Ross Ice Shelf could 'collapse quickly'

[donsu]

http://www.news.com.au/story/0,23599,20840754-23109,00.html


SCIENTISTS working in Antarctica fear the Ross Ice Shelf, an ice platform the size of France, could collapse quickly and trigger a rapid rise in sea levels.

A research team drilling in the frozen continent has recovered three million years of climate history, New Zealand newspaper The Press reported today.

-snip-

"If the ice shelf goes, then what about the West Antarctic Ice Sheet? What we've learnt from the Antarctic Peninsula is when once buttressing ice sheets go, the glaciers feeding them move faster and that's the thing that isn't so cheery."

Antarctica stores 90 per cent of the world's water, with the the West Antarctic Ice Sheet holding an estimated 30 million cu km.

In January, British Antarctic Survey researchers predicted that its collapse would make sea levels rise by at least 5m, with other estimates predicting a rise of up to 17m

-snip-

"We know from the Larsen Ice Shelf (which collapsed on the Antarctic Peninsula in 2002) that they go extremely quickly," he said.
-------------------------

sigh

[karlrschneider]

1. "Antarctica stores 90 per cent of the world's water..."??

Shouldn't that be 90 percent of ...FRESH water?

...

[bennywhale]

5. Whatever it is, what are we going to do about it.

Rather than pick up on a typo or missing word, lets discuss what to do

[karlrschneider]

7. The ice is already floating on water. It can NOT raise sea levels.

...

[Dora]

9. I never took physics, but I drink iced drinks....

In a glass of liquid with ice in it, the floating ice has a certain amount of mass above and below the water line. As the ice melts, the water line rises.

How does the ice shelf collapsing differ from my example? Thanks.

[karlrschneider]

17. Maybe you should drink something with more ice and less alcohol.

The water line does not rise as the ice melts.

[Dora]

35. Well, then. Color me duly scolded.

Everyone seems so nasty on DU these days. I present a disclaimer, "I never took physics," and you give me a spoon of shit in return.

A teachable moment turned into snark points.

:eyes:

Added on edit: And while I'm cutting back on my non-existent alcohol consumption, you could down a chill pill or two of your own.

[karlrschneider]

41. Well, you admitted you never took physics and then made some effort

to explain how you knew better anyway. That's what punched my button. I apologize.

[Czolgosz]

91. I have had plenty of physics. I have also had plenty alcoholic beverages with ice.

I get the impression that you have insufficient experience with either if you don't understand how an ice shelf the size of France breaking away from Antarctica would lead to a rise in sea levels.

EXPERIMENT:

Get yourself two beverages -- for you, I'm recommending that they be alcoholic. Get one comparably sized ice cube for each beverage. Put one ice cube in your first beverage intact. Break a fragment off the other ice cube and put the broken ice cube plus the ice fragment into the second beverage. Please report back on the fate of the fragment chipped off the ice cube.

BONUS QUESTIONS:

How much of the frozen water mass comprising the Ross Ice Shelf is currently above the sea level?

If the Ross Ice Shelf breaks away from Antarctica and melts into the Ross Sea or other contiguous body of water, then how much of that no-longer-frozen water mass will be above the sea level?

[Xithras]

187. Irrelevant.

Ice floats because the density of water lowers as it transitions into a frozen state. While a small percentage of floating ice does extend above the waterline, the full mass and volume of the frozen water is still being supported by the liquid water below. As the ice transitions back into water, it becomes denser reducing its overall volume to an amount equal to that displaced by the part of the ice originally below the water line.

But don't take my word for it. Get an ice cube, a pen, , a glass, and some pure water. Test it out yourself, but don't forget to cover the top of the glass to prevent evaporation. The water level will NOT change.

[Warren DeMontague]

40. Riddle me this, batman..

what you're arguing may be true- in a glass of scotch, for instance.

However, consider the surface of the Earth- a sphere. Consider all the water that is held in the poles in solid form. Then consider when it melts, it will no longer be held in solid form at the poles, yet will spread out equally in the world's oceans. Also consider that some of that ice is not floating "in" water, but is on land, like Antarctica.

[karlrschneider]

43. My complaint was that the article as written implied that the Ross

shelf breaking away would raise sea levels...which is not true since it's all in the ocean already.
Obviously ice that is sitting on top of land is a different story such as the Antarctica continent
and Greenland.

[hootinholler]

92. The shelf is just that, a shelf...

Unlike the Arctic ice cap, it is not floating but a huge shelf anchored to and cantelevered from the Antarctic land mass.

Unless I've totally missed the big picture here.

-Hoot

[Czolgosz]

93. The Ross Ice Shelf is "in the ocean already"? Someone should warn this guy before he drowns.

While we're at it, we should alert the nice folks at the McMurdo Station:

[slackmaster]

82. Best. Comeback. Ever.

:toast:

[ecstatic]

97. yeah, that was funny!

Harsh, but funny! :rofl:

[Czolgosz]

101. It would be funnier if it were not laughably incorrect.

[LSK]

111. however, the ice in a drink does not float on top of it

[karlrschneider]

122. Where -does- it float?....on the bottom?

:eyes:

[LSK]

124. within the liquid, not on top of it

Most of the ice floats within the liquid, NOT ON TOP.

Your argument is apples to oranges.

Quite trying to know everything. Sheesh.

[karlrschneider]

126. Okay, take that Vodka Tonic in the last picture and add water right up to the

rim of the glass. When the ice melts, the liquid will be BELOW the rim.

[LSK]

127. apples to oranges

As most icebergs float ON TOP OF THE OCEAN. Which is not the case in your glass of alcohol with ice "experiment".

http://www.geocities.com/yosemite/rapids/4233/floating.htm

In addition, from what I understand, part of this Ice Sheet in question is on land. From what I understand, it will slide into the ocean.

[karlrschneider]

130. Are you unaware that 80 percent of icebergs are BELOW the surface?

sheesh...

[LSK]

131. does this look below the surface?

These are the same how exactly???

