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Earth

15 Months Ago, a Melting Iceberg Released 152 Billion Tonnes of Water (space.com) 62

Space.com reports: A rogue iceberg that drifted dangerously close to an Antarctic penguin population in 2020 and 2021 released billions of tons of fresh water into the ocean during its breakup.

A new study, based on satellite data, tracks the aftermath of the once-mighty iceberg A-68a, which held the title of world's largest iceberg for more than three years before shattering into a dozen pieces.... [T]he new research shows that the iceberg flooded the region with fresh water, potentially affecting the local ecosystem and providing yet another example of the effects of global warming on the oceans.

The research consulted data gathered by missions including Sentinel-1 (operated by European Space Agency, or ESA), Sentinel-3 (ESA), CryoSat-2 (ESA) and ICESat-2 (NASA), as well as the Moderate Resolution Imaging Spectroradiometer, or MODIS, instrument that flies aboard two NASA satellites, Aqua and Terra. The satellite data shows that during the iceberg's three-month melting period in late 2020 and early 2021, the former A-68a flushed into the ocean about 162 billion tons (152 billion metric tonnes) of fresh water — equivalent to 61 million Olympic-sized swimming pools, according to a press release from United Kingdom study participant University of Leeds.

"Our ability to study every move of the iceberg in such detail is thanks to advances in satellite techniques and the use of a variety of measurements," said Tommaso Parrinello, CryoSat Mission Manager at the European Space Agency, in the press release.

The BBC reports that the "monster" iceberg "was dumping more than 1.5 billion tonnes of fresh water into the ocean every single day at the height of its melting."
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15 Months Ago, a Melting Iceberg Released 152 Billion Tonnes of Water

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  • by godrik ( 1287354 ) on Sunday January 23, 2022 @05:28PM (#62200355)

    In case you wonder, that's about 0.3mm of water rise or so. (convert tonnes to cubid meter, divide by earth surface)

    • I got 1.4mm over the area of the oceans, or just under 1mm for the entire surface but math is hard.

    • by ishmaelflood ( 643277 ) on Sunday January 23, 2022 @05:54PM (#62200399)

      Unfortunately your eagerness to do a calculation has prevented you from understanding the physics of flotation. A 15 billion ton iceberg floatss because it is displacing 15 billion tons of water. When it melts the water takes up exactly that much volume, hence no net change in sea level. (there may be some tiny second order effects)

      • Mod parent up. Icebergs displace the same weight of water. Ice bergs have a lower density so it sticks out. When an iceberg melts, the density becomes equal so the water from the iceberg fills in the iceberg sized hole. No rise in sea level noticed.
        • by Anonymous Coward

          Mod parent up. Icebergs displace the same weight of water. Ice bergs have a lower density so it sticks out. When an iceberg melts, the density becomes equal so the water from the iceberg fills in the iceberg sized hole. No rise in sea level noticed.

          All true, but icebergs come from floating ice shelves. If those ice sheets are calving at the same rate they are getting new ice, the system is static. There are a number of ice shelves that aren't static. A-68 came from such an ice shelve. Larsen C is nearly completely gone. Yes, that doesn't raise sea level, but grounded ice can now flow much more easily into the ocean. That will actually raise sea level.

          • Honestly I think rising sea levels are the most overblown concern ever. When people do get displaced, it will be so gradual that the only people who will notice are going to be super wealthy people with beach front property.

            The most liberal estimates say about 8.2 foot rise between 2000 and 2100, basically a little less than an inch per year. None of us will be alive long enough to see any cities submerge. Except maybe New Orleans. New Orleans was always on borrowed time from the moment it was founded. With

            • by drinkypoo ( 153816 ) <drink@hyperlogos.org> on Monday January 24, 2022 @08:04AM (#62202065) Homepage Journal

              Honestly I think rising sea levels are the most overblown concern ever. When people do get displaced, it will be so gradual that the only people who will notice are going to be super wealthy people with beach front property.

              In many beach towns, it's the poorest people who live at the lowest altitudes, and who will be washed away first. The wealthy tend to live on hills overlooking the town, so they can get the view of the ocean without having to smell the serfs. For example in Santa Cruz the lowest-cost homes are in the beach flats, which occupy the flood plain behind the Santa Cruz Beach Boardwalk. I've known lots of people who have lived in them, many of whom were just scraping by.

              The same sort of thing is true up here where I live now in Humboldt County, whether you're talking about Fortuna or Eureka or what have you. The lowest property values are on the flood plain.

              Further, what many people ignore about sea level rise is that a small increase in sea level can equate to a large difference in inundation distance when there is a large storm, tsunami, etc, because of beach slope [researchgate.net]. Where the slope is steep the difference is not magnified much; where it is shallow, it is magnified a great deal.

