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Earth Science

Melting Ice Sheets Triggered 60 Feet of Sea Level Rise 14,600 Years Ago (phys.org) 100

Posted by EditorDavid from the climate-changed dept.
"New research has found that previous ice loss events could have caused sea-level rise at rates of around 3.6 meters per century, offering vital clues as to what lies ahead should climate change continue unabated," reports Phys.org: A team of scientists, led by researchers from Durham University, used geological records of past sea levels to shed light on the ice sheets responsible for a rapid pulse of sea-level rise in Earth's recent past. Geological records tell us that, at the end of the last ice age around 14,600 years ago, sea levels rose at ten times the current rate due to Meltwater Pulse 1A (MWP-1A); a 500 year, ~18 meter sea-level rise event... The new study uses detailed geological sea-level data and state-of-the-art modelling techniques to reveal the sources... Interestingly, most of the meltwater appears to have originated from the former North American and Eurasian ice sheets, with minimal contribution from Antarctica, reconciling formerly disparate views...

The results are important for our understanding of ice-ocean-climate interactions which play a significant role in shaping terrestrial weather patterns. The findings are particularly timely with the Greenland ice sheet rapidly melting, contributing to a rise in sea levels and changes to global ocean circulation... Lead author Yucheng Lin, in the Department of Geography at Durham University notes, "The next big question is to work out what triggered the ice melt, and what impact the massive influx of meltwater had on ocean currents in the North Atlantic. This is very much on our minds today — any disruption to the Gulf Stream, for example due to melting of the Greenland Ice Sheet, will have significant consequences for the UK climate."
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Melting Ice Sheets Triggered 60 Feet of Sea Level Rise 14,600 Years Ago More

Melting Ice Sheets Triggered 60 Feet of Sea Level Rise 14,600 Years Ago

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  • People laughted, but ... (Score:4, Funny)

    by fahrbot-bot ( 874524 ) on Saturday April 10, 2021 @04:44PM (#61259508)

    The findings are particularly timely with the Greenland ice sheet rapidly melting, contributing to a rise in sea levels and changes to global ocean circulation...

    This is why the US wanted to buy Greenland, so it could build a freezer around the whole thing ... :-)

    • This is why the US wanted to buy Greenland, so it could build a freezer around the whole thing.

      And that’s why, children, the great ice age was started in 2071 when America forgot and left the fridge open.

    • The Greenland Ice sheet is a baby compared to the ice sheets in question. And so is the Antarctic one. We are talking about an order of magnitude more ice. Even if they recede at the same relative rate as the ice sheets at the end of the last Ice Age, they will not produce a meltwater event of similar intensity.

  • So 14,000 years ago was a prehistoric Waterworld staring an ancestor of Kevin Costner?

    • So 14,000 years ago was a prehistoric Waterworld staring an ancestor of Kevin Costner?

      It is very likely on the order of certain the earth, 140 centuries ago, had a Costner ancestor who danced with wolves and was very handsome once he shaved.

      Tambien, it is equally likely the earth experienced climate change that resulted in decreased water storage as ice plates, without the contribution of an advanced race of hairless monkeys... FD: I believe the science. I believe that 7 billion humans (an outbreak species) is affecting the the earth in some negative way, and, is contributing to the climate

    • Some people called him Utnapishtim, but now he's best known as Noah. Story is probably a bit exaggerated, but there are still cities underneath the Persian Gulf.

      • but there are still cities underneath the Persian Gulf.

        Citation required (but not expected).

        The coast line of the Persian Gulf, particularly at the Tigris/ Euphrates end has actually moved out into the Gulf over the time from the writing of the Utnapishtim/ Noah legend, not receded and drowned previous areas of coastal land.

        But that's only the last 5000 to 6000 years - a third of the age of the events considered here.

  • Thank god (Score:3)

    by nospam007 ( 722110 ) * on Saturday April 10, 2021 @05:24PM (#61259588)

    My NY apartment is on the 65 floor.

  • Old news (Score:4, Informative)

    by Mspangler ( 770054 ) on Saturday April 10, 2021 @06:57PM (#61259786)

    https://en.wikipedia.org/wiki/... [wikipedia.org]

    Solid geological evidence, based largely upon analysis of deep cores of coral reefs, exists only for three major periods of accelerated sea level rise, called meltwater pulses, during the last deglaciation. The first, Meltwater pulse 1A, lasted between c. 14.6–14.3 ka, a 13.5 m rise over about 290 years centered at 14.2 ka.

    The EHSLR spans Meltwater pulses 1B and 1C, between 12,000 and 7,000 years ago:

    Meltwater pulse 1B between c. 11.4–11.1 ka, a 7.5 m rise over about 160 years centered at 11.1 ka, which includes the Younger Dryas interval of reduced sea level rise at about 6.0–9.9 mm/yr;
    Meltwater pulse 1C between c. 8.2–7.6 ka, centered at 8.0 ka, a rise of 6.5 m in less than 140 years.[4][5][6]

    Such rapid rates of sea level rising during meltwater events clearly implicate major ice-loss events related to ice sheet collapse. The primary source may have been meltwater from the Antarctic ice sheet. Other studies suggest a Northern Hemisphere source for the meltwater in the Laurentide Ice Sheet.[6]

    Kevin Costner not required. A largish sailboat might be.

