanic eruptions.

The study by Clark and colleagues provides additional evidence that rapid changes in the AMOC can trigger widespread global change. Some past abrupt decreases in the AMOC have been linked to an increase of freshwater flowing off the continents into the North Atlantic.

The potential under global warming for increases in freshwater from melting ice and changes in precipitation patterns have heightened concerns about the AMOC and related climate effects in the future, researchers said.

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58 thoughts on “Glacier loss in Hawaii tied to change in North Atlantic AMOC current

  1. It is my understanding that there are 11 “tubes” within the AMOC and that recently it was shown that only 2 of the “tubes” are “pumping” and sluggish at that. Do you have any current information? It may prove interesting if there was a total shut-down AMOC and the resulting cooling. It just might counter balance some of the climate change we are just beginning to see.

  2. Why must they always have that final paragraph about “global warming”? It seems somehow obligatory.

  3. Yet more solid proof, based on getting away from the computer and researching the facts, that the climate has been in flux for aeons. Thank you.

  4. The potential under global warming for increases in freshwater from melting ice and changes in precipitation patterns have heightened concerns about the AMOC and related climate effects in the future, researchers said.
    So the tactics are changing: “global warming” leads to “global freezing”.
    The key to performing this “switch” is based upon getting people to accept that man is responsible for raising CO2 levels (hence the current onslaught of bogus CO2 papers).
    Once this is achieved “they” can suddenly discover a new/refined feedback mechanism that changes the CO2 feedback to be either positive (when it is heating) or negative (when it is cooling)… either way they are trying to cook the books… either way it is your fault… either way you pay the price!

  5. Surprising that Oregon State University is surprised. The North Atlantic is the major heat supplier of the Northern Hemisphere during the winter season, reaching the latitude of 80°North, much less the Northern Pacific (Aleutian) going up to about 55°North. There was a recent global cooling for three decades that commenced with WWII since 1940. For a couple of years the North Atlantic and the Western Pacific had been naval warfare battle ground, which may have contributed to the downward trend, details at: http://www.oceanclimate.de/;
    http://climate-ocean.com/:
    What did H.H. Lamb say in 1976?
    ___“The workings of the ocean have been too little considered in most text on climatology”. To little has change, although also H.U. Sverdrup advised three decades years earlier:
    _____“….one cannot deal independently with the atmosphere or the oceans, but must deal with the complete system, atmosphere-oceans. This fact has been recognized in oceanography, where one gets nowhere by neglecting the relation to the atmosphere, but in meteorology it has not yet received sufficient attention.” (H.U. Sverdrup, 1942, “Oceanography for Meteorologists”, New York, 1942, Chapter X, p. 223

  6. So this is what will happen to Hawaii when the global cooling starts.
    Have a little glacier with your lava.

  7. So, have I got this right….Warming might cause greater melting of ice/permafrost/whatever. The resulting injection of freshwater into Northern waters results in a slowdown of the AMOC. That in turn could result in cooling in lower latitudes (glaciers on Mauna Kea etc).
    Is that a self-regulating climate feedback system?

  8. Question from an “ignorant bystander” how does a cooling mechanism cause more fresh water run off? Surely it was locked up in the growing ice fields postulated in this article?

  9. The picture of the idiot standing in the glacial field has me deeply concerned. One of the main features of glacial rock is smooth edges and fine dust. These look very angular, perhaps too angular. Proof for the existence of glaciers relies on landscape features such as valleys, rounded rocks, displaced boulders and large quantities of moraine. Don’t see it here. Perhaps it’s elsewhere on the island.

  10. “Some past abrupt decreases in the AMOC have been linked to an increase of freshwater flowing off the continents into the North Atlantic.”
    Anyone have some references for this?

  11. rbateman says: August 6, 2010 at 1:25 am
    So this is what will happen to Hawaii when the global cooling starts.
    Have a little glacier with your lava.

    Icelanders alone can’t have all the pleasures all the time.

  12. Neil. The freshwater influx WAS the cooling mechanism. When the huge North American meltwater lake broke through and drained into the North Atlantic, it’s lower density formed a barrier to the warm waters of the gulf stream and diluted the salinity of the deeper returning flow, shutting off the ability of the cooling stream to drop down into the return “pipe.”