              • by jaunty ( 56283 )

                Honestly I think rising sea levels are the most overblown concern ever. When people do get displaced, it will be so gradual that the only people who will notice are going to be super wealthy people with beach front property.

                In many beach towns, it's the poorest people who live at the lowest altitudes, and who will be washed away first. The wealthy tend to live on hills overlooking the town, so they can get the view of the ocean without having to smell the serfs. For example in Santa Cruz the lowest-cost homes are in the beach flats, which occupy the flood plain behind the Santa Cruz Beach Boardwalk. I've known lots of people who have lived in them, many of whom were just scraping by.

                The same sort of thing is true up here where I live now in Humboldt County, whether you're talking about Fortuna or Eureka or what have you. The lowest property values are on the flood plain.

                Further, what many people ignore about sea level rise is that a small increase in sea level can equate to a large difference in inundation distance when there is a large storm, tsunami, etc, because of beach slope [researchgate.net]. Where the slope is steep the difference is not magnified much; where it is shallow, it is magnified a great deal.

                I don't know where you live, but the poorer people most assuredly do not live near the beach. If anything, the poorer people live very far from the beach, in areas which are prone to flooding or slides. The rich folk are the ones with second homes on the beach, or something resembling a mansion and surrounded by hectares of land if it's their primary home (uber rich, you're not part of this conversation...).

            • by mspohr ( 589790 )

              Sea level will rise slowly so people can adapt.
              The problem is all of the crazy weather... hurricanes, typhoons, etc. The extra water combined with extreme weather leads to more severe flooding, etc. Seawalls are easily over topped.

            • by dryeo ( 100693 )

              Except sea level is a lot more complex then an inch a year rise everywhere.
              Consider tides, maximum variation of about 37 inches (about 31 inches average) in an ideal ocean covered world with similar numbers in the open ocean translates into 50 ft tides at the extreme in places like the Bay of Fundy. Seems an extra inch could translate into over an extra foot of high tide there.
              Where I am, similar has been happening, the high tide is getting high enough that it demolished the 100 year old seawall when combin

    • Only glacial melting contributes to ocean rise, not icebergs since they float. You can do this test yourself by throwing icecubes into a glass and then filling the glass to the brim with water and marveling at how the melting ice doesn't cause the glass to overflow.

      • by mspohr ( 589790 )

        Correct.
        However, the problem is that icebergs break off from glaciers on land. As they break off, the glacier moves down to the ocean. This leads to ocean level rise.

    • Nope. Floating ice that melts does not change the level of water. Always displaces its weight. See Archimedes.

  • The iceberg was already floating, so it wasn't really dumping anything, the water water was changing phase and shrinking a little.
    • The iceberg was already floating, so it wasn't really dumping anything.

      It added a layer of fresh water to the surface. The change in salinity affects the ecosystem.

      • When the water froze to make the ice shelf, the surrounding water became more salty - so the creatures living there are used to salinity changes.
        • by Eris13 ( 647245 )
          That would work if it was frozen sea water. It's not. It took Millions Of Years to get to that size and the ecosystem had time to get used to any salinity changes. Nothing can get used to 1-2 years of rapid iceberg melt in the local area and killing off the krill. I can't help you if you have never added ice to a drink and cannot visualise the effect it has on the flavour.
        • When the water froze to make the ice shelf, the surrounding water became more salty

          Nope. When the water freezes, the ice is freshwater, and the remaining seawater has a high density because it is both salty and cold. So it sinks. It does not stay on the surface as meltwater does.

          Antarctic bottom water [wikipedia.org] from freezing ice fills all the world's oceans below 4000 meters.

  • 152 km^3 (Score:4, Informative)

    by ShanghaiBill ( 739463 ) on Sunday January 23, 2022 @05:30PM (#62200363)

    equivalent to 61 million Olympic-sized swimming pools

    A more sensible measure is that a billion tonnes of water is a cubic kilometer.

    So 152B tonnes is 152 km^3.

    • There are approximately 1.3 billion cubic kilometers of ocean water. So the amount of fresh water in this ice berg is insignificant when you consider the scale. Just the Amazon river discharges about 6600 cubic kilometers of fresh water into the ocean per year.

      I'm sure the hand wavers will mod me down anyway.

      Best,

  • Dubai city is known for clearly over the top mega projects of dubious sustainability and even more dubious concern for ecology. Dredgers pumping sand from the bottom of the sea to form sand bars to create brand new beach front property! [google.com] Done!. Concern for local marine life? None!. The alliteration of Dubai and Dubious projects seems to divinely inspired.

