Arthur T Knackerbracket has found the following story:
Storm-driven ocean swells have triggered the catastrophic disintegration of Antarctic ice shelves in recent decades, according to new research published in Nature today.
Lead author Dr Rob Massom, of the Australian Antarctic Division and the Antarctic Climate and Ecosystems Cooperative Research Centre, said that reduced sea ice coverage since the late 1980s led to increased exposure of ice shelves on the Antarctic Peninsula to ocean swells, causing them to flex and break. "Sea ice acts as a protective buffer to ice shelves, by dampening destructive ocean swells before they reach the ice shelf edge," Dr Massom said. "But where there is loss of sea ice, storm-generated ocean swells can easily reach the exposed ice shelf, causing the first few kilometres of its outer margin to flex."
"Over time, this flexing enlarges pre-existing fractures until long thin 'sliver' icebergs break away or 'calve' from the shelf front. This is like the 'straw that broke the camel's back', triggering the runaway collapse of large areas of ice shelves weakened by pre-existing fracturing and decades of surface flooding."
Study co-author Dr Luke Bennetts, from the University of Adelaide's School of Mathematical Sciences, said the finding highlights the need for sea ice and ocean waves to be included in ice sheet modelling. This will allow scientists to more accurately forecast the fate of the remaining ice shelves and better predict the contribution of Antarctica's ice sheet to sea level rise, as climate changes. "The contribution of the Antarctic Ice Sheet is currently the greatest source of uncertainty in projections of global mean sea level rise," Dr Bennetts said.
-- submitted from IRC
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @02:14PM (21 children)
Do they have a picture of one of these waves?
(Score: 3, Informative) by janrinok on Saturday June 16 2018, @02:25PM (20 children)
It is not a wave [wikipedia.org] as you probably imagine it, but a swell [wikipedia.org]. Although both are sometimes referred to as 'waves' the surface or wind wave is created by relatively local meteorological conditions, whereas swell is a mechanical wave usually as a result of distant weather conditions.
The wiki links provide a better explanation.
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @03:16PM (19 children)
That page does have pictures of a swell: https://en.wikipedia.org/wiki/File:Early_90%27s_Bangs.jpg. [wikipedia.org]
I'd like to see a picture of one of the antarctic swells that "trigger catastrophic disintegration" they are going on about.
(Score: 2) by janrinok on Saturday June 16 2018, @04:29PM (13 children)
(Score: 1, Interesting) by Anonymous Coward on Saturday June 16 2018, @04:58PM (12 children)
Taking a picture/video of what you are studying conveys the unarticulatable details about what you are doing. Like if you do some experiment with rats there should be a picture of the rats in the maze so people get a sense of the size of the maze, material its made out of, etc. It also shows you actually did something so probably arent just making up the charts.
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @05:52PM
As the other person akready said there is nothing to video. You wont see much movement, this is a massively distribured effect over tome, youd need a really good time lapse if anything.
My bet is this is just another #fakescience conspirscy attempt to say this is more climste bullshit.
(Score: 2) by janrinok on Saturday June 16 2018, @05:53PM (10 children)
Swell is not measured by taking pictures. The data is collected from tethered buoys which are fitted with an accelerometer. As the buoys rise and fall with the swell, the movement is recorded and data so gathered analysed later. By having fields of tethered buoys it is also possible to identify the direction of the swell (although some buoys do this my measuring the angle that the tether is being pulled by the buoy), and the speed.
I'm trying to find an internet reference to a site that explains more about it but it is Saturday evening here and my wife would prefer that I don't spend all my time on the computer, having spent several hours today monitoring the site as I often do each day.
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @06:01PM (9 children)
And the timing of the rat in the maze isn't measured via pictures either. Here is a picture of a swell:
https://swelllinesmagdotcom.files.wordpress.com/2014/07/inside-aliso-marble.jpg [wordpress.com]
Heres another one:
https://upload.wikimedia.org/wikipedia/commons/e/e0/Easterly_swell%2C_Lyttelton_Harbour%2C_29_July_2008.jpg [wikimedia.org]
There is quite a bit of variation there. I just wanted to see a picture of these swells to understand what they are talking about.