  13. Friar said: “The resulting injection of freshwater into Northern waters results in a slowdown of the AMOC.”
    From the sea ice discussion threads, I thought it was the lack of refreezing that slows down the AMOC. It wouldn’t surprise me that too much Arctic ice would ultimately slow down the AMOC since there would be no open water to freeze or thin ice to grow thicker. Without newly frozen ice, there is no source of dense salty water to sink and kick off the circulation.

  14. “There was a recent global cooling for three decades that commenced with WWII since 1940. For a couple of years the North Atlantic and the Western Pacific had been naval warfare battle ground, which may have contributed to the downward trend…”
    Well…the cooling that started in the 1940s also was when the PDO went negative which, BTW, it has done again recently. I’d be more willing to believe the climate shift was due to a widespread temp swing in the largest ocean rather than a few ships steaming around…ya’know?

  15. Must be something wrong with either the science or the press release. That readvance they are talking about must be the Yonger Dryas Stadial which maybe (but far from certainly) was caused by a slowdown in AMOC. However that started about 12,800 years ago, not 15,400. At about 15,000 there was instead major warming and meltback of glaciers.

  16. Given the lack of anthropogenic CO2 being pumped into the atmosphere 16 odd thousand years ago, what triggered the last AMOC event and what proof exists that the next event will be any different?

  17. “Some past abrupt decreases in the AMOC have been linked to an increase of freshwater flowing off the continents into the North Atlantic.”
    Could they possibly be referring to the Younger Dryas? There were completely different circumstances then – mile-high ice sheets melting, creating a gigantic lake which then burst through an ice dam, flooding into the north Atlantic.
    They seem to just keep recycling the same old ridiculous CAGW/CC scares.

  18. stephen richards says:
    August 6, 2010 at 2:50 am

    My thoughts too.
    Maybe it was just a névé, a patch of permanent snow/ice with no flow. Glaciers in Iceland with nearby lava have reduced the lava to black sand by repeated freeze/thaw cycles.

  19. stephen richards says:
    August 6, 2010 at 2:50 am

    One of the main features of glacial rock is smooth edges and fine dust. These look very angular, perhaps too angular. Proof for the existence of glaciers relies on landscape features such as valleys, rounded rocks, displaced boulders and large quantities of moraine. Don’t see it here. Perhaps it’s elsewhere on the island.

    Smooth edges come from wear as the rocks are transported. These are near the mountain top and weren’t transported very far. Given the whole island is a volcano, glacial erratics (I assume that what you meant by displaced boulders) would be hard to identify. Large quantities of moraine – check. The photos don’t show a terminal moraine, that happens at the glacial face where debris is pushed or dropped off as the front melts. Cape Cod and the nearby islands are one of the best examples of terminal moraines. When you say valleys, I assume you mean U shaped valleys and hanging valleys, both require a long period of glaciation to dig out the U shape, I’d guess these photos are too high and, the glaciers never large enough, and didn’t have time.
    The best examples of those I’ve seen were on my first long bicycle tour. The lower stretch of the Skagit River in Washington State on Rt 20 is a broad U shape, and I saw a waterfall or two on the far wall from a V shaped valley that fed into the excavated space. The upper reaches are also great, and at bicycle speed there’s lots of time to consider what you’re seeing. And stop for yet another photo.

  20. crosspatch says, August 6, 2010 at 12:16 am: Why must they always have that final paragraph about “global warming”? It seems somehow obligatory.
    That is what’s known within the science community as “The Money Shot.”

  21. “However, the new research found that the glacier on Mauna Kea began to re-advance to almost its ice age size about 15,400 years ago”
    This is quite misleading, since 15400 years ago was still well within the last glaciation (and the Laurentide ice sheet was still immense).

