Norwegian Seafloor Holds Clues To Antarctic Melting (bbc.com) 41
Antarctica's melting ice sheet could retreat much faster than previously thought, new research suggests. The BBC reports: The evidence comes from markings on the seafloor off Norway that record the pull-back of a melting European ice sheet thousands of years ago. Today, the fastest withdrawing glaciers in Antarctica are seen to retreat by up to 30m a day. But if they sped up, the extra melt water would have big implications for sea-level rises around the globe. Ice losses from Antarctica caused by climate change have already pushed up the surface of the world's oceans by nearly 1cm since the 1990s. The researchers found that with the Norwegian sheet, the maximum retreat was more than 600m a day.
"This is something we could see if we continue with the upper estimates for temperature rise," explained Dr Christine Batchelor from Newcastle University, UK. "Although, worryingly, when we did the equations to think about what would be needed to instigate such retreat in Antarctica, we actually found there are places where you could get similar pulses of withdrawal even under the basal melt rates we know are happening at the moment," she told BBC News. The findings have been published in the journal Nature.
"This is something we could see if we continue with the upper estimates for temperature rise," explained Dr Christine Batchelor from Newcastle University, UK. "Although, worryingly, when we did the equations to think about what would be needed to instigate such retreat in Antarctica, we actually found there are places where you could get similar pulses of withdrawal even under the basal melt rates we know are happening at the moment," she told BBC News. The findings have been published in the journal Nature.
Gentlemen, we have a problem... (Score:1)
climate change have already pushed up the surface of the world's oceans by nearly 1cm since the 1990s.
1 cm over 33 years? How do you even measure such a small change in sea level when the sea is constantly rising and falling by way more than that due to tidal forces and simply wave motion of water?
Right now (5:00 AM), it's 49F outside here in hot sunny Arizona. March this year was the coldest March on record during the past 30 years for this area. Global warming?
Oh, but climate change is real. Trust the science!
Re: Gentlemen, we have a problem... (Score:1)
How fucking daft do you have to be to not understand averaging. Take measurements a few times a day at different tides, slightly offshore. Or take more measurements at closer to shore to round out differences by waves.
Then, watch this magical shit, you "average" those values over a time period and if those averages grow, then the sea rises.
I don't know which is worse, trolls are this lame or some people might believe this dog shit logic.
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How [Re: Gentlemen, we have a problem...] (Score:2)
Actually it's a little harder than you imply; you need to take measurements at multiple places around the globe to eliminate local effects, and the key is to take a LOT of measurements to average out noise. But, overall, yes, right. https://www.climate.gov/news-f... [climate.gov] for more.
These days, of course, we can measure satellite laser- and radar altimeters (Topex-Poseidon [wikipedia.org] and its follow-on satellites.
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How do you measure a small change in sea level?
Very carefully. Step 1 is to find a geologically stable shoreline. This is actually quite hard to do. Puget Sound is completely unsuitable, parts of it are going up, and other parts are sinking due to geology. The West Coast is entirely unsuitable due to the Cascadia subduction zone and the San Andreas fault.
The Northeastern US is unsuitable due to isostatic rebound from the Atlanteans melting down the previous ice sheets.
The Southeastern US is subsiding due to
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Well, one way to do that is to measure somewhere there are no tides.
What?? No tides? Yep, blew my mind too. But in Aruba, for instance, there are no tides. Where it is located there is nothing to inhibit the movement of water, and being near the equator it does not see much of the direct tidal bulge effect from the moon, so no real tides (at least that's how I understand it). So in calm seas, inside a harbor, no wave action, no tides... you can measure sea levels pretty simply and accurately.
Right now
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>But in Aruba, for instance, there are no tides
Wow, learn something new every day!
https://www.tidetime.org/centr... [tidetime.org]
Highs and lows of tens of cm, while New York Harbor for example is more like 300 cm.
https://marineweather.net/tide... [marineweather.net]
Re:Antarctic is in the southern hemisphere (Score:5, Informative)
Norway is in the northern hemisphere, somebody needs to figure that out
They're simply using examples of glacier retreat from thousands of years ago near Norway as a basis to compare/contrast/predict retreat today near Antarctica (probably to tune models). Thought that was pretty clear, even a little more so in TFA, but, then again, I can read. :-)
The evidence comes from markings on the seafloor off Norway that record the pull-back of a melting European ice sheet thousands of years ago. Today, the fastest withdrawing glaciers in Antarctica are seen to retreat by up to 30m a day.
Re:Antarctic is in the southern hemisphere (Score:4, Informative)
Very good article. I am glad that they have been able to establish that the Ice sheets have been melting for thousands of years
The rise in sea level affiliated with the glacial retreat after the most recent ice-age glaciation is well known.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Saying that they "have been melting for thousands of years" is a little inaccurate. What you meant to say is that the glaciers "had been melting thousands of years ago"
and at some times up to 600m a day.
That part is the new result.
I was under the impression that most believed that they have only begun melting in the last 100 years.
You had been under the wrong impression. The fact that the advance and retreat of glaciation during an ice age is associated with sea level changes has been known for hundreds of years, pretty much ever since Louis Agassiz popularized the term ice age.
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Well, sort of. But actually glaciers HAVE been melting for thousands of years, but they've also been growing. Different seasons, different places. It's a complicated argument, and no simple answer is going to be correct. One can talk about averages, but even there it depends on just how you pick the samples you average.