(Score: 2) by janrinok on Saturday June 16 2018, @06:29PM (8 children)
In which case you need to read the research paper that is mentioned in TFS and look at the data there. The data is published so with a bit of judicious searching you should be able to find it.
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @06:41PM (2 children)
I looked at the paper. The closest they come is a couple plots of "significant wave height" and "peak wave period" in the supplements. Not a single picture of a swell.
(Score: 3, Informative) by dry on Sunday June 17 2018, @01:57AM
In deep water, a swell is pretty boring and I'd think, hard to do justice in a picture. Think of a long low amplitude wave.
(Score: 2) by janrinok on Sunday June 17 2018, @07:52AM
As I said, they don't need to photograph the swell as the data collection is automated. However, if you just want to see pictures of swell then Google (Images) has plenty, and the original research paper will usually either contain the actual data that was analysed, or tell you where the data can be found. For the paper to be credible the data has to be available for others to analyse independently.
(Score: 2) by Hawkwind on Sunday June 17 2018, @03:28AM (4 children)
Placing this here as deniers are jumping all threads, but you seem to be familiar with the topic. What is the new part here? I recently saw a talk by a prof from U of W (sorry, only cell phone right now), and he mentioned how increased temperatures below the surface are accelerating calving, and that it was worse in Antartica. This paper seems a modest step regarding the mechanics of an issue already recognized.
(Score: 3, Interesting) by janrinok on Sunday June 17 2018, @08:20AM (2 children)
I'm afraid my knowledge is now somewhat out of date. My take on the paper is that in the past the swell effect was dampened by the sea ice. The sea ice is now significantly less than it was a decade or two back and so the dampening effect is not occurring. As a result, the swell is also reaching further under the glacial ice with sufficient energy to cause the ice to crack and calve more easily and extensively than it used to.
There is nothing new in the actual mechanics of the event, as you correctly point out, but the extent to which it is occurring is increasing over the period of time that measurements have been taking place. Glacial ice can sometimes take millennia to form and the detached ice flows follow the sea currents to warmer climes where they melt. Also, scientists are noting a small but significant increase in the strength of storms and other meteorological conditions that create the swell often thousands of kilometres from where the damage is taking place. Together there is a change which is why the conditions that are being measured today are noteworthy.
I am not claiming that the cause of this combination of conditions is down to any specific factor. It might be something that has occurred many times in the past before we started measuring and recording such phenomena. However, that does not mean it is not occurring now. Denial of the event seems to be pointless as the evidence is there for all to see. As the rise in ocean levels is measurable and there has been no catastrophic flooding recorded over the last few hundred years, it suggests to me that the event is not one that occurs frequently and what we are witnessing today is significant - if only from a position of rarity or uniqueness. Perhaps it will correct itself over time, perhaps it won't. My knowledge of the matter is at a very superficial level and I will leave it to those with significantly more expertise in the subject to identify the causes and possible outcomes of the events we are now seeing.
(Score: 2) by janrinok on Sunday June 17 2018, @08:22AM
s/ice flows/ice floes/
I should have spotted that one!
(Score: 2) by Hawkwind on Monday June 18 2018, @04:31AM
Thanks for the answes! I do have to say number of buoys now measuring the water is pretty impressive, and this article is a good update from those measurements.
Good stuff
(Score: 3, Interesting) by janrinok on Sunday June 17 2018, @08:46AM
An alternative answer to your question - which perhaps puts it more clearly into perspective. It is not the actual mechanics that have changed but the fact that 11,500 years of glacial build has been lost in a relatively short period of time with additional knock-on effects as a result.
(Score: 2) by maxwell demon on Saturday June 16 2018, @05:30PM (4 children)
It's not "one catastrophic swell", but the constant action of small swells that weaken the ice until finally one is the straw that breaks the ice shelf's back. That one not being somehow exceptional.