Take the ice in that glass and pile more on top of it about 1/3 of the way past the height of the glass and maybe then you will have the same situation.

[karlrschneider]

135. The helicopter obviously doesn't.

You can dump more ice in that glass and it will obviously spill out the liquid. Duh. Here:

[LSK]

138. who's talking about the helicopter??

You are starting to sound absurd with your obsession to try to win this argument.

Why bother arguing with you anymore? I'm done.

Bye.

[leftchick]

143. He is Ignoring what the scientists are actually worried about

It is not the ice in the water it is the Glaciers waiting to follow the broken ice shelves. I posted a couple of links that he seems to want to ignore. They blast his first assumption of what they are saying out of the glass of water. Along with all of these silly sidetrack arguments defending it.

:eyes:

[QuestionAll...]

144. give it up, karl! omg!

you're dead fuggin Wrong! :rofl:

egos!
omg! no wonder we're in such a collective mess around the globe.
Anything to keep that rooster proudness intact.

[longship]

149. Pshaw!!! Yes, it does.

As everybody knows, almost all of an iceberg is below the water. The reason is two facts from physics.

1. Ice is less dense than liquid water.
2. The Archimedes principle.

Because of these facts, ice floats and displaces precisely the same volume of water equal to the ice's mass. Since ice density < water, part of the ice does stick above the surface. QED.

There are some people here who need to take some basic science classes.

[SlavesandBulldozers]

153. that's correct.

i remember it from Mr. Wizard.

[longship]

20. Not true.

I did take physics (B.S. degree). The water level does not rise. The ice is partially above the water surface because ice has a lower density than liquid water. The water level remains the same.

Let's get this correct. Ross ice shelf melting will not increase water levels, but the subsequent sliding of the West Antarctic shelf into the ocean *will*.

[Dora]

36. Thank you.

I feel better informed now. I guess my post was based on assumption rather than observation.

Thank you for clarifying.

[ashling]

39. Whether or not it affects sea level

wouldn't it affect the salinity of the oceans?

[karlrschneider]

45. Yes, it would dilute their salinity. Which could alter currents such as the

Gulf stream.

[FedUpWithIt All]

89. It will not rise as long as it remains ice....

isn't the issue that breaking off may cause it to move to a slightly warmer location and thus melt?

I do know melting sea ice will change the current strength and cause land ice to increase ly melt. This would clearly raise ice levels. What i am not sure is whether the breaking off is concerning because it may lead to this.

[Czolgosz]

99. You are mistaken.

Take an glass with water in it. The drop in an ice cube. The water level rises because the ice cube displaces water.

The Ross Ice Shelf is not currently "in the water" - an ice shelf is not the same thing as an iceberg.

Even leaving aside this obvious mistake about the water displacement, Dr. Peter Noerdlinger has a good and informative paper which explains how you would be incorrect even if we factor out the enormous amount of water displacement.

Do you not understand how large an ice mass we are discussing? The Ross Ice Shelf is the bit near Texas on this superimposed map:



Are you truly failing to grasp how the Ross Ice Shelf's separation from Antarctica would raise the sea level or are you teasing?

[karlrschneider]

108. You are rigging the 'experiment.' You want to cheat by filling the glass

(the sea) and THEN plonk a big ice cube into it. The honest way to look at it is to assume (as is the case) the ice is floating, as the Ross ice field is doing. Obviously, frozen water that is not in the water already is a completely different matter.

[Czolgosz]

112. If the Ross Ice Shelf is "floating" does it rise and fall with the tides?

The answer is no.

If it doesn't rise and fall with the tides, it is truly floating?

Again, the answer is no.

The ice shelf is supported by its buoyancy to a degree, but it is not entirely supported by its buoyancy. What other force supports the Ross Ice Shelf?

The answer is its connection to the land.

If this support that the Ross Ice Shelf receives from its connection to the land fails, will the ice shelf fall up, will it fall sideways, or will it fall down?

The answer is it will fall down.

If the ice, which was formerly supported in part by its connection with the land falls down deeper into the water, what will become of the water the formerly occupied the space which the ice shel (now just an iceberg) occupies?

It will be displaced.

How will that water displacement manifest itself?

Rising sea levels.



Will I have to explain evolution next?

[karlrschneider]

123. See the link below:

"Tides flow in the ocean water cavities under the large ice shelves surrounding Antarctica. Most of the shelf responds just like a free floating block of ice or boat on the ocean surface, going up and down in phase with the underlying tide."

http://www.esr.org/antarctic/ice_shelf_tides.html

[Czolgosz]

132. The link confirms what I was telling you

"A small shelf, like the AIS has a fairly simple tide: the ice shelf just goes up and down roughly in phase over the entire shelf.

A larger, more complicated region like the FRIS shows the flexing of the ice shelf as the tidal waves propagate around underneath it.

The RIS (Ross Ice Shelf), like the FRIS, is large enough to show the flexing of the ice shelf as the tidal waves propagate around underneath."

The Ross Ice Shelf is so large that waves propagate underneath it. Obviously, it is not a free floating mass, is it? If it is not free floating, the non-floating portion of the Ross Ice Shelf will displace water when it sheers away from the land, won't it? That water displacement will affect the sea level in an amount likely be measurable in feet, not inches.

[karlrschneider]

134. Fine. You are a genius, I am a moron.

End of discussion.

[Czolgosz]

137. You aren't a moron. You were just browbeating people on a scientific issue where you were incorrect.

[Xithras]

190. What? Where did you get that?

The fact that waves propagate beneath it is irrelevant to the question of whether its floating. Waves propagate beneath EVERYTHING in the sea...except ice grounded into the bottom which allows no water passage underneath. The only relevant question is whether the shelf rises and falls with the tide. If it rises with the tide, it's level is obviously being supported by the water. A look at both the text and the associated video confirms that the RIS does in fact rise and fall with the tides, and that it is already floating.

Your discussion about the non-floating portion of the ice shelf is irrelevant to the discussion. The point of contention is whether floating sea ice raises water levels.

