Underwater Robot Reveals Hidden Base of Antarctica's 'Doomsday' Glacier 47
sciencehabit shares a report from Science Magazine: Using a robot dropped through a 700-meter hole in the ice, scientists stationed on Antarctica's Thwaites Glacier have captured the first video of the glacier's grounding line, the mysterious boundary where ice meets land and where warm ocean water could be slowly melting the glacier's base -- putting it at risk of collapse (above). Battling 2 months of stormy conditions and temperatures lower than -30C in one of Antarctica's most inaccessible locations, the researchers drilled a hole and lowered the torpedo-shaped Icefin robot into the frigid ocean waters below. Icefin then swam more than 1 kilometer along a downward-sloping basin to the grounding line, a rocky ridge below sea level that supports the glacier's huge floating ice shelf. The researchers used cameras, sonar, chemical probes, and other sensors on Icefin to study the rapidly retreating Thwaites and its supporting sediment. Scientists are still sifting through the data. But they fear warm ocean water intruding underneath the glacier could eventually cause it to retreat from the ridge, leading to its ultimate collapse.
Duplicate (Score:5, Informative)
This news story was posted a few hours ago.
https://news.slashdot.org/stor... [slashdot.org]
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This is just the runoff from the last story.
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Well, it does have fresh details over the story which ran 10 hours earlier. Not that the 65 second video was particularly impressive.
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Having looked at the BBC article - the one linked to in the earlier story - there is a lot more in there than in the article linked to this one. They even have the youtube link.
The other main difference between the BBC article and the ScienceMag article is that the first is UK-centric and the second more US-centric.
Help me out here (Score:5, Insightful)
"a rocky ridge below sea level that supports the glacier's huge floating ice shelf"
if its floating, then how can it be supported by the ground? Or if it is anchored to the ground, how can it be floating?
Re:Help me out here (Score:4, Informative)
If a ship were anchored to the ground, would it still float?
It's not a perfectly rigid, self-supported mass. Much of it is supported by buoyancy. The water underneath is denser than the ice.
Re:Help me out here (Score:5, Informative)
Icebergs sink until about 90% is under water, where they then "float". This glacier sank about 50% and then it hit the ocean floor, so it can't sink further, neither can it float. The robot swam 1 km from the hole to the "grounding line" (where the glacier is sitting on the ocean floor). The ice at the grounding line and the angle and friction of the ocean floor are the only things stopping the rest of the glacier sinking & sliding further. The warmer Southern Ocean is melting the glacier from underneath and they want to measure exactly what is happening. When the base of the glacier melts further, it will fall, slide, crack and create floating icebergs. Eventually it will all disappear and raise global sea levels - bye bye Central London, Venice, Long Island, Bangladesh, Louisiana and many Pacific Islands. And then we are in a new massive phase of human migration. (But I think migrations from India, Africa and Middle East will happen long before that due to heat and inconsistent rain making those lands unable to sustain their populations).
According to Turkish folklore, the Turks migrated, https://en.wikipedia.org/wiki/... [wikipedia.org], from Central Asia to Turkey 1000 years ago because of Central Asia becoming more uninhabitable . Human history is migrations - we migrated out of Africa, and retreating glaciers opened up Eurasia and North America. We should respect refugees today, because far enough back in history ALL our ancestors were refugees and ALL our descendants will again become refugees as climate changes - irrespective of human-induced climate change or natural climate change. Sometime in the future perhaps only Antarctica is habitable as the Earth burns, and maybe long after that only the Equator is inhabitable when an Ice Age wins again. Hopefully we have moved to the stars by then, or built habitats in space that offer great life quality - instead of killing each other in a race to the bottom because of the https://en.wikipedia.org/wiki/... [wikipedia.org].
Poe's law [Re: Help me out here] (Score:1)
Wow, that post really hits Poe's law. [ycombinator.com]
Re: Help me out here (Score:1)
Re: Help me out here (Score:1)
You. Marxist cowardly pussy.
Iceberg or ice shelf [Re:Help me out here] (Score:2)
They are wrong. It is not floating. A "glacier" that is floating is actually an iceberg.