It's like asking what the specific oxygen atom looked like whose reaction finally caused the breakdown of the rusty car. It looked like all the others.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @05:47PM (3 children)
You're saying these are fungible swells? Even in that case, we already know what an oxygen atom "looks like", but not an antarctic swell... How big are they, etc.
It sounds like they are basically proposing that the ice is being subjected to chinese water torture by global warming. Water droplets can be as large as 1 cm across [wiley.com], or as small as 2-6 femtometers [dailymail.co.uk]. Wouldn't the effectiveness depend on the size of the droplets?
(Score: 2) by maxwell demon on Saturday June 16 2018, @05:55PM (2 children)
What droplets? We are talking about swell here, not about spray.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @06:19PM (1 child)
The droplet size was in reference to the chinese water torture analogy. Droplet size -> swell size/etc. I don't know what other relevant properties there may be regarding swells, but that's why I want a picture of what we are talking about here.
(Score: 2) by janrinok on Sunday June 17 2018, @08:33AM
The wiki link that I provided earlier explains that swell sizes of around 50 feet can be generated by wind speeds as low as 92 km/h (57 mph). Such wind speeds are by no means uncommon. It follows that for storms of a long duration at a distance of several thousand miles can generate even larger swells which are capable of causing significant damage. The energy level of the swell can also be amplified by the rising of the sea bed as it approaches land. This is not something that might appear violent to the casual observer but the huge amounts of energy which must be dissipated when the swell meets land - or glacial ice - can have disastrous effects.
(Score: 2, Redundant) by requerdanos on Saturday June 16 2018, @02:55PM (21 children)
I wonder if, at any location, the Antarctic's ice shelf is growing via the natural process that created it, that we might be able to compare that to the rate of loss and find a net rate of loss, to evaluate how significant it is.
Something I found interesting from TFA is this observation:
So, tempering the article's preferred vocabulary of catastrophe, devastation, etc. is the message that ice flows that are slow, glacial, barely moving are being multiplied by a factor of 3 to 8 for a limited time after the "catastrophic events" (and a tiny factor multiplied by 3, or 8, is still a tiny factor).
I'd prefer the ice be preserved.
Failing that, I'd prefer reports on university studies about it that don't use inflammatory language.
Failing that*, it's evident that everyone's got an agenda and it's hard to know what to believe without being an expert yourself. The University of Adelaide is a lot closer to Antarctica than I am, so I will just hope that they are taking it seriously.
--------
* = the world we live in. You just don't see people talking about important matters like our changing climate without inflationary language indicative of their predispositions. Catastrophe, we are all going to die this, or it's all fake, there is nothing to it that. Neither position is responsible nor evidence-based. Whichever position you "believe", know that when you see language and keywords in information that show a predisposition toward selling you on one view or the other, you aren't looking at data nor evidence, but propaganda. Shame.
(Score: 3, Informative) by Thexalon on Saturday June 16 2018, @03:56PM (4 children)
Or a much shorter version: This report disagrees with your denial that climate change is happening or having a bad effect on anything. Therefor, logically, it must be false or exaggerated.
Wow, I'm sure nobody who studies ice in Antarctica would ever have thought to measure that. Why, your sheer brilliance means that all those scientist types must be missing something important. Except, of course, they did measure Antarctic ice overall [theatlantic.com].
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 1, Flamebait) by requerdanos on Saturday June 16 2018, @04:45PM (3 children)
Let's think about this. Now, you didn't, but let's do it now.
I mentioned the "important matters like our changing climate" (temperatures are changing upward which affects climate) and, of the ice shelf, I assume a "net rate of loss" (not gain)(because ice is being lost, see previous temperature change).
Then, I pointed out that "when you see language and keywords in information that show a predisposition toward selling you on one view or the other, you aren't looking at data nor evidence, but propaganda."
Your reality-ignoring emotional knee-jerk reaction to that second part, attacking your sacred cow of "we must use emotionally charged, inflationary catastrophe language when discussing climate", resulted in your calling me a "climate change denier", despite the facts that I called our changing climate an important matter, and despite the fact that I pointed out that the "it's all fake, there is nothing to it" position is irresponsible and not based on evidence.