Nobody, that I have seen, has disputed the argument that the melting of grounded ice raises sea levels. Obviously it does, and anyone with a 1st grade education can see that.

[Czolgosz]

192. "Tides flex the ice shelf near the grounding line." The ice shelf is not free floating.

There is a grounding line to all ice shelves, and downstream of the grounding line, there is a hinge line. The ice downstream of the hinge line does not break free of the grounded portion of the ice shelf and free float above the extra salty ice shelf water; the ice shelf is supported by both the superbuoyancy of the ice shelf (superbuoyancy due to the extra density of the extra salty salt water below) plus the structural support of the ice shelf. It is inaccurate to think of an ice shelf as an ice berg, and it will underestimate the rise in sea levels to neglect to account for the different densities of the super-salty ice shelf water and the frozen fresh water comprising ice shelf.

[longship]

152. Repeat after me:

"The Ross Ice Shelf is ocean pack ice, so it is floating."
"The Ross Ice Shelf is ocean pack ice, so it is floating."
"The Ross Ice Shelf is ocean pack ice, so it is floating."
"The Ross Ice Shelf is ocean pack ice, so it is floating."
"The Ross Ice Shelf is ocean pack ice, so it is floating."


Got it?

[Czolgosz]

172. Repeat after me: "The water underneath the Ross Ice Shelf is ultra high

salinity shelf water but the water frozen in the Ross Ice Shelf is fresh water and this fact counteracts the Archimedes principle, and the Ross Ice Shelf is like other ice shelves in that it is connected to the land and it is fed by glaciers resting on land and so the upstream portion of the ice shelf is also resting on the land, and like other ice shelves the Ross Ice Shelf has a grounding zone (except that the Ross Ice Shelf isn't exactly like other ice shelves in that its GZ is enormous) and a hinge-line and so it is erroneous to think of the Ross Ice Shelf as if it were a huge iceberg floating in fresh water."

[longship]

177. Here's an experiment that will prove you wrong.

Try a little kitchen experiment.

Make some salt water. Make the salinity as high as you can so to maximize the difference in density. However, do not supersaturate the liquid. Accurately record the volume of liquid and its mass. Divide mass by volume to determine the density. Pour salt water into a container and mark the level as #1.

Measure the mass of some fresh water ice. The mass should be large enough to substantively change the level of the salt water and small enough so that it still floats in the container of salt water.

Put the ice into the salt water. It should float. Quickly mark the level as #2.

Optional: Let the ice melt. Mark the level again, #3.

Measure the volume of liquid required to raise the level from level #1 to level #2. You can do this with fresh water since we only need to know the volume. Multiply this volume by the density of the salt water calculated above. The result is the mass displacement of the ice. This should exactly equal the mass of the ice measured above.

That's the Archimedes principle.

The only question that remains is: Is there a difference between marks #2 and #3?

Running this as a thought experiment says, "No."

BTW, I am aware that part of the Ross ice shelf sits on terra firma. Obviously that part melting *would* result in increase water levels. The question is, is that part sufficiently large to substantively increase the ocean levels?

[karlrschneider]

182. Actually, I'm pretty certain the shelf sits on top of water only BY DEFINITION

There really isn't any other sensible way to describe its size, dimensions and boundary. If some of it were on solid ground, where would they 'draw the line'? Why would not the entire Antarctic continent be "part" of it if the definition were that arbitrary?...it makes no sense geophysically, geographically or scientifically.
edit for minor spelling mistake

[Czolgosz]

186. No. By definition the ice shelf covers both land and sea. Ice shelves have a "grounding zone"

and this grounding zone is an area where the ice shelf is supported by terra firma, not by the ice's buoyancy. Also, ice shelves have a hinge-line which demarks the area of the ice shelf which is immobile and the part of the ice shelf which is supported in part by the ice structure and part by the ice's buoyancy (and remember, it is superbouyant because of the extra salinity of the water below -- the water below the ice shelves is substantially more salty than general sea water). The ice shelf doesn't beak and flow up and down on the tide (in fact, that is the action we fear); the ice shelf is immobile upstream of the hinge-line and it flexes with the tide downstream of the hinge-line. It seems as if you want to define the ice shelf to include only the portion of the ice shelf downstream of the hinge-line (i.e., you want to cut out the "shelf" part of the "ice shelf"), and that is simply not how an ice shelf is defined in the scientific literature.

[longship]

197. Thanks for this clarification. Is this summary correct, then?

It seems like we have a much more complex situation than is described in the press.

Should our conclusions be that the water level will increase due to a couple of mechanisms.

1. Some of the ice shelf is not "free floating". It's either resting on terra firma or some other support. Are we to presume that this also substantially includes the ice inside the hingeline?

2. When the lower density of fresh water ice melts in salt water it can contribute to a level increase in proportion to the relative masses of the two substances and their density difference. Of course, with so much salt water in the oceans, this is likely to be small.

Is this a correct now?

[Czolgosz]

188. Here are pictures of the very experiment you describe. They confirm my point.

ice floating in a saline solution --- ice melted, note the liquid level

---

[longship]

195. An explanation of what's happening here.

About Archimedes principle...

The Archimedes principle applies only to the amount of water displaced by the solid floating on the water. Once the ice melts, it's a matter of simple combination of two different solutions and Archimedes is not longer applicable.

About the rise in level in the graduated cylinder...

This is from the lower density of fresh water as opposed to salt water. Yes, there is an increase in level in your graduated cylinder due to the lower density fresh water ice melting in your experiment.

However, one also has to consider the ratio of volume of added fresh water (due to the melting ice) vs the volume of salt water. In your test, the ratio was much, much higher than it would be in the ocean. The reason why there will be little change in the ocean level is because there is a whole globe full of salt water and a *relatively* small amount of fresh water. It will increase the water level, but it will not be significant.

Are you happy with this characterization? Or am I still missing something?
Also, see my post above.