This is a case where you HAVE to trust the experts, because nobody else has sufficient insight. The problems are that the experts are often wrong, because they don't have sufficient insi
Average [Re:Antarctic is in the southern hemis...] (Score:2)
Well, sort of. But actually glaciers HAVE been melting for thousands of years, but they've also been growing. Different seasons, different places.
True enough. Even one particular glacier will both grow (by accumulation of snow in winter that does not melt in summer) and also melt (as it flows to the sea, as well as the melt occuring on the pieces after they break off into the sea.) What matters to sea level rise is the global average over time, which is much less dependent whether on a single spot at a given moment has a high melt rate.
This is a case where you HAVE to trust the experts, because nobody else has sufficient insight. The problems are that the experts are often wrong, because they don't have sufficient insight either (though they can often put error bars around things) and also they're often wrong.
Science tends to be a process of eliminating older hypotheses in favor successively better hypotheses supported by
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Funnily you do not need to be an expert to see that glaciers are melting.
You only need:
a) live close to one
b) looks out of the window from time to time
Simple, isn't it?
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600m a day? ... was it 270m or 170m? Somehow I memorized the x70, but now I think I remember 230m.
Perhaps when a collapsing iceberg on top of a rock caused a Tsunami.
The difference in sea levels during the previous "ice age" and now, is less than 300m
Point is: 600m per day is idiotic. Perhaps you wanted to write 600mm, but then it would be more prone to write 6m ... up to you.
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Norway is in the northern hemisphere, somebody needs to figure that out
The process of water melting works the same in both hemispheres, somebody needs to figure that out.
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What? No way, water melts the opposite direction. Duh.
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What? No way, water melts the opposite direction. Duh.
If it helps you to better comprehend what is going on here, water transitions from its solid state to its liquid state in exactly the same way in both the northern and southern hemisphere. What is peculiar here is the fact that you seem to think it doesn't.
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What? No way, water melts the opposite direction. Duh.
If it helps you to better comprehend what is going on here, water transitions from its solid state to its liquid state in exactly the same way in both the northern and southern hemisphere. What is peculiar here is the fact that you seem to think it doesn't.
*takes deep breath*
Wooooooosh.
Ah, that felt good. Some of the old memes are good memes.
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Norway has territory in Antarctica too.The first man to discover the South Pole was Amundsen.
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Re: (Score:2)
No evidence. That "somebody did it" isn't proof that anybody in particular did it. E.g. how do you know it wasn't the Saudi's? It would take somebody with a bit of muscle, a bit of clout, and a bunch of cash, but that doesn't limit things very much.
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You do realize that real things continue to happen whether or not there is some political spin machine spoon feeding you (mis)information about it, right?
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In fact, the historical record shows sudden spikes of temperature and CO2 about every 120k years.
This happened at least 30 or 40 times previously (depending on when you say the signal data is clear from the 'noise') about every 120k years.
The last was around 120k years ago, so we're due.
So AGW enthusiasts must explain how ...just at the right moment
- the previous periodic cycle is entirely suppressed and replaced by something that looks almost identical
-
- and whatever natural feedback mechanism sorts it out
Re: Just checking... (Score:2)
Re: (Score:2)
Sure about that?
https://journals.sagepub.com/d... [sagepub.com]
" Abstract
More than 90,000 accurate chemical analyses of CO2 in air since 1812 are summarised. The historic chemical data reveal that changes in CO2 track changes in temperature, and therefore climate in contrast to the simple, monotonically increasing CO2 trend depicted in the post-1990 literature on climate-change. Since 1812, the CO2 concentration in northern hemispheric air has fluctuated exhibiting three high level maxima around 1825, 1857 and 1942 the l
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Oh and:
https://climatediscussionnexus... [climatedis...nnexus.com]
âoeThe elements relating temperature to future CO2 and CH4 concentration, and ice volume to future CO2, are significantly positive at the 1% level and that relating ice to future CH4 is significant at the 5% level. On the other hand, the effects of CO2 and CH4 on future temperature are statistically insignificant at the 10% level, and the effect of CO2 on future ice volume is insignificant at the 5% level.â
In short, temperature influences CO2 levels but CO2
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AGW proponents insist climate is chaotic,
No they don't. In General TheyAreMoreSmarterThanYou.
We all learned in school about "Milankovitch cycles". I mean: I went into school 1973, I think. 1977 I switched from primary school to high school/gymnasium. Somewhere around that time I learned basic science - science got separated into biology, physics and chemistry 2 years later.
No idea what you learned in school. It looks like you learned to make up a "false argument" and challenge others to defute your "false a
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Ad hominem after ad hominem. Always the best way to win a debate about fact, yeah? Is that what you learned in 1973?
FWIW we're the same age, so don't think we come somehow from different contexts.
Maybe argue the facts instead of spending all your time dissecting idiom?
Yes, 'personally' and 'what I believe' are syntactically redundant.
"Personally" doesn't mean I physically witnessed something...clearly English isn't your first language; I'd guess only a German would be arrogant enough to try to attack some
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Pointing out that you are an idiot and/or a lier or both, is not an ad hominem :P
https://en.wikipedia.org/wiki/... [wikipedia.org]
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Hilariously, that is EXACTLY an ad hominem.
So...German you are: absolutely certain of yourself,, no matter how ridiculously wrong.
Thanks for confirming.
could (Score:2)
Could, might, may, possibly, maybe, conceivable... Or, might not.