Or an ice shelf. [nsidc.org]
The terminology "shelf" makes you think that an ice shelf is cantilevered from the land, but actually no, ice shelves float on the underlying ocean.
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No, you are wrong. An iceberg is an independent freely floating mass of ice. A glacier is not an independent mass.
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The warmer Southern Ocean is melting the glacier from underneath and they want to measure exactly what is happening. When the base of the glacier melts further, it will fall, slide, crack and create floating icebergs
The Southern Ocean forms a uniform band around the entire Antarctic Continent, relatively unobstructed by land masses as in the Northern Hemisphere.
So if the "warm", GHE-heated waters of the Southern Ocean are melting the Antarctic coast. Would not the melting occur uniformly around the continent? Yet it seems concentrated in "hot spots", such as Pine Island and the Thwaites Glacier.
And how is this warm water able to "sink" below the colder water above it? The usual pattern of ocean temperatures is a monoto
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I have a dumb dumb question about ice melting...
Ice is about 92% the density of fresh water.
Salt water is 2.5% more dense.
If 90% of an iceberg is under water, won't the melting of any ice bergs or other floating ice be a zero sum of oceans rising?
What else is contributing to the rising oceans?
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Ice that was on mountains or other higher ground, melting and trurning into ocean. that's the only thing I can guess, and I suppose that can include glaciers and antarctic ice, but not the arctic.
shelf vs sheet (Score:2)
The glacier is mostly part of the ice sheet, sitting on land, but there is a small portion at the outer edge, still a large area, that is floating. So that portion of the glacier is an ice shelf.
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Re: Help me out here (Score:1)
Disappointed (Score:3)
I was expecting aliens...
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Has /. has turned into click bait by using the word "base" in the heading? Too bad editors don't actually do their job. :-/
Hidden base? (Score:2)
Now that we know the location of the hidden underwater glacier base, we can send Agent 007 in to save the day! No more doomsday device or . . . wait, what?
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Seriously, this is almost exactly along the same lines that I first thought when I read the headline, and had initially considered the possibility that Slashdot was pulling an April 1st story in January.
Damn homonyms.
Where's the doom in this doomsday glacier? (Score:1, Informative)
Yet another global warming "doomsday" article. I will say though that this has at least more of a "news for nerds" angle than most because of some of the cool technology used to investigate the "doom" that is to come. Still, this is mostly just more of the same doom and gloom of global warming and no discussion of solutions. If someone comes up with a problem and no solution then it's just complaining. Maybe if this is a solicitation for solutions then it's productive, but I'm tired of yet more doom fro
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It's been something like a decade of hearing how solar power is cheaper than coal, wind power is cheaper than natural gas, and how the electric car has made the "infernal" combustion engine obsolete. I'm not denying anything. I've simply been convinced the global warming problem has been solved.
Shouldn't we be happy now? Should we not feel relieved? There will be no global warming catastrophe because we have found replacements for all the major causes of global warming. No more coal, no more natural ga
The problem is solvable [Re:Where's the doom i...] (Score:2)
It's been something like a decade of hearing how solar power is cheaper than coal,
True, in some markets. Graph of cost of solar panels [wikimedia.org].
Up to about 10% of current world electrical production, you can implement solar power cheaper than coal with no disruption at all. Above about 10% (maybe 30%, if you make optimistic assumptions), you start having problems with power not being available when you want it, and you need storage.
10% of world electrical production, of course, is a huge amount of power. It's certainly a good start.
wind power is cheaper than natural gas,
I don't know as much about wind, I'm afraid. Looks to me like
Not doomsday, but doesn't mean we should ignore it (Score:2)
Yet another global warming "doomsday" article.... This isn't a "doomsday glacier" because it cannot bring any catastrophic sea level rise.
I agree; the headline term "doomsday glacier" is hyperbole, and not accurate.
To be fair, always keep in mind that the people who write the headlines are not the reporters who write the articles, and headlines are almost always more scary than the actual articles are.
There will not be any global warming caused catastrophic sea level rise.