[Mr_Spock]

145. I was wondering about that

They talk about the Ross ice shelf melting and causing a sudden rise in sea levels, but that would only be true if the West Antarctic shelf which is above sea level slid into the ocean - as you have said.

I find articles like that somewhat deceptive - though I am well aware of the danger that increasing the flow rate of the glaciers might have.

[Tesha]

30. Nope. As the ice melts, the liquid level remains the same

(So long as the liquid has approximately the same density
as water, so not too much alcohol or sugar.)

[karlrschneider]

38. It doesn't matter, as long as it's denser than the ice.

Since when ice melts, the total volume decreases.
Of course, if it's less dense the ice won't float anyway.

[Tesha]

66. If you're studying the question of whether the liquid level changes...

If you're studying the question of whether the liquid level changes,
then the answer is "Yes, the liquid level always changes unless its
starting density is the same as the liquid that will be evolved from
the ice cubes when they melt."

If the liquid is more dense than the water that will be evolved
from the ice cubes (becuase, for example, it contains lots of
sugar), then the liquid level will rise as the cubes melt because
the evolved new water from the ice cubes will occupy more volume
than the volume of the heavier liquid that was originally displaced
by the ice.

If the liquid is less dense than water (because it contains lots
of ethanol, for example), then as the ice cubes melt, the liquid
level will drop because the melted water will take less volume
than the volume of light fluid that was being displaced to float
the ice.

This is easy to test. Next time you pour yourself a Scotch on the
Rocks, add enough liquid water to just make the ice cubes float.
Then mark the current liquid level in the glass. Wait (and mix
and drink a Martini while you do so). When the ice cubes have
all melted, note the new liquid level in the glass. If you
originally just barely made the ice float, then the liquid
level should now have dropped by about 8% of the original
volume of the ice.

Tesha

[karlrschneider]

69. When ice melts, it ALWAYS occupies less volume as liquid water.

That is precisely why it floats (in water.) Obviously if you sat an ice cube on a glass completely full of mercury, it would melt and spill over the sides but we're talking about water here. And of course
salt water is somewhat denser than fresh water but the fact they are mutually soluble actually contributes to the phenomenon which is as you have mentioned is the reason about 90% of floating ice is
submerged. BTW, ethanol is considerably more dense than water - look at the mol weights: H2O is about 18, C2H5OH is around 49.

[Tesha]

80. But the liquid water doesn't always *DISPLACE* the same volume...

But the mass of ice doesn't always *DISPLACE* the same volume
of stuff the ice is floating in because the stuff isn't always
density = 1.000.

That's my point.

Mix in sugar (or sea salt) and the "stuff" has density > 1.00.
Mix in ethanol and the "stuff" has density < 1.00.

As I suggested in my previous post, the proof of this is that
in pure Scotch, your ice cubes probably sink. If they do, then
the liquid level in your glass *SURELY DROPS* as the ice melts
because the liquid water from the melted ice only occupies about
92% of the volume that the ice was originally taking. This is
still approximately true at the *BOUNDARY CASE* where the ice
cubes are just barely floating (in water-diluted so more-dense
Scotch). By just barely floating, I mean that the ice cubes
have no substantial volume above the surface of the liquid.

If you don't believe me, try it.

Tesha

[karlrschneider]

94. I'm not sure what 'pure scotch' is, but if you can make an ice cube sink

in a glass of it, I'll kiss your ass at noon on the steps of the First Baptist Church. But you have just contradicted yourself...first you say that adding ethanol makes stuff with density < 1.00 and in the very next paragraph you admit alcohol is heavier than water. :eyes:

There is probably some kind of liquid with a specific gravity exactly equal to that of pure H2O ICE but I can't think of what it would be...in that case (you called it the 'boundary case' which I've never heard of) the ice would be in equilibrium and would stay wherever it was put...at the top, bottom or middle.

At any rate, I think we are in agreement that ...let's put it this way: given an equal number of discrete molecules (same mass) of H20, they occupy a greater volume when frozen. Right?
Which is why ice floats, right?

edit: There are other 'types' of ice with very very different physical characteristics but they are not found anywhere in nature that I'm aware of. Asimov dealt with them in some detail in one of his books, I forget which one.

[bennywhale]

116. But isn't lots of the ice above the water locked in to the

glaziers/ice sheets, and also partly on the land of antarctica?

In that case ity would melt INTO the sea, thus giving it more water. is that not the case?

[karlrschneider]

125. Yes, that is the case which was presented poorly in the OP's article.

...

[Tesha]

139. I give up.

If you don't know what a "boundary case" is, we can't continue.

And it wasn't Asimov, it was Vonnegut in Cat's Cradle.

Tesha

[karlrschneider]

141. Okay, I dug through my books. "Counting the Eons", Isaac Asimov

1983, Doubleday & Co. Chapter 3, "Under Pressure"

Page 20.

I have no idea what Vonnegut may have said about it, I never read Cat's Cradle.

And since I'm obviously an idiot, why don't you help me out and tell me what a boundary case is?

[Tesha]

161. A "boundary case" is the situation where...

A "boundary case" is the situation where things change from
one regime to another. For example, if you're studying water
at thermal equilibrium at various temperatures AND STANDARD
PRESSURE, then there are three main situations and two boundary
cases:

o At temperatures below 32 degrees (F), you'll find ice

o At the boundary case of 32 degrees, you'll find some kind
of equilibrium between ice and liquid water

o Above 32 and below 212, you'll find liquid water

o At the boundary case of 212 degrees, you'll find some kind
of equilibrium between liquid water and water vapor

o Above 212, you'll find water vapor

For a single parameter (like temperature), each boundary
cases represent a single point on a continuous line. If
we're considering several parameters (like temperature
*AND* pressure), then the boundary case is a line within
the plane formed by the two parameters. And so on. For
example, here's the phase diagram for water when we
consider temperature *AND* pressure:

http://www.lsbu.ac.uk/water/phase.html



The boundary conditions are clearly visible as black lines.

Heading back to my hypothetical...