  22. Do I detect a certain level of arrogance amongst the northern hemisphere ocean and atmospheric science establishment.
    Any climate altering episode of any consequence of the past apparently starts somewhere in the North Atlantic Ocean or in regions abutting Europe and / or North America.
    The world is a damn sight bigger place than that and the North Atlantic although a large ocean is far from being the biggest ocean and I would suggest out of all the oceans of the world it quite likely that it is not the most important ocean from the global climate perspective.
    As the southern hemisphere’s relatively unknown Great Southern Ocean is the only ocean that links to all of the world’s ocean basins, any ocean link effects that occur between oceans must at some time have passed through the Southern Ocean and would be modified and altered and changed by the conditions that exist in the Southern Ocean.
    Then we have the immense South Pacific Ocean with the world’s largest ocean currents, many still relatively little known and and even less researched which are almost a completely unknown quantity in their short and long term influences on the global climate.
    From here in Australia I see a certain level of hubris from the northern hemisphere researchers that is warping the past and present ocean climate science with their North Atlantic centric view of the origin of the major climate changing influences.

  23. # JKrob says: August 6, 2010 at 3:21 am
    __”Well…the cooling that started in the 1940s ……a few ships steaming around…ya’know? “ RE to: ArndB says: August 6, 2010 at 12:59 am
    Ya’know, naval war during WWII is not only about many thousand ships, shelling each other once and a while, but many millions, if not billions of explosions below the sea surface, due to shelling, bombing, depth charges, torpedoes, sea mining and so on. What needs to be explained:
    ___why Europe experienced three extreme winters, 1939/40, 1940/41 and 1941/42,
    ___why SST and air temperature decreased globally when naval war covered the entire North Atlantic since Pearl Harbor, December 1941; and
    ___why Japan got the coldest winter on record 1944/45 when US Pacific Fleet battled with a huge armada in the Western Pacific when closing in on the enemy during 1944 ( discussed at: http://www.what-is-climate.com ).
    All questions are poorly understood, even 65 years after WWII has ended. No reasonable explanation is given why it happeed. What the press release of Oregon State University indicates, could presumably be understood since long, if the massive interference in the marine environment from 1939 –1945 had been thoroughly investigated. Even a minor contribution by naval war should be know.

  24. From now on I will be known as “global change” ??
    as in “have provided more evidence of the extraordinary power and reach of global change “

  25. I think they have a point!
    Well, maybe it’s not a very big point, but it is a point.
    Definition – “a geometric element that has position but no extension; ‘a point is defined by its coordinates’ ”
    Be happy that we are not experiencing the problems today that our forebearers had to endure 11,600 years ago (or before). Global Warming is NOT a myth. The real question is – ‘Who, or better still, What causes it?’ Oh! Yes, there is the other side of the coin too. Global Cooling is NOT a myth either!
    http://i43.tinypic.com/1zoanbc.jpg

  26. ArndB says:
    “No reasonable explanation is given why it happened”
    Why not natural variation, say the ENSO warm cycle cycle ending? No need to blame it on humans.

  27. This is my favorite glacier picture that proves climate changes, even w/o the hand of man.
    https://docs.google.com/leaf?id=0B5vbWLK5dTl2NWQzYzNkOGMtMDg0Yi00MWRmLTk5MTMtNTczMGU5YjU0NDdj&hl=en
    The picture caption tells the story of the drastic climate change that the earth has experienced throughout its’ history.
    Also, read any of the book by Brian Fagan.
    http://www.amazon.com/Brian-M.-Fagan/e/B000AR7W0O/ref=sr_ntt_srch_lnk_1?_encoding=UTF8&qid=1281100890&sr=8-1

  28. ArndB says:
    August 6, 2010 at 5:13 am
    ArndB,
    There wast not constant major fighting either in the Atlantic or Pacific all the time. Long lulls between Guadalcanal/Wake/Saipan&Guam/Iwo Jima & Okinava etc. and only major naval effort in North Atlantic was Normandy Invasion in June 44. Most of the rest was sporadic localised confrontations even in the Med. I doubt very much if the sum of military activity could have had a major cooling influence. Think of all the heat generated by the explosions and burning of fuel to offset any cooling. In fact, on balance I would have thought that WW2 would have caused more heating that cooling, but it is a moot point if it would have affected the climate at that time

