No, the Antarctice ice sheet is NOT shrinking.

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Expand view Topic review: No, the Antarctice ice sheet is NOT shrinking.

by harry » Thu Apr 20, 2006 7:54 am

hello all

Global warming

Is man's actiion the last straw that breaks the camels back.

The question that come to mind is with global warming do other living things get an advantage.

Increase C02 increases plant and sea life production and therfore may increase oxygen.

Increase temp should increase the rain cycle less dry areas

I could be wrong.

by Martin » Wed Apr 19, 2006 7:35 pm

Climate change skepticism, it seems to me, has a number of different sources. Firstly, there are what one might call arguments from common sense. It seems obvious that if meteorologists have trouble forecasting the weather three weeks from now, how on Earth can they claim to predict it three decades hence?

The answer to this, of course, is that scientists are forecasting not weather but average weather (i.e., climate). It is much easier to predict averages than individual values. The casino owners have no more knowledge than the gambler where the ball will fall on any particular turn of the wheel. But the owners know the averages are in their favor and can predict with mathematical precision the monthly take from each roulette table.

In fact, only three factors determine the planet's energy balance: the sun's output, the Earth's reflectivity, or albedo, and the thermal properties of the atmosphere, which are affected by the level of certain trace gases like carbon dioxide and water vapor. Reduced to its essentials, the greenhouse effect is a problem in 19th-century classical physics, and the basic theory was worked out with pencil and paper in the 1890s. To say that increasing CO2 levels leads to more heat trapped in the atmosphere is really no more scientifically controversial than saying you'll feel warmer if you put on a sweater.

The difficulty arises when you try to work out what this extra heat energy will do. Will it lead to increased rainfall, or more cloud, or higher winds? It will raise temperatures, but by how much? This is where the complex computer models and the (legitimate) scientific arguments come in—accompanied by the occasional science filmmaker!

What's required is another industrial revolution. America is rather good at these. Britain led the first (coal and steam), but America has pioneered the rest (the internal combustion engine, telecommunications, computers). Each one only adds to our prosperity, and it will be the same once again.

But there is an important difference from previous industrial revolutions. This one requires political leadership; the market on its own won't do it. To combat global warming, the world desperately needs U.S. leadership.

I am optimistic enough to believe that we won't have to wait much longer. The pace of global warming is now quickening to the point where it will soon be obvious to everyone. When you can discuss the question sitting at a pavement café in London in November in your short sleeves shirt, you just know something is up, and all skepticism becomes moot. Global warming is nothing less than a fact, and it has to be faced.

by Martin » Wed Apr 19, 2006 7:32 pm

Sunlight reaching Earth has been growing dimmer, which may seem surprising given all the international concern over global warming. At first glance, less sunlight might hardly seem to matter when our planet is stewing in greenhouse gases. But the discovery of global dimming has led several scientists to revise their models of the climate and how fast it's changing.

The good news is that pollution controls have slowed and possibly even halted global dimming during the last decade. The bad news—and the ironic twist is—is that without pollution, more sunlight is reaching Earth, revealing the full impact of global warming. Although all climate models have important uncertainties, the unsettling implication is that, with dimming fading away in many regions, global temperatures may rise even faster than most models have predicted.

by Qev » Mon Apr 17, 2006 5:55 pm

randall cameron wrote:I do not think anyone knows. I have seen research indicating that a single major volcanic eruption dwarfs the annual man-made production of greenhouse gases, and there are many other factors at work, both natural and man-made, such as the effects of particulates and cloud cover that are really poorly understood.
I've heard that before, as well, however bear in mind that 'major' volcanic eruptions are rare events, while human output of greenhouse gases is both continuous, and increasing. And that single volcanic eruption has significant effects on the planet's climate... so what is our constant input doing?
Prudence dictates that we assess the costs and benefits of significantly reducing our output of greenhouse gases, and similarly look at the costs of adapting to global warming. Either way, we need to do some serious long-range planning to mitigate the consequences and manage the costs, because warming is clearly happening.
Definitely! I doubt we'll ever turn the Earth into a twin of Venus (that's going a bit far), but that doesn't necessarily mean we're going to like how it does end up. :) And even if we aren't causing the warming, the consequences of it are not going to change any.
Even if the US signed onto Kyoto, it would only slow things down a bit. Several nations in Europe are nowhere near meeting their Kyoto targets (others are, however).
Even if they were meeting their Kyoto targets, it would only mean that they're slowing the rate that their greenhouse gas emissions are increasing, and not actually reducing the rate at which they're being emitted. Every little bit helps, though, I suppose...
Of course, at the end of the day, carbon-based fuels are going to be exhausted sooner or later whether we curb our emissions or not. That means we need to invest in new technology for large scale solar power, make a breakthrough in fusion power, or we are going to find ourselves building more nuclear reactors and wondering where to put the waste.
If we're smart, we'll put the waste right back into the reactor. :)