If you're sinking ice in alcohol, there's a boundary case
formed where you've added enough water that the alcohol+water
liquid is just barely dense enough to float the ice cubes.
I *BELIEVE* that typical Scotch (86 proof so 43% Ethanol)
is low enough density to allow ice cubes to sink, but if
I'm wrong, use a different source of alcohol; maybe ~150
proof Absynthe or 151 proof rum (although either may have
enough dissolved sugars to still keep the density too high,
in which you'll need some "White Lightnin'" or technical-
grade ethanol).

Tesha

[karlrschneider]

181. The term you were looking for is called the "triple point."

There are boundaries between the various phases but the specific term "boundary case" seems to be unknown to the world of chemistry which is why I questioned it.

Are you claiming that EtOH is LESS dense than water? What in the world ever gave you that absurd notion?

H2O mol. wt. = ~18
C2H5OH = ~48

????

[Tesha]

189. What gave me that absurd notion is...

> Are you claiming that EtOH is LESS dense than water? What in the world ever
> gave you that absurd notion?

What gave me that absurd notion is the article on "Ethyl Alcohol" in the Materials
Handbook. Fourteenth Edition where, on page 330 it states that the specific
gravity of EtOH is 0.79. But if you don't believe Brady, Clauser, and Vaccari, I
could find the same number for you in the CRC Handbook.

And, no, I WAS NOT speaking of the triple point. You might notice I mentioned
STANDARD PRESSURE. I even put in CAPITAL LETTERS so you wouldn't miss it.
And as the phase diagram that I included clearly shows, that the triple point
of water is at 6.1173 millibars, quite a bit below standard pressure.

Finally, I just conducted the beginning of the experiment I proposed. I plunked
ice chips into Jim Beam and Absenthe Suisse. Even though the ice had quite a
bit of air entrained into it (and so was less dense than solid ice), in the Jim Beam
it floated exactly at the surface (with no part of the ice above the surface). In
the Absenthe, it simply sank.

I think I'll leave the second part of the experiment (the melting of the sunken
ice) to you; you seem to need more convincing than I do.

Tesha

[karlrschneider]

193. Okay, I am properly chastised and highly embarrassed. I was WRONG.

Apparently my chemistry classes were far too long ago. Like 45 years. So you are correct, the SG of EtOH is less than that of water...but I can't seem to figure out -why-. I'm pretty sure I recalled the atomic weights of C, H, and O correctly (12, 1 and 16) so a mole of H2O and C2H5OH would be as I supposed, respectively 18 and 48 (grams/GMW)..? So where did I screw up? Obviously I overlooked something but I can't figure out what it is. I apologize to you and to anyone else who was misled by
my erroneous claim. Looks like I better stick to stuff I'm more sure of.

[Tesha]

194. No problem.

No problem.

You're absolutely correct about the molecular weights (where EtOH
far outweighs H20). But you're forgetting the fact that molecules take
up different amounts of space and specific gravity is established by
the overall density in space of the various atoms that make up the
molecules.

You can see the same effect (and even more so) if you look at gasoline.
Gasoline is a variety of alkanes from about C6 up to about C10, but
let's take octane C8H18 as the examplar. It has a molecular weight
of about 114, but its density is usually taken as about 0.703, so again,
quite a bit lighter than water. (Gasoline as a whole is about 0.75.)

Tesha

[karlrschneider]

196. How many ways can I spell "duh". As a pilot and engineer I surely

know and have known full well that gasoline and most hydrocarbons are less dense than water. It's why I drain the water from the bottom of the tanks on our plane when I pre-flight it. It somehow completely escaped my not so well remembered notice that long-chain molecules obviously do take up more 'space', as it were. I think my 'reasoning' (not an excuse) must have had something to do with the fact that (most/all?) alcohols are mutually soluble with water and I neglected to grasp that important distinction.

[longship]

151. Here it is in simple scientific language.

Ice is less dense than liquid water. This is why it floats.

When something floats on a liquid, it sinks to a level where it displaces exactly the same mass of water as the floating stuff. Since ice is less dense than water that means that some of the ice will be above the surface of the water.

I recommend all the doubters here take up Tesha's challenge and drop ice cubes into Scotch (recommend single malt variety) until they are convinced that science still works. Oh, and one more thing... Leave out the sugar. ;-)

And Tesha is correct. Displacement is by mass, not by volume.

[longship]

18. Correct, except for...

The fact that if you read the OP again, it's apparent that the worry is not just Ross breaking up, but the West Antarctic shelf, which is land-based, subsequently sliding into the ocean. The Ross is a buttress to the West Antarctic. If Ross goes, the land-based shelf can slide more quickly into the ocean.

[karlrschneider]

23. The way it is written:

"SCIENTISTS working in Antarctica fear the Ross Ice Shelf, an ice platform the size of France, could collapse quickly and trigger a rapid rise in sea levels."

Implies that the Ross itself would trigger the rise. I suppose the sloppiness is from the writer instead of the scientists.

[longship]

26. Science journalist poor choice of words.

I'm sure that the scientists did not put it that way. The difference is that the loss of the Ross would trigger a rapid rise in sea levels due to the fact that the West Antarctic shelf would then slip into the ocean must faster.

[karlrschneider]

44. Exactly. Maybe I'm too picky but I want scientific facts to be accurately

represented. :-)

[siligut]

78. Picky?

Repugs never counter repugs, facts smacts, who cares, we are on TV! Or whatever medium being fed to the public. George Stephanopoulos said it “The republicans are organized”, he was quickly hushed. Don’t want the demos to catch on; right?

[lumberjack_jeff]

68. "trigger" is okay. They didn't say "cause" or "result in".

A loss of land-supported ice in antarctica or greenland would result in major ocean rise. Loss of the ross ice shelf or the north polar ice cap could trigger that.

[HiFructosePronSyrup]

74. The collapse of the shelf would trigger a rise.

Seems to me, the problem is a sloppiness in comprehension.