Global temperatures are warming, causing ice loss in Antarctica which is contributing to sea loss affecting the entire world.
For crying out loud, isn't that bad enough? Must you also go on a fact-free rant against discussing it rationally, instead of using emotionally charged propaganda? And calling anyone who takes climate change seriously, but thinks you emotional charged propaganda people are clownish buffoons, a "denier"?
To the reader: This is the "Shame" I alluded to in my previous post.
Climate change is bad enough that we should discuss it seriously.
Any self-righteous ass who demands that we not discuss it seriously, but rather worship them and their inflationary propaganda, is an impediment to studying the situation and reacting appropriately. Not its champion. Regardless of the lies they spew.
(Score: 2) by Thexalon on Saturday June 16 2018, @06:14PM (2 children)
Based on your posting history, your consistent position is: "Climate change is happening, but it's not a big deal, so don't worry about it or do anything about it."
The evidence is that that position is not accurate. As for Al Gore, I'll just say that I wish he hadn't gotten involved, since he's a perfect straw man for those who would like to pretend that the problem of climate change isn't a serious problem.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 1, Flamebait) by requerdanos on Saturday June 16 2018, @10:05PM
That position is in fact not accurate. It's not a big deal because people insist on connecting it with the imminent end of the world with cataclysmic disaster language not based on reality. It is, rather, a big deal because what we are doing to our own climate through pollution and environmental mismanagement have consequences that are bad enough on their own without also using inflationary language as a god to be worshiped.
And that's been my consistent position: The consequences of our harm to our climate are bad enough on their own without also using inflationary language as a god to be worshiped. The reality is bad enough. The Earth does not need people to lie on its behalf when the truth will do a better job.
In addition to being a blowhard ass, I must admit that he's also done work in the areas of carbon sequestration via carbon credits and trying to reduce and limit human-caused greenhouse gas emissions. His influence hasn't been all bad. If he wasn't such a slimy catastrophe-promoting liar, I would think his heart's in the right place. (But he is, and it probably isn't.)
And in focusing on deliberately exaggerated, catastrophe-centered inflationary language, Gore is certainly not alone--TFA here does the same, to a lesser extent, and it's a frequent emotional argument that the pro-catastrophe nuts (who are just as wrong as the denier-nuts) stick to as a tenet of dogma. They're wrong.
You are declaring that I am a "climate change denier" based on my being concerned over the data, the reality, the problems we face, and not because of erroneous and frankly counterproductive emotional declarations of the imminent destruction of the planet.
Frankly, that's the same thing your buddy Gore [dailycaller.com] does*, as recently as several months ago, and you're both equally wrong to the extent that you do.
I am not explaining this because I believe that I can convince you that reality is better than really attractive lies; rather, because I want you to know what I think of your line of argument, and by proxy, what a group of people thinks about the group of people who think as you do, in order to hopefully contain it a bit. Because as long as we are arguing over "which lie" we should follow, as the most vocal voices on climate change insist we do, then we are not doing anything about it, and that's bad.
---------------------
* "Reporter Confronts Al Gore On Sea Level Rise Claims, Gets Called A ‘Denier’" [dailycaller.com], The Daily Caller, August 17, 2017.
(Score: 2, Touché) by khallow on Sunday June 17 2018, @01:22AM
Don't bogart that stash of evidence! Let us know why that position is not accurate.
(Score: 1, Redundant) by Runaway1956 on Saturday June 16 2018, @04:03PM (12 children)
Yep. When I read the title, just about my first thought was, "So, ocean swells had no effect on the ice until we looked for effects? There were no ocean swells hammering the ice ten years ago, but now there are?"
Which just leads me back to one of my own main objections to all the global warming hype. How do we KNOW what was happening here, there, or elsewhere, thousands of years ago, before we ever started measuring things? We don't know, at all. At best, we make "educated" guesses - and a lot of those guesses aren't so very educated. When there is an agenda to push, the agenda gets pushed.