  • Interestingly, most of the meltwater appears to have originated from the former North American and Eurasian ice sheets, with minimal contribution from Antarctica, reconciling formerly disparate views.

    Massive glaciers that lowered sea levels during the last Ice Age melted and the former sea level was restored. Meh.

  • Timely... (Score:3)

    by clawsoon ( 748629 ) on Saturday April 10, 2021 @09:35PM (#61259994)
    ...given the precarious state of Thwaites Glacier in Antarctic [gizmodo.com], whose collapse could raise sea levels by 3 feet very quickly, and by 10 feet if its collapse leads to the collapse of its neighbour.
    • It's a pity for "It's the fault of our greenhouse gas emissions" doomcryers that the warm water under the Thwaites glacier is geothermal in nature [sciencedaily.com] (with further references [google.com]). Even taking all the CO2 out of the atmosphere isn't going to affect a magma plume. But, then, that doesn't boost the anthropogenic climate change agenda, so it gets quietly swept under the rug while the articles imply that it's due to CO2 emissions.

  • In those days, Republicans did not exist.

  • Gibralter waterfall (Score:4, Insightful)

    by dltaylor ( 7510 ) on Saturday April 10, 2021 @10:30PM (#61260072)

    The Mediterranean Sea has dried up repeatedly during ice ages. I would very much like to see the waterfall as the Atlantic Ocean refills it. A smaller version also existed at the Bosporus Straight, perhaps in only a few thousand years ago.

    Take a look at the Gibraltar Straight on the NOAA map: https://maps.ngdc.noaa.gov/viewers/bathymetry/ [noaa.gov]

    There's a steeply-banked, narrow channel that appears to have been carved by rushing water.

    • Sorry, but the various Messinian salinity crises happened 5-6 million years ago - 3-4 million years before the current Ice age got well started.

      Take a look at the Gibraltar Straight [...] There's a steeply-banked, narrow channel that appears to have been carved by rushing water.

      More to the point, there are also steeply incised canyons below present sea level for most of the rivers that enter the Mediterranean basin, showing that the water level was far below the current level across most of the area of the

  • Remember that the CO2 levels are now at an 800,000 year high, at a minimum.

    https://www.co2.earth/co2-ice-... [www.co2.earth]
    https://cdiac.ess-dive.lbl.gov... [lbl.gov]

    This sea level rise happened when CO2 levels peaked at about 350ppm (actually less).

    So this WILL happen, it's baked into the cake, and there will be quite a few humans around to see it happen.

    Your dystopian future, coming soon to a planet near you.

  • It was all those darn campfires outside and in caves the melted those ice sheets. But smoke signals were a revolutionary form of communication. How else would Oogtar know of the cat mere I drew on my cave's wall?

    • In other words: "If humans didn't case climate change 14,600 years ago, they can't possibly be causing climate change now!"

      Genius, pure genius.

      • Re: (Score:2, Troll)

        by srmalloy ( 263556 )

        In other words: "If humans didn't case climate change 14,600 years ago, they can't possibly be causing climate change now!"

        More "If humans didn't cause climate change 14,600 years ago, what did, and what could we be missing behind all of the people rushing to line up behind the IPCC's blind assumption that CO2, and only CO2, is the cause of the recent warming? If it's happening again, the single-minded drive to eliminate anthropogenic CO2 emissions could be throwing money down a rathole when it could be better spent on improving life in general."

        • So, just to establish your argument, you are completely discounting the high level of CO2 in our atmosphere right now, the highest it's been for at least 800,000 years, in order to wonder what might have happened 14,600 years ago that may have caused a similar effect? And you think we should ignore everything we know about the green house effect and the fact that our planet is warming right now and instead spend a lot of money and time looking to see if something outside our control is magically causing th

  • Yup, things could really get bad 14,600 years from now. I'm moving to the top of Mt.Everest right away.

  • So much information shows the earth goes through warming and cooling periods. This new information, plus the Maunder Minimum which lasted 400 years, during which our Revolutionary war occurred, the Missoula floods which happened often in the past and created much of the topography in the Pacific Northwest and Greenland, which was called that because it was warm enough to grow food crops. Since they cannot predict it's behavior, climate models ignore the fickle nature of the sun which goes through periods
    • It would be nice if people presented solutions that kept at least one eye on cost/benefit ratios instead of just appearing to be doing something. I'm all for keeping things clean, but it would be insane to focus so much on it that we forget that we still have to feed ourselves, or screw ourselves out of the resources and energy to fix the problem in a blind rush to mitigate it.

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