[Czolgosz]

103. Are you seriously thinking that the Ross Ice Shelf (the size of France)

would not displace a large volume of water if it detaches from Antarctica and falls into the Ross Sea?

If so, you do not understand the nature of an ice shelf.

Also, you are mistaken in suggesting that the melting of the Ross Ice Shelf will not raise the seal level by itself. You are failing to adequately account for the differences in the density between sea water and fresh water. Dr. Peter Noerdlinger discusses this phenomenon in an excellent paper entitled "The Melting of Floating Ice will Raise the Ocean Level."

[karlrschneider]

109. I'm aware of the differences in density between fresh and salt water

and of Noerdlinger's grasp of the obvious.
http://nsidc.org/news/press/20050801_floatingice.html

He correctly says that the increase of melt volume is around 2.5 percent because of this difference
but that figure is applied only to that volume of ice that melts, NOT to the entire ocean. He also
correctly notes that the SHELF is already IN the water.

edit: here's some arithmetic:

The Ross shelf is about 30 x 10^6 KM^3

The surface of the earth's oceans is about 360 x 10^6 KM ^2

2.5% of the shelf is ~75,000 KM^3

So 75 x 10^3 / 360 x 10^6 = .0002+ KM, or ~8 inches.

[Czolgosz]

113. I'll accept that as an admission that you have been hectoring people

based on an incorrect understanding of the underlying science.

[karlrschneider]

121. Feel free to accept anything you want. My complaint wasn't with science

which I understand very well, it was with the way it was presented in the article which was rife with errors and some comments which were also. You have -appeared- to imply that the Ross shelf is somehow
suspended by a cantilever that keeps it from physically behaving essentially like any floating ice.
My contention is that there is water underneath it just as there is below any iceberg and that the
buoyancy forces (and its weight) are enormous compared with what little tensile strength it would have by virtue of whatever 'attachment' it shares with the land.

[Czolgosz]

128. That rise in sea level nearly equals the rise in the sea level for the whole past century

and that is just from the melting of the ice shelf and not counting the more significant effect of water displacement or the even more significant effect which will result from the more rapid melting of glaciers that feed the Ross Ice Shelf (and they ate 100% land-based glaciers so every bit of melt adds to the sea level).

You use very conservative numbers to calculate an 8 inch rise in the sea level from ONE ASPECT (the melting of the ice shelf) of ONE EVENT (the Ross Ice Shelf's decline) and it equals about 75% of the sea level rise for all events over the past century and you dismiss that as trivial?

Plus, how many times have you criticized people who posted in this thread for suggesting that the melting of the Ross Ice Shelf would raise the sea level? What do you say to them now that your own conservative calculation confirms that this factor alone (a minor factor when compared to the water displacement and the consequent increased vulnerability of the Antarctic glaciers) would by itself raise the sea level more than the past half century of worldwide events?

[karlrschneider]

133. Please don't put words in my mouth. I never "dismissed" it as "trivial"

I simply pointed out that the ~8 inches is a hell of a lot different from the figures that would be inferred by the 16 to 25 FEET figures suggested in the OP's referenced piece. I explicitly stated in other posts that the loss of the ice on land in Antarctica and Greenland is a completely different
scenario.

[mcg]

199. Good point, but the article says around 1.57 inches

from the melting of all sea ice and floating ice shelves.

[ashling]

54. I could be wrong, but isn't

this geographical feature supported at least partially by land. I don't think it is the same as a floating iceberg or ice cube.

[mcg]

59. I think that is why they are saying the melting will rise sea levels. nt

[JHB]

31. The SHELF is floating on water, but it's holding back glaciers ON LAND...

...and if the shelf goes, those glaciers are going to flow into the water (faster than they do now) to replace it. Net result: water level rise.

That's this part here:
"If the ice shelf goes, then what about the West Antarctic Ice Sheet? What we've learnt from the Antarctic Peninsula is when once buttressing ice sheets go, the glaciers feeding them move faster and that's the thing that isn't so cheery."

[JHB]

46. An additional factor is that the ice in Antarctica is so thick and heavy...

...it's actually pushing the land beneath it down. So if the sea-floating ice shelf collapses or breaks up, not only will the on-land glaciers move faster to replace that sea-ice, but that will reduce the pressure on the land, letting it rise back up, which is going to keep those glaciers flowing longer.

[Warren DeMontague]

34. Then how come every global warming scientist predicts rising sea levels?

Where's that water coming from?

[benEzra]

50. Ice that's currently sitting ON LAND...

but would flow into the ocean and raise sea levels if enough warming occurred.

You can also get a few feet of rise from thermal expansion of the existing ocean water, IIRC.

[kentuck]

55. Because the ice will melt if if floats to warmer waters??

Seems to make sense to me. And if a block of ice breaks off from a solid mass and then sinks deeper into the water, the level would also rise, I would think?

[kestrel91316]

62. Believe it or not, the scientists CAN think rationally. True, the

ice sheets over the ocean can melt and the sea level will not change. The important thing is that those same ice sheets hold back the ice on land from sliding into the sea, and that land ice is being nicely lubricated by meltwater between the ice and the land surface. Once the land ice slips into the ocean, the levels OF COURSE rise.

You should watch An Inconvenient Truth. It explains this rather horrifying situation quite nicely.

If we lose Greenland AND the West Antarctic ice, oceans will rise 20 feet. Then there's all the REST of the ice that sits on the Antarctic land mass which is miles deep and with enough warming, it slides off into the oceans, too. We're talking 100 ft rise in the oceans with THAT, I bet. And yes, this process is accelerating. The Larsen ice shelf broke apart in 30 days. It just vanished.

[Uncle Joe]

70. It can trigger an effect though causing the land ice to melt faster which

in turn will raise the sea levels.

[alcibiades_mystery]

76. Actually, there's land-based ice and floating ice

When the floating ice goes - you're correct. It does not raise sea-levels. The problem is that the floating ice prevents melting of the land-based ice. When the floating ice goes, the land-based ice starts in, and that's when sea levels rise.