Full circle - a decade ago ocean swells had zero effect on sea ice, but because of man-made global warming, those sea swells are destroying the entire Antarctic ice cap. Damn - now I need to go back to that article about depression . . .
(Score: 3, Insightful) by maxwell demon on Saturday June 16 2018, @05:43PM (7 children)
If you hadn't stopped at the title, but read the summary, you would have gotten the answer to your question:
The ocean swells always had an effect, but in the past there were less strong swells which meant less of an effect. And there were less strong swells because sea ice dampened the swells.
How do we KNOW what was happening here, there, or elsewhere, thousands of years ago, before we ever started measuring things?
From the summary, emphasis by me:
The Tao of math: The numbers you can count are not the real numbers.
(Score: 1) by khallow on Sunday June 17 2018, @01:25AM (4 children)
Unless, of course, that wasn't true. Always the problem with making assertions about knowledge gaps.
(Score: 2) by dry on Sunday June 17 2018, @02:11AM (3 children)
I watched a documentary on an Arctic village that was getting washed away by the swells that had shown up due to no ice cover in the summer. It was pretty dramatic, houses falling into the ocean, the villagers having to move inland and the shoreline made out of easily eroded material. This village had existed for at least 50 years without problems until the last few years when the sea ice retreated and the island itself still existing points to a long time with calm ice covered seas.
(Score: 1) by khallow on Sunday June 17 2018, @03:35AM (2 children)
The problem is that the world is always changing. There's always something dramatic happening.
50 years isn't a very long time nor would the village be built far away from the sea.
(Score: 2) by dry on Sunday June 17 2018, @04:04AM (1 child)
That's not the point. The point being that change can bring destructive swells.
Once again you miss the point, at least 50 years more likely closer to 75 since they were forced to settle into housing and the people have been living there for thousands (10+?) of years, and the fact that the island was very erodible. I've lived on the ocean, erosion doesn't happen very fast as the easily eroded shoreline is long eroded away.
(Score: 1) by khallow on Sunday June 17 2018, @12:14PM
Not from your story, it isn't. The media wouldn't have been interested in that island being slowly eaten up (or perhaps eaten up in bouts over thousands of years), until houses started sliding into the sea. I grant that global warming presents a plausible scenario with a combination of loss of protective ice and thawed permafrost could result in highly accelerated local erosion. But that might just be a phenomenon that's been repeated for thousands of years. It's only now that we've had a chance to see it in action.
The houses weren't thousands of years old. In the past, they would have just moved inland a bit and nobody would have reported on the situation both due to the lack of media and the lack of drama.
Unless there's a lot of shoreline to erode, such as with the cliffs of Dover.
(Score: 2) by Runaway1956 on Sunday June 17 2018, @01:30AM (1 child)
See Khallow's response. The assertion that ocean swells weren't so strong fifty, or a hundred, or a thousand years ago is preposterous.
(Score: 0) by Anonymous Coward on Sunday June 17 2018, @05:18PM
Which has no besring on the topuc really since the problem is lack of sea ice absorbing the energy.
(Score: 2) by ilPapa on Saturday June 16 2018, @06:11PM
My favorite thing is when climate change deniers are pissed at education.
My friend, it is better to light a candle than curse the darkness.
Long before there was an "agenda to push", Frank Capra made this nice short film about weather and climate change. I recommend it. Maybe after watching it, you guesses will be more educated. It has cartoons in it so you won't get too bored.
https://youtu.be/x1ph_7C1Jq4 [youtu.be]
You are still welcome on my lawn.
(Score: 3, Insightful) by Thexalon on Saturday June 16 2018, @07:09PM (2 children)
Holy argument from ignorance, batman!
You don't understand the methods used to collect the data (nor have you attempted to collect the data yourself, I'm guessing). Therefor, that data can't possibly exist or be accurate. Ergo, any claims that climate change is happening must be exaggerated to push an agenda.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @10:34PM
We've always been at wsr with the deep state hippies trying to take our profits!