by randall cameron » Sun Apr 16, 2006 10:56 am

But! how much is man compared to the earth cycles and sun cycles.
I do not think anyone knows. I have seen research indicating that a single major volcanic eruption dwarfs the annual man-made production of greenhouse gases, and there are many other factors at work, both natural and man-made, such as the effects of particulates and cloud cover that are really poorly understood.

Prudence dictates that we assess the costs and benefits of significantly reducing our output of greenhouse gases, and similarly look at the costs of adapting to global warming. Either way, we need to do some serious long-range planning to mitigate the consequences and manage the costs, because warming is clearly happening.

Even if the US signed onto Kyoto, it would only slow things down a bit. Several nations in Europe are nowhere near meeting their Kyoto targets (others are, however). And emerging large economies like China, India, Brazil, Mexico and Indonesia are right to argue that the OECD were allowed to emit greenhouse gases throughout the 19th and 20th centuries on the way to building their present economies, so why should emerging economies be prohibited from doing the same, when the cost disadvantage of being environmentally friendly might prevent them from catching up?

Of course, at the end of the day, carbon-based fuels are going to be exhausted sooner or later whether we curb our emissions or not. That means we need to invest in new technology for large scale solar power, make a breakthrough in fusion power, or we are going to find ourselves building more nuclear reactors and wondering where to put the waste.

by Qev » Sun Apr 16, 2006 3:18 am

Living things can greatly affect the environment, and even the geology of planets, and humans are no different from any other living species in this regard. We sometimes forget that the world isn't some inert stage that we just act on.

by harry » Sun Apr 16, 2006 3:04 am

Hello all


I know man adds to his problems. But! how much is man compared to the earth cycles and sun cycles.


The earth through the past has done all this an much more without man's help and has gone through all these cycles,,,,,,,,, ice ages and global warming.

The earth will one day go through a nebulae as it has done in the past and most probably go through another ice age. So enjoy your global warming while it lasts.

Has anybody seen Ice Age 2,,,,,,,,,,,,,,,

by randall cameron » Sat Apr 15, 2006 1:42 pm

I do not claim to know to what extent human activity contributes to global warming, but global warming and rising sea levels are well documented, along with melting of Greenland and Antartic ice (the only big sources of rising sea levels) and more extreme weather.

A nice general interest summary appeared in Time magazine recently:

http://www.cnn.com/2006/US/03/26/coverstory/index.html

The bottom line is, regardless of the cause, we need to both look for ways to slow the process (cutting man-made greenhouse emissions being the obvious one we can control -- and this includes not just combustion, but also domestic livestock emissions), and to adapt to changes in sea level and weather patterns. Severe typhoons threaten the life and livelihood of hundreds of millions in the coastal areas of South and Southeast Asia, and the Gulf of Mexico. Rising sea levels threaten entire countries such as the Maldives, Denmark and the Netherlands, as well as places like New Orleans. And long-term climate change will disrupt and alter agricultural production and food supply across the world.

Rising sea level is pretty hard to explain unless Antartic ice is in fact melting and falling into the ocean...

by tnzkka » Thu Apr 13, 2006 2:18 pm

@ starnut: try this one: http://www.msss.com/mars_images/moc/CO2_Science_rel/

I'm sure however that we all would be better off with a more sober lifestyle.

by starnut » Tue Apr 11, 2006 3:56 am

:roll:

jfgecik, what are your REAL reasons for not believing that global warming is actually happening due to human activities? Are you afraid that if it is true, you would be forced to cut back your wasteful lifestyle of driving gas guzzlers, living in a big house burning incandescent lamps and setting your thermostat at 75 degree F year round? Do you also own shares of big oil companies like ExxonMobil that would be affected by a mandated reduction of fossil fuels?

Please get your head out of the sand! Or keep it there and don't bother the rest of us who care!

by BMAONE23 » Fri Mar 31, 2006 8:22 pm

This latest study published in the BBC news indicates that it is shrinking overall
http://news.bbc.co.uk/2/hi/science/nature/4767296.stm

by Bad Buoys » Sun Mar 12, 2006 9:35 am

The evidence of global warming is overwhelming. Anyone with proof [photos or measurements] to the contrary
is highly encouraged to post such images and citations.