  29. When the last Ice Age ended, glaciers receded all over the world. Including the ice caps, two miles thick, which covered much of Canada (and Scandanavia and beyond).
    Why is it a story that a glacier disappeared on Hawaii at the same time, when the earth got so much warmer emerging from the Ice Age? Where better to disappear??
    My reading is that during the last Ice Age, there was a turning on and off of the Thermohaline Circulation, the older name for what the author now calls the AMOC.
    But my reading also tells me that it is very minor factor during the interglacial we are now in (the Holocene), and that it is the jet stream, diverted south by the Rocky mountains, which as a result of the diversion is headed north by the time it nears Europe, bearing warm winds with it. Put differently, if the Gulf Stream stopped, it would have a minor effect on the European climate today. If the jet stream stopped bringing warm air, it would have a major effect today in cooling Europe.
    Here is a link for this particular little nugget of science:
    http://www.americanscientist.org/template/AssetDetail/assetid/51963;jsessionid=baadngVM-2ipB0?fulltext=true
    Here is the title and author’s name, and the last three paragraphs of this article:
    “The Source of Europe’s Mild Climate
    The notion that the Gulf Stream is responsible for keeping Europe anomalously warm turns out to be a myth
    Richard Seager
    …..The Longevity of a Legend
    When Battisti and I had finished our study of the influence of the Gulf Stream, we were left with a certain sense of deflation: Pretty much everything we had found could have been concluded on the basis of results that were already available. Ngar-Cheung Lau of the National Atmospheric and Oceanic Administration’s Geophysical Fluid Dynamics Laboratory (GFDL) and Princeton University had published in 1979 an observational study in which he quantitatively demonstrated the warming and cooling effects that large-scale waves in the atmosphere had in Europe and eastern North America, respectively. In the 1980s, atmosphere modelers such as Brian J. Hoskins and Paul J. Valdes at the University of Reading in England and Isaac M. Held and Sumant Nigam at GFDL had shown how such stationary waves, including those forced by mountains, warm western Europe. In the late 1980s, two other GFDL researchers, Syukuro Manabe and Ronald J. Stouffer, had used a coupled ocean-atmosphere climate model to determine the climate impacts of an imposed shutdown of the North Atlantic thermohaline circulation. Their modeled climate cooled by a few degrees on both sides of the Atlantic and left the much larger difference in temperature across the ocean unchanged. Other published model experiments went on to show the same thing. Further, the distinction between maritime and continental climates had been a standard of climatology for decades, even centuries. What is more, by the late 1990s satellite data, and analyses of numerical models into which those data had been assimilated as part of the weather-forecasting process, had shown that in mid-latitudes the poleward transport of heat by the atmosphere exceeds that by the ocean several-fold.
    All Battisti and I did was put these pieces of evidence together and add in a few more illustrative numerical experiments. Why hadn’t anyone done that before? Why had these collective studies not already led to the demise of claims in the media and scientific papers alike that the Gulf Stream keeps Europe’s climate just this side of glaciation? It seems this particular myth has grown to such a massive size that it exerts a great deal of pull on the minds of otherwise discerning people.
    This is not just an academic issue. The play that the doomsday scenario has gotten in the media—even from seemingly reputable outlets such as the British Broadcasting Corporation—could be dismissed as attention-grabbing sensationalism. But at root, it is the ignorance of how regional climates are determined that allows this misinformation to gain such traction. Maury [NOTE: Maury is the originator of the idea that the Gulf Stream keeps Europe warm, from 1855.] should not be faulted; he could hardly have known better. The blame lies with modern-day climate scientists who either continue to promulgate the Gulf Stream-climate myth or who decline to clarify the relative roles of atmosphere and ocean in determining European climate. This abdication of responsibility leaves decades of folk wisdom unchallenged, still dominating the front pages, airwaves and Internet, ensuring that a well-worn piece of climatological nonsense will be passed down to yet another generation.”
    So the tie in for the warming in today’s article doesn’t make sense during our current interglacial. A larger point is that when the science media is mostly scientifically illiterate, and doesn’t know their subject, the demise of the AMOC and the Gulf Stream and the main cause of Europe’s warmth never gets known by the public. This is not the first time, is it?

  30. A follow up to the demise of the idea that the Gulf Stream is the major source of warming for Northern Europe. Here is the link for the Columbia Lamont-Doherty Earth Observatory press release on the study summarized in the previous comment:
    http://www.earthinstitute.columbia.edu/news/2002/story09-27-02.html
    FYI, and not to get people upset, but the Lamont-Doherty Earth Observatory is very mainstream when it comes to climate research, so these findings are anything but from “contrarians.”