Not all the ice is floating. A significant portion of it is land-based and WILL raise sea levels significantly.

[Ganja Ninja]

84. I don't believe it's all floating.

I could be wrong but I think some of it is supported by land. Some of it is suspended over the water and some may be resting on the sea bottom so that when it collapses it will all become floating ice and the displacement will cause the sea levels to rise overnight.

[karlrschneider]

98. Please enlighten me how ice can rest on the sea bottom?

Is it frozen deuterium oxide?

[rman]

102. A lot of ice and not to deep water will do it,

just so that there's to much ice for it to float given the depth of the water.

[karlrschneider]

107. I can see how that might be 'intuitive' but it's wrong.

A block of ice the size of Texas will float in one inch of water. Trust me on this. :-)
edit: I mean there would be an inch of water -beneath- it...obviously there would be more water
going up to about 85% of the way to the top of it, all around...

[Czolgosz]

110. You are mistaken in thinking an ice shelf is an iceberg. It is not. An Ice

shelf attaches to the land at the coastline.

An ice shelf is only somewhat supported by its buoyancy; it is also supported in large measure by its connection to the land. You should know this because if an ice shelf truly "floated" it would rise and fall with the tides. An ice shelf does not rise and fall with the tides because it is fixed to the land (and it it wasn't, no one would be terribly concerned that the ice shelf was detaching).

To the extent that an ice shelf does not float, its detachment and falling off into the surrounding ocean will displace water.

Because the ice shelf is then turned into an iceberg, it will melt faster due to the greater exposure of surface area to the surrounding water, due to the greater interaction with the convection of the water, and due to drifting into warmer areas.

Ice blocks melting in fresh water do not raise the level of the body of fresh water. This is not true for salt water because melting ice in salt water DOES raise the level of the water (the difference is marginal in a cocktail glass with an ice cube, but with an iceberg the size of France, that margin makes a huge difference).

Float an ice cube in salt water if you don't understand this (it floats much higher if the water is salty enough). As the ice cube melts, the water level DOES rise. Repeat the experiment with fresh water, and the result you predict is accurate. The difference is in the density of the salt water.

[Ganja Ninja]

160. Lets try an experiment.

Go out and buy a block of ice. Take it home and fill the bottom of your bathtub with 1" of water then drop it in. Let me know the results when you finish.

[karlrschneider]

184. You don't understand the experiment. The proper way to do it is this:

Put the block of ice in the tub then add water until the bottom of the ice is one inch above the bottom of the tub. Voila, it is now floating in one inch of water.

[longship]

179. You are correct.

But consider this. This is a huge ice shelf. The proportion of the shelf sitting on terra firma is probably small compared to the float ice. I guess one should say that the collapse of the Ross ice shelf will not *substantively* change water levels.

Others claim that the difference of liquid sea water and fresh water ice is substantive, but they are wrong. Archimedes applies regardless.

[bennywhale]

114. Ok, you're right and 90% of the world's scientists are wrong. Lets

just sit in our bloated pampered lives and drown, starve, burn, and dehydrate the rest of the world to death. Cos it won't be americans who will suffer most it will be the poor, in Asia and Africa. We'll just keep on pumping out 25% of the world's pollution with 5% of its population and be judged by history.

Our gluttonous lifestyles are worth it.

[Katzenjammer]

118. I believe you might be thinking of the Arctic. Antarctica is a continent

The ice in the Arctic is floating, the ice on Antarctica isn't.

[Bjorn Against]

155. Much of it is land based ice...

Al Gore illustrates this nicely in an Inconvenient Truth. If an ice cube is merely floating in a glass of water it will not raise the level, but if the cubes are stacked a bit higher so that the ice actually sits above the level of the liquid then of course the ice WILL raise the level of the water. This is land based ice, and it is a cause for serious concern.

[grizmaster]

11. yup

[Blackhatjack]

2. I wonder how many people understand the gravity of this happening?

I think it just goes right over their heads, until it actually happens.

A common characteristic of inattentive comfortable societies.

[bennywhale]

3. I can't belive that this isn't

THE issue of the 21st Century.

It is in other parts of the world, like parts of Europe. Or at least the rhetoric is any way. Global warming should be commanding all political and media energy.

It isn't because it is a complex problem, hard to define in black and white terms and its gonna take some sacrifices to solve.

no-one wants to hear that.

Sigh indeed

Run for the hills brfore they burn

[EFerrari]

4. If the sea level goes up 5 m, I will be sitting on sea front property.

:scared:

[ToolTex]

10. With a bunch of squatters sharing your living room.

:hide:

[EFerrari]

83. LOL! Yes, and their furniture and their cars!

:hi:

[Lone_Star_Dem]

6. I knew there was a reason I live on a hill

How sad it is that we've nearly reached this point. Yet it's even sadder that so few care about what's taking place.

[karlrschneider]

8. These people are fools. The Ross shelf is just floating ice.

If it 'breaks away' it will not affect sea levels.

[IdaBriggs]

13. Wow. Scientists are officially "fools" -- are you on the right board?

I would ask you to explain what gives you your brilliant insight, but common sense says WATER SPREADS OUT WHILE ICE DOESN'T which makes me want to call you all sorts of insulting names.

Either way, thanks for helping to keep this thread kicked.

:eyes:

[karlrschneider]

19. Okay Madame Scientist...try this:

Fill up a glass nearly full with ice and add enough water to come right up to the brim. Let it sit and melt. When the water runs over the edge call me and I'll buy you a new car of your choice.

[mcg]

24. but the ice is already over the brim, that's the problem.

[karlrschneider]

27. Jesusfuckingchrist I give up.

This is something anybody can do in their own kitchen in half an hour. Get back to me after you've
disproven the laws of physics, okay sweetie?

[HiFructosePronSyrup]

42. Try this.

Unplug your freezer and leave the door open. The level of water on your kitchen floor will rise.

Quit being obtuse.