But it is not the conversion of ice into seawater and the subsequent rise in sealevel which concerns me the most
[though that alone will be disasterous for the majority of us]

Rather it is the loss of the oceans' temperature buffers. Warming at the equator and cooling at the poles is what
drives our ocean currents. Those movements and temperatures are what drive our weather.

As explained 10 or so years ago; global warming is not just a matter of everything getting a uniform few degrees warmer
but more violent. The differences in our high and low pressures becomes greater and we have wider swings
in surface temperatures and much more destructive storms.

I'm alarmed at the rapid increase in the ice sheet meltings and the lack of our current mathematical modeling to grasp
let alone project the effects.

In man's defense it is still common belief that this global warming is a very long period cycle with man's input being
negligible - but again this premise is based upon modeling projections from observations of earth's past behavior.

Dinosaurs never burned millions of gallons of hydrocarbons daily injecting ALL their gases and byproducts directly
into the lower stratosphere as we do with our inceasant air travel. So we have no prior record upon which to build
a model even if we understood all of the chemical and thermal transformations which take place.

It took quite awhile to model the continuing ozone destructive reactions which chlorine molecules initiate at
higher altitudes. And that was driven by the increased size of the ozone holes which continue to increase in size
and number though the world has put severe restrictions on the manufacture and use of hydrochloroflorocarbons.

Have we already gone too far? Have we passed the point of no return such that there is no corrective
remedy before many species and millions of our own must perish from sudden loss of habitat and/or food?

Bright Side of the Road

by kovil » Sat Mar 11, 2006 6:42 pm

(Geopolitics can be such a dismal subject)

Here's the Bright Side of the Road.

As we step into a conversation in progress about evolution and the nature of consciousness in Freeman Dyson's book 'Disturbing the Universe': p247

" The penguins flipper, the nest building instinct of the swallow, the eye of the hawk, all declare, like the stars and the planets in Addison's eighteenth-century hymn, "The hand that made us is divine." Then came Darwin and Huxley, claiming that the penguin and the swallow and the hawk could be explained by the process of natural selection operating on random hereditary variations over long periods of time."

==

My reaction to that was swift;
It is not random - if I want a better eye, my consciousness strives for that, and my DNA will induce a better eye in a subsequent generation. Consciousness alters DNA.

(now of course Dyson was summarizing Darwin's point of view. He soon adds his own point of view)

==

p.249 " But I, as a physicist cannot help suspecting that there is a logical connection between the two ways in which mind appears in my universe. I cannot help thinking that our awareness of our own brains has something to do with the process which we call "observation" in atomic physics. That is to say, I think our consciousness is not just a passive epiphenomenon carried along by the chemical event in our brains, but is an active agent forcing the molecular complexes to make the choices between one quantum state and another. In other words, mind is already inherent in every electron, and the processes of human consciousness differ only in degree but not in kind from the processes of choice between quantum states which we call "chance" when they are made by electrons."


p.250-51 " There are some striking examples in the laws of nuclear physics of numerical accidents that seem to conspire to make the universe habitable. The strength of the attractive nuclear forces is just sufficient to overcome the electrical repulsion between the positive charges in the nuclei of ordinary atoms such as oxygen or iron. But the nuclear forces are not quite strong enough to bind together two protons (hydrogen nuclei) into a bound system, which would be called a diproton if it existed.
If the nuclear forces had been slightly stronger than they are, the diproton would exist and almost all the hydrogen in the universe would have been combined into diprotons and heavier nuclei. Hydrogen would have been a rare element, and stars like the sun, which live for a long time by the slow burning of hydrogen in their cores, could not exist. On the other hand, if the nuclear forces had been substantially weaker than they are, hydrogen could not burn at all and there would be no heavy elements. If, as seems likely, the evolution of life requires a star like the sun, supplying energy at a constant rate for billions of years, then the strength of nuclear forces had to lie within a rather narrow range to make life possible."

==

Here we are in danger of constructing a circular arguement, where the result implies the previous conditions. Benny Hill comes to mind in one of my favorite of his skits; where he is proclaiming
" How did God know man was going to invent glasses? But look where He put our ears !" As he dons his reading glasses and smiles.

to continue; " A similar but independent numerical accident appears in connection with the weak interaction by which hydrogen actually burns in the sun. The weak interaction is millions of times weaker than the nuclear force (often called the strong nuclear force). If the weak interaction were much stronger or much weaker, any forms of life dependent on sunlike stars would again be in difficulties."