Depends on what you mean by "catastrophic". If you mean "immediate large-scale catastrophe in the next few years"-- you're right. Global warming is a long term thing-- the effect is large over a scale of centuries, not decades. The current "b
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That's an assertion with no evidence. You say "we will be lowering our CO2 emissions long before there is some kind of 'tipping point'," but there's not any particular reason we would do so unless people start worrying about the effects of global warming.
Of course there is a reason people would lower their CO2 output without worrying about the effects of global warming. This would be because solar power is cheaper than coal, wind power is cheaper than natural gas, and electric cars are more convenient, have a lower total cost of ownership, and have better performance than a dinosaur burning equivalent. Since I've been told all of this is true then we are well on our way to lowering our CO2 emissions.
The problem is solvable [Re:Not doomsday, but...] (Score:2)
I addressed this in a reply further down, where you made the same comment.
Basically, the problem is solvable, but it is not yet solved.
I do, however, agree with your technological optimism: the problem is solvable, and that is important.
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That's an assertion with no evidence. You say "we will be lowering our CO2 emissions long before there is some kind of 'tipping point'," but there's not any particular reason we would do so unless people start worrying about the effects of global warming.
We will be lowering our CO2 emissions long before there is some kind of 'tipping point' We have more than enough wealth, infrastructure, technology, and scientific understanding to adapt.
I agree that the technology is there, or could be developed, that we can reduce CO2, and we can adapt to the changes. But this won't happen if your attitude is oh, don't worry, it's all just 'fearmongering'.
The problem is that we're nearing multiple tipping points -- some of which are acceleration points. Methane clatherates and carbon currently sequestered in permafrost are two of the latter, and, of course, we don't know exactly how far we can go before one of these pops off.. Shutdown of the thermohaline circulation system in the Atlantic -- and there're signs that it's already been weakened significantly -- and destabilization of the 'arctic vortex' are already leading to really screwed up weather in the
Yeah, that's how ice works (Score:2, Insightful)
The Antarctic ice pack has been growing for decades. As it grows, the pressure on the pack pushes the edges outward, so that they extend at times beyond the land mass. The water beneath those ice shelves eventually melts that ice to the point where the shelf breaks off. The iceberg then floats into warmer water, where it dissolves, hopefully before it becomes a hazard to shipping.
The addition of ice to the ocean is one of the things that helps regulate the planet's temperature.
When did scientists start g
New Icebreakers! (Re:Yeah, that's how ice works) (Score:3)
The Antarctic ice pack has been growing for decades. As it grows, the pressure on the pack pushes the edges outward, so that they extend at times beyond the land mass. The water beneath those ice shelves eventually melts that ice to the point where the shelf breaks off. The iceberg then floats into warmer water, where it dissolves, hopefully before it becomes a hazard to shipping.
The addition of ice to the ocean is one of the things that helps regulate the planet's temperature.
Indeed. It's almost as if the planet has natural cycles of water and carbon to regulate and distribute heat into a balance between heat from the sun with that of heat lost to space.
When did scientists start getting frightened by physics? *coughgrantmoneycough*
Let's just hope they don't use this grant money to send ships into Antarctic waters only to get stuck in the ice. At least don't do that until the US Coast Guard gets another icebreaker or two to get them free. It's not just climate scientists that need to justify their spending on new equipment and manpower.
Cycles [Re:New Icebreakers!] (Score:2)
Indeed. It's almost as if the planet has natural cycles of water and carbon
Of course. The changes due to human-induced greenhouse gasses are in addition to, not instead of, natural cycles.
What is notable about the human-induced warming is how rapid it is. The warming that took us out of the last glacial maximum into the present interglacial peak was blindingly fast by geological standards.... but that "fast" warming came out to roughly 1 degree C every 700 years. We're now exceeding that by over an order of magnitude
to regulate and distribute heat into a balance between heat from the sun with that of heat lost to space.
Which is precisely the calculation that climate modelers do. H
Re:Yeah, that's how ice works (Score:4, Informative)
The Antarctic ice pack has been growing for decades.
Nope. Satellite gravity measurements show that the Antarctic ice, on the whole, is decreasing in mass, not increasing.