    Well, I digress. Where was I? Oh, yeah. Ice bergs melt dump billions of tons of fresh water into the ocean devastating fragile ecology of Antarctica.

    • If I recall that palm sand monstrosity has all kinds of issues with stale and stagnant water in it due to the design of the thing.

      It'll wash away in 500 years.

    • Dubai city is known for clearly over the top mega projects of dubious sustainability and even more dubious concern for ecology.

      What would you want to see UAE do about their impact on the local ecology? Perhaps build some power plants using technology with a long history of low CO2 emissions, minimal air and water pollution, safety, and high EROEI? I believe UAE is doing just that. UAE has two operating nuclear power plants, with two more under construction: https://www.world-nuclear.org/... [world-nuclear.org]

      All the corrupt politicians, criminals, money launderers, terrorist funders are all investing in Dubai real estate keeping the bubble inflated.

      These same people appear to be investing in solar and nuclear power in UAE because that land is worthless if they can't keep the lights on a

      • by ghoul ( 157158 )
        Instead of preventing fish from dying Dubai will probably hire a bunch of Pakistanis and Filipinos to collect the dead fish and take it to a landfill. That they built a skyscraper with a septic tank and a fleet of tankers to move the shit instead of a sewage system shows that their solution to every problem is throw more cheap labor at it.
    • That doesn't seem like that bad of an idea .. except .. a desalination plant with the latest tech might be a better solution.

    • by twosat ( 1414337 )

      Just a few days ago I saw a news video about a spectacular advertisement featuring the Burj Khalifa skycraper and how it was filmed . https://www.youtube.com/watch?... [youtube.com]
      https://www.youtube.com/watch?... [youtube.com]

  • providing yet another example of the effects of global warming on the oceans.

    Wow. Let's stop global warming so we don't have any more of these scary icebergs. We can't have icebergs floating near penguin populations.

    • Wow. Let's stop global warming so we don't have any more of these scary icebergs. We can't have icebergs floating near penguin populations.

      Didn't you hear that we solved the problem of global warming already? You see solar power is cheaper than coal, wind power is cheaper than natural gas, and electric vehicles have a lower TCO than any hydrocarbon burner. Nobody will ever again invest in fossil fuels because it costs too much to do so. All that is left in fossil fuels is sunk costs in infrastructure getting paid off and being replaced with renewable energy alternatives. At least that's what so many people want us to believe. I mean they

      • Now that I see my post moderated up it's going to undergo a tug of war on further moderation. There's going to be the people that support nuclear power as a means to mitigate global warming moderating it up. There's going to be the opponents to nuclear power moderating it down. That will then result in my post going up to +5, where it can go no higher, or get moderated to zero, to where people overlook it because of the moderation threshold they set.

        That moderation doesn't change the fact we solved globa

  • This is fantastic news. Reducing the salinity of the ocean by releasing fresh water into it will increase its ability to act as a carbon sink, capturing carbon dioxide from the atmosphere and creating a thriving environment for oceanic plant life, algae, and other crucial food sources for marine animals.

  • Can't we put the iceberg in jail for this?

  • I need context. How many billions of tons in the oceans?
    • I need context. How many billions of tons in the oceans?

      A full Carl Sagan's worth. Billions of billions.

    • 1 billion (as in 1E9) tons of water per cubic kilometer, and the ocean is 1.4 trillion (1.4E12) cubic kilometers.

      Therefore the ocean weighs 1.4E21 tons, that's a one and a four with 20 zeroes after it. That iceberg's water was a gnat's fart in a hurricane.

    • Equivalent to 8.4 days of flow from the Amazon - or something like that. Not like all the other rivers are doing something too.

  • by argStyopa ( 232550 ) on Sunday January 23, 2022 @10:53PM (#62201027) Journal

    Any article reporting "billions" of anything without context - eg 'this iceberg released 150 bn tons of fresh water - is trying very hard to convince you of something.

    For example, this article states that Antarctica melts https://www.theworldcounts.com... [theworldcounts.com] 127 bn tons a year.

    Was this single iceberg really 20% more than an ENTIRE YEAR'S ice melt?

  • How about comparing the 1.5 billion tonnes of water per day to how much water the major rivers do the same? Wouldn't that be a more illustrative & realistic comparison? I mean, X million swimming pools? What does that illustrate?
  • Asking for a friend.

  • Imperial ton = 2240 pounds. Metric tonne = 2204.6 pounds. So 162 billion tons = 164.6 billion tonnes, not 152.

You can tell how far we have to go, when FORTRAN is the language of supercomputers. -- Steven Feiner

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