" The facts of astronomy include some other numerical accidents that work to our advantage. For example, the universe is built on such a scale that the average distance between stars in an average galaxy like ours is about twenty million million miles, an extravagantly large distance by human standards. If a scientist asserts that the stars at these immense distances have a decisive effect on the possibility of human existance, he will be suspected of being a believer in astrology. But it happens to be true that we could not have survived if the average distance between stars were only two million million miles instead of twenty. If the distance had been smaller by a factor of ten, there would have been a high probability that another star, at some time during the four billion years that the earth has existed, would have passed by the sun close enough to disrupt with its gravitational field the orbits of the planets. To destroy life on earth, it would not be necessary to pull the earth out of the solar system. It would be sufficient merely to pull the earth into a moderately eccentric elliptical orbit."

" All the rich diversity of organic chemistry depends on a delicate ballance between electrical and quantum-mechanical forces. The ballance exists only because the laws of physics include an "exclusion principle" which forbids two electrons to occupy the same state.
If the laws were changed so that electrons no longer excluded each other, none of our essential chemistry would survive. There are many other lucky accidents in atomic physics. Without such accidents, water could not exist as a liquid, chains of carbon atoms could not form complex organic molecules, and hydrogen atoms could not form breakable bridges between molecules."

" I conclude from the existence of these accidents of physics and astronomy that the universe is an unexpectedly hospitable place for living creatures to make their home in. Being a scientist, trained in the habits of thought and language of the twentieth century rather than the eighteenth, I do not claim that the architecture of the universe proves the existance of God, I claim only that the architecture of the universe is consistent with the hypothesis that mind plays an essential role in its functioning."

I had been loosely contemplating all of this earlier this morning, after reading Dyson's chapter last night, and when clicking into the Astronomy Picture of the Day, for today, what should be today's;

[ http://antwrp.gsfc.nasa.gov/apod/ap060122.html]
(photo with explanation)

D. rad Bacteria: Candidate Astronauts
Credit: Michael Daly (Uniformed Services University of the Health Sciences), DOE

Explanation: These bacteria could survive on another planet. In an Earth lab, Deinococcus radiodurans (D. rad) survive extreme levels of radiation, extreme temperatures, dehydration, and exposure to genotoxic chemicals. Amazingly, they even have the ability to repair their own DNA, usually within 48 hours. Known as an extremophile, bacteria such as D. rad are of interest to NASA partly because they might be adaptable to help human astronauts survive on other worlds. A recent map of D. rad's DNA might allow biologists to augment their survival skills with the ability to produce medicine, clean water, and oxygen. Already they have been genetically engineered to help clean up spills of toxic mercury. Likely one of the oldest surviving life forms, D. rad was discovered by accident in the 1950s when scientists investigating food preservation techniques could not easily kill it. Pictured above, Deinococcus radiodurans grow quietly in a dish.

Easter Eggs

by kovil » Sat Mar 11, 2006 6:05 pm

Antarctic precipitation is thinner than; compared to an egg, easter egg dye. I never saw a spinning easter egg out of ballance from being painted. (although when my glasses are out of adjustment everything looks like spinning easter eggs)

There is some concern however that 16 suitcase bombs under the Greenland Ice Sheet would make ice tea of the North Atlantic and Europe.

But then some folks think that http://antwrp.gsfc.nasa.gov/apod/ap060122.html ; D.rad Bacteria: can live and have a selfdeterministic fate on Jupiter, and during impact season escape and wander the solar system. Heck they are even here on Earth now. Altered by an acute case of the Jovian Flu.

Easter Egg Suitcase Flu asides; my preferred perspective is;


Thru A Glass Onion Darkly . . .

As simple hydrogen coagulates by gravitational
attraction, random atomic motion collisions transform
into heat. Around 11 million degrees Celcius music
begins, Adagio for the Interior of the Sun, a waltz in
2/4 time, where two protons and two neutrons join
hands and helium is agreed upon.

The requisite two electrons, who ballance the protons
charge, are singing in the choir nearby, but not in
close attendance as when in a much cooler state of
repose.

The stronger the Principle of Undividedness becomes,
the higher the degrees Celcius rise. Like music, where
octaves return to the same letter note, protons and
neutrons have their preferred organization patterns at
certain numbers.
A Music of the Spheres if you will.

Some numbers are quite stable and beautiful in their
symmetry. Neon, argon, krypton, radon, xenon, helium.