Nature article [nature.com].
Don't be confused by measurements of the extent of ice (the ice sheets floating on the surface)-- extent doesn't measure how thick the ice is, and in any case floating ice doesn't contribute to sea level rise.
Re:Yeah, that's how ice works (Score:5, Informative)
SeaDuck79 blathered:
The Antarctic ice pack has been growing for decades. As it grows, the pressure on the pack pushes the edges outward, so that they extend at times beyond the land mass. The water beneath those ice shelves eventually melts that ice to the point where the shelf breaks off. The iceberg then floats into warmer water, where it dissolves, hopefully before it becomes a hazard to shipping.
Uh ... no. That's not what's been happening. At all.
While it is true that the East Antarctic Ice Cap has been adding mass at its polar region, almost all of the snowfall it experiences is from moisture the prevailing westerlies pick up on their way across the rapidly-shrinking West Antarctic Ice Cap. Once the western ice cap collapses, the eastern one will rapidly begin destabilizing - because, like glaciers, ice caps are chaotic phenomena - and collapse in its turn, a century or two later.
You'll notice that each new annual report from the IPCC includes statements to the effect of "Greenland's ice cap is melting significantly faster than our models predicted." The reason for that is twofold: the scientific (their models are wrong because they're predicated on the hypothesis that glacial/ice cap melt rates are essentially linear, when all the available evidence clearly indicates that they're anything but linear), and the political (the IPCC is a UN body, after all, and the petro-states - very much including the USA - aren't going to let its reports acknowledge the true extent of the problem until it's far too late to actually do anything about it, which it's increasingly evident is already the case).
The first problem can be fixed, albeit with some loss of trust and confidence in the climate science community (driven largely by the petroleum industry's disinformation machine, to be sure, but nonetheless a real-world issue). The second one is more recondite, of course, because it exists at the intersection of politics and petrodollars. The wielders of those petrodollars are implacably determined to hold onto their income stream with both hands (and, if necessary, their teeth), and politicians the world over are fawningly-eager to help them do so. In exchange for campaign contributions, both reportable and dark.
Especially dark money, because there are no limits on that.
Oh, and as for your contention that Antarctic ice sheets somehow have been growing larger because of the added ice mass inland that you claim has been building up pressure against the ice shelf - well, none of that is true. No West Antarctic ice shelves have been adding mass. In fact, the opposite is true. They've been shrinking dramatically in this century. The same is true of ice shelves along both sides of East Antarctica; only those along the easternmost coast have actually added mass, fed by the same westerlies that have caused the ice-mass buildup in East Central Antarctica.
Every Antarctic ice shelf is fed by one or more glacier. Once those glaciers collapse, the era of ice shelves will end. The era of ice caps will shortly follow. ...
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When you say "ice pack", most people think "sea ice", but the rest of your post seems to be about ice and snow on the land. As it grows, the pressure on the pack pushes the edges outward, so that they extend at times beyond the land mass.
At times? The ends of most antarctic glaciers are floating. This has been true as long as we have been directly observing. Even the parts of antarctic glaciers that are not floating are mostly sitting on solid "land"
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When you say "ice pack", most people think "sea ice", but the rest of your post seems to be about ice and snow on the land.
At times? The ends of most antarctic glaciers are floating. This has been true as long as we
hey scientists (Score:1)
Stop flying 12 hercules fully loaded planes, along with two icebreakers.
Stop diving all over the world
Stop doing mountain expeditions all over the world.
We know global warming is a thing, we've known it for 20 years (at least in my life). If you believe it to be true (which you should), stay home, and research how we can all live local permaculture lives. Increase investment in low carbon footprint communities.
I get it, it's cooler to go be a badass on a remote glacier to drill through a mile of ice and p
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I gotta say, this is a pretty good troll. Well done. +1, Troll.
My god, it's full of ...fear (Score:2, Insightful)
Nearly every new news story has apparently been about working up people's existential fear.: of Trump, of viruses, of environmental doom.
Doesn't anyone ask why?
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We're afraid to. I'll be here all night.
Uh oh (Score:1)