  31. Cause and Effect! Just because you have a collection of effects does not means they have the same cause or that the causes are related. “Occuring at the same time” does not have to mean “caused by the same thing”. The ringing of my doorbell does not cause people to appear at my front door ( I’ve had this conversation with my dog several times). This is where the hard, boring work of science sifts through the evidence to coax out the results. Some times it is easy, some time you have to say “I don’t know” and another generation may be able to find the answer.

  32. stephen richards says:
    August 6, 2010 at 2:50 am
    The picture of the idiot standing in the glacial field has me deeply concerned. One of the main features of glacial rock is smooth edges and fine dust. These look very angular, perhaps too angular. Proof for the existence of glaciers relies on landscape features such as valleys, rounded rocks, displaced boulders and large quantities of moraine. Don’t see it here. Perhaps it’s elsewhere on the island.
    —————
    Gratuitous incivility and flaunting one’s own ignorance are better done orally than with a keyboard.

  33. crosspatch
    August 6, 2010 at 12:16 am
    “Why must they always have that final paragraph about “global warming”? It seems somehow obligatory.”
    It is, and I am not being facetious when I state that. I call it the obligatory moonbat line. Read any NASA press release. The lefties do it with writings on other subjects as well. Its standard propagandist practice.

  34. Jeff (of Colorado) says:
    August 6, 2010 at 6:53 am
    “Cause and Effect! Just because you have a collection of effects does not means they have the same cause or that the causes are related. “Occuring at the same time” does not have to mean “caused by the same thing”.”
    Although I agree generally with this statement, let us not be too slavish in bowing to this incantation. After all, no small amount of scientific discovery arose from observations of coincident phenomena. I would dare to say, without it, there probably would have been little scientific discovery ….. ocean and earth tides- the position of the moon …. apples, pears and cannon balls falling toward earth…. surely if two seemingly unrelated observations repeat in time (coincident or lagged) they are good candidates for investigation as cause and effect, or two effects of some other cause or…. Like a lot of cautionary tales they are not intended to divert us away from seeking a relation.

  35. Ed_B says: August 6, 2010 at 5:59 am
    ___”Why not natural variation, …..No need to blame it on humans.”
    What is ‘natural variation’ in this respect? A synonym for: we do not know? The ocean works according the laws of physic.
    And what is the climate change debate all about? Does human change climate? No effort should be spared to know how human activities may change atmospheric processes, and the ocean is the dominant player in the game.

  36. # John Peter says: August 6, 2010 at 6:23 am
    __A__”In fact, on balance I would have thought that WW2 would have caused more heating that cooling,..”
    __B__” There was not constant major fighting…”
    __C__”…Normandy Invasion in June 44…
    __D__”… confrontations even in the Med..”
    Reply A: The average temperature of the ocean is mere 4°C.
    Reply B: Any disturbance at a sea locality may continue to ‘exist’ for a long period of time.
    Reply C: What about “ A Storm from nowhere few days after D-Day in June 1944
    The worst storm in 40 years and meteorology is silent.”; discussed at: http://www.what-is-climate.com/Archiv/april_10.html
    Reply D: The Mediterranean Sea is a very special case for many reasons, and the sea water is nowhere below 10°C even in 3500 meters depth.
    Admittedly, linking the global naval warfare to the global cooling from about 1940 to the 1970s is a long way to go. That is much more promising with regard to the three extreme war winters in Europe, when the North and Baltic Sea were forced to release the store heat more quickly during the autumn than usually.

  37. A Large Drop in Atmospheric 14C/12C and Reduced Melting in the Younger Dryas, Documented with 230Th Ages of Corals
    ABSTRACT:
    “Paired carbon-14 (14C) and thorium-230(230Th) ages were determined on fossil corals from the Huon Peninsula, Papua New Guinea. The ages were used to calibrate part of the 14C time scale and to estimate rates of sea-level rise during the last deglaciation. An abrupt offset between the 14C and 230Th ages suggests that the atmospheric 14C/12C ratio dropped by 15 percent during the latter part of and after the Younger Dryas (YD). This prominent drop coincides with greatly reduced rates of sea-level rise. Reduction of melting because of cooler conditions during the YD may have caused an increase in the rate of ocean ventilation, which caused the atmospheric 14C/12C ratio to fall. The record of sea-level rise also shows that globally averaged rates of melting were relatively high at the beginning of the YD. Thus, these measurements satisfy one of the conditions required by the hypothesis that the diversion of meltwater from the Mississippi to the St. Lawrence River triggered the YD event. http://www.sciencemag.org/cgi/content/abstract/260/5110/962?ijkey=44f772b6ea27476f0ae99b0928fc909eb45c2ac7&keytype2=tf_ipsecsha