Other numbers are quite fearful in thy symmetry.
Radium, uranium, plutonium.

Amongst the multitude of permutations and combinations
of adding one more proton, one more neutron; there
arise the mitigating buffers of stability and reason,
to this otherwise madness in the 'density of energy',
where matter is simply "a special state that energy
has the ability to assume" .

Cadmium welcomes neutrons without getting overheated.
Likewise, uranium hydride with zirconium hydride fuel
rods, mitigates the problem of cold neutrons
overheating the fuel if some idiot pulls the control
rods. Just ask Iranian metallurgist/physicist Massoud
Simnad, who pioneered this elegant solution to the
problem of making a safe nuclear power plant reactor
in 1957 at the Little Red Schoolhouse research design
group.

Music is energy, wavelengths combining to make
harmonies and melodies and when it sings it's
beautiful.
The flipside is like the progressive jazz of the '60's
or so, where a progression of dissonant frequencies
accumulates to produce a cachophany of competing
leading tones.

Perhaps our ultimate desire is to turn the spiggot and
regulate a flow of free energy from just a handful of
dirt.

Our sun converts 4 million tons per second into
radiant energy.
I think that should suffice for our needs!
Let us look in that direction.


jtk

by BMAONE23 » Sat Mar 11, 2006 4:45 pm

Could increased percip. levals at Antarctica increase the weight at the pole to an extent such that it might then pull the earth out of its current 23deg tilt?

Looking at the Ice and Seeing Red not Blue

by kovil » Sat Mar 11, 2006 2:22 pm

<One portion is shrinking, but another (much larger) portion of the sheet is growing so much that it more than offsets the loss of ice from the first portion. >

If you mean by this statement that the higher elevation central portion of the Antarctic Ice Sheet is receiving more precipitation than the peripheral areas are losing in calving and melt; then I disagree with you.

There is a presumptive theory that as global warming occurs the moisture content of the atmosphere rises and precipitation amounts will increase in Antarctica, partially ballancing any peripheral losses. The peripheral losses will still outweigh any precipitational gains tho. It is merely a mitigating event.

Planetary overall ice formations are in an accellerating melting phase,
they are certainly not in an accumulating or growing phase. All studies show glaciers thinning, receeding, and diminishing; from Alaska, the Andes, Africa, Tibet, Europe, Australia/New Zealand, Canada.

Do you drive an SUV? Or are you just in denial?

by jfgecik » Sat Mar 11, 2006 11:54 am

I see that my opening post for this thread was not refuted [thank you!], though it was countered by some extraneous material -- a typical tactic of ultra-liberal hand-wringers who want to "cover" for the embarrassed writer of the faulty APoD description (by changing the subject). This thread is not about Greenland, global warming, and the other irrelevant matters that were mentioned. It is about the Antarctic ice sheet growing, as a whole.

At least one of you geniuses should have realized that the Antartic mass is taking on some of the water that is melting elsewhere. But no, that would have been too optimistic an idea to even occur to you prophets of gloom and doom.

Well, you worry-wart liberals tend not to live as long as the average person (being more likely to be done in by AIDS, illegal drugs, drunk driving, etc.), so I'm afraid that you probably won't be around enough years to realize that this whole business (melting, warming, etc.) was never anything to worry and whine about.

God bless you.

Re: Ice Bergs in Hong Kong Harbor

by ta152h0 » Sat Mar 11, 2006 12:34 am

[quote="

In the 1960's somebody had an idea to tow an iceberg to Los Angeles to help solve the drinking water shortage. Only 1/2 of it would melt in the two year trip from the antarctic.



Yeah, I remember now. it was an article in Popular Mechanics so long ago.

by BMAONE23 » Fri Mar 10, 2006 3:01 pm

It could have an affect on the temperature of the warmer ocean water causing a slight cooling along the equator as it passes. Probably no net effect though. But???

Ice Bergs in Hong Kong Harbor

by kovil » Thu Mar 09, 2006 5:19 am

Sherlock olde chap, it was a grumpy morning; the new GRB is agitating the high pressured quarks in the sun and jupiter and everyone is overly dogmatic today as a result, so please don't feel reprimanded too harshly, it's just the life and times of the poster children, of which I am one too.

I've never worked in a bureaucracy, but if things get done and figured out as fast as they do on this board, ?

In the 1960's somebody had an idea to tow an iceberg to Los Angeles to help solve the drinking water shortage. Only 1/2 of it would melt in the two year trip from the antarctic. I wonder what would tow B15a? That would make a boat load of snow cones !
On a second thought about it this morning, it seemed like a more feasible idea these days than it did then. At least we would get some nice water out of the deal of the icebergs falling off.