(Score: 1) by khallow on Sunday June 17 2018, @12:26PM
It's telling that you can't come up with a better argument than merely another variation of the same fallacy. Runaway should have spent a few hundred thousand dollars of public funds collecting data for years before making his post. What was he thinking? But I'm sure you did that data collection yourself, right? After all, nobody on the internet would advise someone to do something time-consuming and onerous that they wouldn't do themselves.
But I guess if we made everyone spend years on collecting data before they could write anything on the internet, it'd cut back on the crap somewhat.
(Score: 0) by Anonymous Coward on Sunday June 17 2018, @06:12AM (2 children)
Global WarmingClimate Change is now a religion, and any attempt to analyse it will bring out the fundamentalists. That's why some triggered numbnut modded you redundant.(Score: 0) by Anonymous Coward on Sunday June 17 2018, @09:12AM (1 child)
Religion in the sense that it relies on science, ah gotcha.
(Score: 0) by Anonymous Coward on Sunday June 17 2018, @12:35PM
Religion in the sense that you must have faith and any attempt to question or examine it results in a charge of blasphemy.
(Score: 2) by Entropy on Saturday June 16 2018, @04:19PM (5 children)
I guess they need to keep bombarding us with this stuff when NASA observed that the ice sheet was growing because of snowfall. Source: (NASA) https://www.upi.com/Science_News/2015/10/31/NASA-study-Net-gains-for-Antarctic-ice-sheets/9711446321864/ [upi.com]
(Score: 2) by requerdanos on Saturday June 16 2018, @04:55PM (4 children)
Even assuming a growing ice sheet, studying the phenomenon that U of A looked at here is still important.
Basically, thus:
- Sea ice acts as a buffer between waves (swells) and the ice shelf.
- There is less sea ice for whatever reason (possibly warmer temperatures, amirite?)
- So the swells more directly hit the ice shelf.
- This is bad because ice is brittle. Swells hitting the brittle ice break it.
- The broken ice breaks away, removing a barrier to glaciers' ice reaching the sea.
- So, even with a growing ice sheet, more glacial ice reaches the sea and melts, making the oceans rise a little.
Since the purpose of the study was to clear up "how much" this process contributes to sea rise, it was a great success.
The presentation in TFA was more focused on telling the world about the catastrophic destruction of pieces of ice, heralding the end of the world in galactic-scale nonsense, but the study was a good and important thing.
(Score: 0) by Anonymous Coward on Saturday June 16 2018, @08:31PM (3 children)
This is the demonstration.
So, in the perfect world of the past with the ice shelf intact, the glacial ice went... where exactly?
And in the broken real world, more water goes into growing ice sheet, and still even more goes as glacial ice into the sea... appearing from where?
Sapienti sat.
(Score: 0) by Anonymous Coward on Sunday June 17 2018, @05:35PM (2 children)
Alarmism has its issues, but willful ignorance is much worse. If you dont want to accept the findings of scientists then study up and point out any errors you see. Your "common sense" is simply not up to the taskbbn of complicated systems.
(Score: 0) by Anonymous Coward on Sunday June 17 2018, @08:14PM (1 child)
Taking stuff on faith is total antithesis of it.
BTW, every one of us who worked in real-world science or engineering, knows perfectly well how things get made up. No saints in the trade.
(Score: 2) by ants_in_pants on Monday June 18 2018, @01:32AM
things get made up in minor places, especially when there is lots of pressure to show 'expected' results.
One paper isn't enough to confirm a theory completely, but consistent results from multiple sources is pretty storng evidence. And "well they might have made it up" is never *ever* a good reason to simply dismiss a study, let alone thousands of them.
Why are climate denial people so keen on dismissing results from glaceology anyway? It's not like this is confirming or unconfirming anything about climate change, it's just saying "hey these ice sheets are breaking apart". Denying this study doesn't help your cause at all.
-Love, ants_in_pants
(Score: 1, Funny) by Anonymous Coward on Sunday June 17 2018, @05:31AM (1 child)
Great, another story about triggered snowflakes.
(Score: 0) by Anonymous Coward on Sunday June 17 2018, @05:20PM
Finally a troll is actually correct!