  38. Re Richards, et al. above – Serious grinding of carried boulders by glaciers implies a serious bedrock against which to grind.
    The lavas I’ve seen in Hawaii are the lamest excuse for lava ever, more likely to be grindee than grinder. Any real rock like basalt riding down on a glacier above it would just erode the underneath with little effect on the carried stones.
    Disclaimer: not a geologist, just an observer

  39. John says:
    August 6, 2010 at 6:29 am
    “A follow up to the demise of the idea that the Gulf Stream is the major source of warming for Northern Europe. Here is the link for the Columbia Lamont-Doherty Earth Observatory press release on the study summarized in the previous comment:
    http://www.earthinstitute.columbia.edu/news/2002/story09-27-02.html
    FYI, and not to get people upset, but the Lamont-Doherty Earth Observatory is very mainstream when it comes to climate research, so these findings are anything but from “contrarians.”

    I also think that a slow gulf stream would have little immediate effect on Europe, but would probably have an instant effect on the Arctic. Then after a few years a colder Arctic would definitely effect European temperatures. Climate is an interlocking system and all parts of the chain need to be considered. Because of the deterministic chaos inherent in our weather/climate system, these links are not always easy to see.

  40. To: ArndB
    With respect, my answer is the same as General McAuliffe at Bastogne: “Nuts!”

  41. Might have involved some of the SAME GLOBAL conditions that caused the “wash-outs” over and over again (warming climate, cooling climate with large glaciers) resulting in the Washington State scablands — if I have approximate dates correct. What is all this tiny, tiny cause and effect? “That coincides almost exactly….” Have our university professors become absolutely stupid?

  42. John says:
    August 6, 2010 at 6:24 am
    “”Further, the distinction between maritime and continental climates had been a standard of climatology for decades, even centuries. What is more, by the late 1990s satellite data, and analysis of numerical models into which those data had been assimilated as part of the weather-forecasting process, had shown that in mid-latitudes the poleward transport of heat by the atmosphere exceeds that by the ocean several-fold.”
    “But my reading also tells me that it is very minor factor during the interglacial we are now in (the Holocene), and that it is the jet stream, diverted south by the Rocky mountains, which as a result of the diversion is headed north by the time it nears Europe, bearing warm winds with it. Put differently, if the Gulf Stream stopped, it would have a minor effect on the European climate today. If the jet stream stopped bringing warm air, it would have a major effect today in cooling Europe.”
    “Ngar-Cheung Lau of the National Atmospheric and Oceanic Administration’s Geophysical Fluid Dynamics Laboratory (GFDL) and Princeton University had published in 1979 an observational study in which he quantitatively demonstrated the warming and cooling effects that large-scale waves in the atmosphere had in Europe and eastern North America, respectively. In the 1980s, atmosphere modelers such as Brian J. Hoskins and Paul J. Valdes at the University of Reading in England and Isaac M. Held and Sumant Nigam at GFDL had shown how such stationary waves, including those forced by mountains, warm western Europe.”
    ____________________Reply;
    I have been following up on these Ideas since 1982, and have formed a hypothesis of how the Lunar declinational tides modulate the swings in the jet streams, and have since developed a long range daily analog forecast method based on the premise of this hypothesis. Posted to the name linked web site is a forecast that is now 30 months into the 72 month set of maps I posted there back in December of 2007.
    So some things have been done to investigate the correlations, and search for causation, to disentangle the driving effects from the patterns, just not by the government paid section, but a private personal funded interested individual.
    In the next couple weeks I hope to evaluate the skill scores of the first 900 days of this forecast against the actuals for the reporting stations that I used to accumulate the data base (TD3200 Coop raw data) using all stations available, for every day from the past three cycles, to generate a composite for this cycle.
    Details on the research method and techniques can be found in the research section of the site, more will be added in the next two months.