I wonder how much it would cool off the prevailing breeze on a hot day in Santa Monica to have 3400 cubic kilometers of ice anchored to Catalina Island ! or jammed inbetween LA and Catalina in the channel ! hahaha
Wouldn't it be a hoot if Cristo or somebody did it for a lark !
He could carve it to look like a big surfboard !
It's long enough you could land the space shuttle on it in a pinch.
And cool enough to take off from too.

One thing about icebergs when they melt the freshwater melt stays on the seasurface, if the temperature doesn't carry it lower and make it mix and dilute the sea. I can see it going both ways here, either floating on top of the denser sea water, or sinking and mixing as it is much colder.
I vote for it to mix a little due to cold sinking, but 70% of it to remain near the surface, top 200 ' of sea surface over medium term.
Ships will ride lower in the water, 2% lowriders near the bergs.

I wonder how long it would take to mostly disappear by melting.
A heat flow diagram makes me feel it could be over a decade, and no where near 1/2 would be lost in the tow. Maybe that was to include chunks breaking off, and if they actually got 1/2 of it there, that would be a big success.

by rummij » Thu Mar 09, 2006 12:33 am

[quote="Qev"]Actually, floating ice, when it melts, really should raise the sea level, albeit only slightly compared to non-floating ice melt. Sea water is more dense than fresh water, and ice is (primarily) composed of fresh water. As it melts, it dilutes the sea water, lowering its density. No?

Or another way of looking at it, one tonne of floating freshwater ice will displace one tonne of seawater. The density of liquid fresh water is 1 tonne per cubic meter, while the density of liquid salt water is somewhat higher (by roughly 3% or so). This floating tonne of ice, then is displacing less than a cubic meter of seawater. However, when the ice melts, it will become a cubic meter of freshwater, which is a higher volume of water than it was originally displacing as floating ice. Thus, an increase of sea level.

Someone tell me if that makes sense. :)[/quote]


Kinda not really. Water always has the same displacement in respect of other water around it, whether it's liquid or ice. If a piece of ice is floating, the part that is above the surface will represent its excesss volume as a result of it being frozen. When floating ice melts, the water level will stay the same.

When pack ice melts, ie. ice resting on land, then you will get a rise in water level. This is why a complet meltdown of the *Arctic* polar ice cap would have no effect on sea levels. The pack ice resting on top of Greenland and Antarctica, on the other hand, would.

melting ice

by ta152h0 » Wed Mar 08, 2006 9:07 pm

Another thought not found here is how much of the melting ice becomes water vapour being added to the atmosphere and carried and deposited on land masses, not directly affecting ocean water levels ?

by Qev » Wed Mar 08, 2006 8:29 pm

Actually, floating ice, when it melts, really should raise the sea level, albeit only slightly compared to non-floating ice melt. Sea water is more dense than fresh water, and ice is (primarily) composed of fresh water. As it melts, it dilutes the sea water, lowering its density. No?

Or another way of looking at it, one tonne of floating freshwater ice will displace one tonne of seawater. The density of liquid fresh water is 1 tonne per cubic meter, while the density of liquid salt water is somewhat higher (by roughly 3% or so). This floating tonne of ice, then is displacing less than a cubic meter of seawater. However, when the ice melts, it will become a cubic meter of freshwater, which is a higher volume of water than it was originally displacing as floating ice. Thus, an increase of sea level.

Someone tell me if that makes sense. :)

Ice Sheet Meltdown

by sherlock » Wed Mar 08, 2006 8:05 pm

Well, I must say, my first day at trying my hand at posting here was both humbling and educational. I suppose I tend to spout off my first thoughts without thinking it completely through.
Of course, surface ice meltdown didn't occur to me.
And, oh yeah, that thermal expansion thing slipped by me too.
I will do my level best to not bore everyone with any more laymen postings. Thanks for the spanking.

Re: Antartic Ice Sheet

by mikhail » Wed Mar 08, 2006 7:50 pm

sherlock wrote:So it's melting/So it's swapping ends
Wouldn't the amount of water melting off be offset by displacement of the ice? Take a glass of ice water...does the level rise after the ice has melted?
That would depend on the temperature of the water. Water contracts with falling temperature (like most other things), until it hits 4 degrees (C) when it starts expanding again. So ice has a greater volume than cold water. I can't believe you don't know that - don't they teach anything in schools these days?

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