  43. RE: crosspatch: (August 6, 2010 at 12:16 am) “Why must they always have that final paragraph about “global warming”? It seems somehow obligatory.”
    Perhaps this is the ‘obligatory’ warning that the paper is a tract of Modern Environmentalism. That’s not fair, I know.

  44. Mods – Italics are stuck on – at “Tenuc says: August 6, 2010 at 9:36 am” there’s a <i /> that should be </i>.
    Wordpress bug….
    REPLY: Yes a WP bug, we keep fixing it. -A

  45. Ed_B says: Aug 6,2010. “No need to blame humans”. They have to blame humans because otherwise there would be no money in it.

  46. Paul Vaughan says: August 6, 2010 at 3:04 am
    “Some past abrupt decreases in the AMOC have been linked to an increase of freshwater flowing off the continents into the North Atlantic.”
    Anyone have some references for this?

    Laurentide ice sheet was melting down between 18000 – 4500BC, the Hudson bay area was last to melt. (I referred to it http://www.vukcevic.talktalk.net/NATA.htm p.4)
    Volume of water contained was sufficient to raise oceans level 40-50 m. Even now some 6500 years after it disappeared, the Hudson Bay area has an uplift 2-3 m /century.
    I did quick calculation and if you assume constant TSI (ha!) (overall average 330 cu km /annum) or assuming area reduction (square law) I came up with this table:
    K years ago…………outflow cu km
    18…………1299264
    17…………921464
    16…………653520
    15…………463490
    14…………328716
    13…………233132
    12…………165342
    11…………117264
    10…………83166
    9…………58983
    8…………41832
    7…………29668
    6…………21041
    Outflow in the last millennium comes down to 1.6% of that in the first.

  47. Billy Liar says:
    August 6, 2010 at 4:24 am
    stephen richards says:
    August 6, 2010 at 2:50 am
    My thoughts too.
    Maybe it was just a névé, a patch of permanent snow/ice with no flow. Glaciers in Iceland with nearby lava have reduced the lava to black sand by repeated freeze/thaw cycles.

    My wife is a glacial geologist, er was one in graduate school, and she has explained to me that the “glaciers” on Kilimanjaro, were never thick enough to flow and become true glaciers. That is why they look to me like cuts through snow banks rather than like any glacier I have ever seen. They are essentially snow fields–Thanks, Billy, for the term Neve. Do these cut the rocks so covered off from the atmosphere as glaciers would? I dunno, but people are quick to call things “glaciers” when they are not.

  48. vukcevic etc. says: August 7, 2010 at 10:30 am
    P.S. Of course ice melt did not start at max rate, so you could take into account the Milankovic tilt change, and possibly assume no area reduction for the first couple of millennia.
    Probably as good as any proxy database (?!).

  49. Tenuc says: August 6, 2010 at 9:36 am
    I also think that a slow gulf stream would have little immediate effect on Europe, but would probably have an instant effect on the Arctic.
    I think Gulf stream left to its own devices would not vary much. The change on it is imposed by Arctic overflow through deep and narrow funnel shaped channel of highly saline fast arctic current into North Atlantic, for a more detailed view, zoom in on
    http://maps.grida.no/go/graphic/arctic-topography-and-bathymetry
    Velocity of this current was in past up to twice the current rate.
    Geomagnetic field at this point shows high degree of correlation ( Rsq=0.66) with the Loehle’s global temperature reconstruction.
    http://www.vukcevic.talktalk.net/LFC1.htm
    There is about 20 year delay between GMF and temperature.
    According Hakkinen (NASA Goddard Space Flight Center), and Rhines (University of Washington), referencing earlier data to TOPEX/Poseidon altimeter data, and translating the satellite sea-surface height data to velocities of the subpolar gyre, the subpolar gyre can take 20 years to complete its route.
    http://oceanmotion.org/html/impact/climate-variability.htm
    See also http://www.vukcevic.talktalk.net/NATA.htm

  50. crosspatch says:
    August 6, 2010 at 12:16 am
    “Why must they always have that final paragraph about “global warming”? It seems somehow obligatory”.
    That’s why they get paid.

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