[karlrschneider]

49. My kitchen floor has a drain.

:eyes:

[HiFructosePronSyrup]

52. There's a hole at the bottom of the sea.

But it's not a drain.

[dad]

67. Really?

That's cool. I never heard of that. What is your floor made out of?

[karlrschneider]

72. Some sort of tile. I can wash it down with a hose, very convenient.

:D

[eppur_se_muova]

90. Do dishes and floor at the same time! Now that's convenience! nt

[hootinholler]

163. My ex would not let me do that when we remodeled

I was sad.

-Hoot

[truebrit71]

86. Fan-Fucking-Tastic come back!! You owe me One New Monitor....

...that has hysterical!!!!


:rofl::rofl::rofl::rofl::rofl::rofl::rofl::rofl::rofl::rofl:

[Czolgosz]

104. Give up? You haven't even tried to think it through. Salt water is much

denser than fresh water.

Here is a fresh water ice cube floating in salt water:



Here is the water level in the glass when it the fresh water ice cube melts:



Which picture is confusing you so?

[TX-RAT]

136. Really laughing at this one.

I don't think you can get any clearer or simpler in you explanation. Does your head heart yet?

[longship]

29. The physics is simple, my friend.

There's ice above the surface because ice has a lower density than liquid water. It's floating!!

By Archimedes principle the ice displaces precisely the volume of water represented by its mass, which is precisely the mass of the equivalent volume of liquid water. So, when the ice melts, the level does not change.

[Czolgosz]

105. The Archimedes principle only applies to fresh water. Ice floating on

a denser liquid will raise the liquid level when the ice melts. Salt water is denser than fresh water.

[longship]

150. WHAT!!!!???? That's utter bollocks.

What physics class were you in? The Archimedes principle applies to ***any*** liquid, whether it's water, gin, petroleum, or even lava.

It's a very simple thing. When something floats on liquid, it sinks to a depth such that it's mass displaces an equal mass of the liquid. It doesn't matter what liquid it is.

The science illiteracy in this forum is astounding.

[IdaBriggs]

51. Why don't you try this? Put an ice cub on your counter.

When it melts, see if it stays in the same contained area, or spreads all over the place!

Call me when it continues to stay in a cube that is two inches high, and we'll get the National Enquirer over to your place INSTANTLY!

[symbolman]

57. Try this

Fill a glass of water to the brim, THEN ADD three ice cubes, and I'll take a Mercedes..

They are talking about ICE on LAND sliding INTO the ocean, where it's never been..

I like green...actually, I'd rather have a BOAT :)

[karlrschneider]

71. You have changed the experiment. No Mercedes for you!

:evilgrin:

[Javaman]

95. Why didn't you respond to post #51? nt

[karlrschneider]

100. Oh, maybe because it was a stupid question?

:eyes:

[Javaman]

162. You know what is amazing about your responses?

Although you know what you are talking about your level of arrogance is just amazing.

I guess you missed the lesson on how to blend intelligence with class.

Now please grace me with one of your witty patented retorts.

Have a wonderful day. :)

[karlrschneider]

185. I'm sorry you fail to distinguish between arrogance and exasperation.

How was that?
;-)

[Javaman]

198. And once again you failed to beable to melt class and intelligence. nt

[leftchick]

61. I believe they are referring to the glaciers that will certainly follow

The Ice Shelf break.....



That is a LOT of water into the "glass".

[lectrobyte]

14. Lighten up Francis. Look up the meanings of buttress and shelf, and

get back to us. HTH! HAND!

[Jacobin]

15. Its hard to get good information, because of the

politicization of science on both sides. Gore's movie is a good start

[Iwasthere]

16. Fill glass with water and ice cubes all the way to the bottom

Now let it melt and watch the water flow over the rim of the glass. Then tell me it's just floating ice! Geeeshh!!!

[karlrschneider]

25. Did you forget the sarcasm thingy?

:eyes:

[Lone_Star_Dem]

37. I do understand how their theory is wrong

They will still be taking up the same amount of space in the end.

Yet I have a question. If I were to float a scoop of ice cream on top of a full to the rim glass of soda, when the ice cream melts it will run over. Is that not similar to what we have here?

Honest question, no barbs intended.

[karlrschneider]

48. Here's a suggestion. Try it.

(It won't run over)

[Lone_Star_Dem]

53. I understand now

I knew that what you said was true, but was having a hard time explaining to myself exactly why. I got my refresher course a couple of post down.

Sorry to bug you, I'm just a curious person. :)

[senaca]

79. would the ice shelf have the same pollution factor that occurs in water along our shores?

I guess what I'm asking is, would oil spills, acidity, etc. cause a differentiation of how much or little the water could rise. Would there be a dilution factor that negates the difference in composition in polluted water?

[mcg]

21. It is the size of France and goes as high as 50 meters above sea level.

Multiple the average height of it above sea level by the size of France. All that water will be added to the seas if it melts, and it looks like it will melt, followed by other shelves.

[karlrschneider]

28. The water (in the Ross) is ALREADY in the sea!

groan...

[longship]

32. Wrong-O.

The top of the shelf is above sea level because ice has lower density than liquid water so it *floats*. However, the mass displaced by the ice is exactly the same mass as the liquid water if the ice melts. Google "Archimedes principle".

[Lone_Star_Dem]

47. Thanks!

"A body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid."

I knew there was something I once knew but had forgotten that would make this make sense to me. I greatly appreciate the reminder.

[mcg]

58. That is assuming it is all floating.

Is that true? If not, how much of the Ross Ice Shelf is not floating on water?

[longship]

147. Okay, presuming that it isn't floating...

The ice shelf is pack ice floating on the ocean. There's no mechanism by which the ocean is going to freeze all the way to the continental shelf. If the Ross melts, it will not contribute to water levels. That's the way it is. Sorry.

[longship]

22. Read the article again.

They are not saying that the Ross melting will increase levels. They are saying that the Ross is a buttress for the West Antarctic sheld. If Ross goes, then so might the West Antarctic, which is land-based and *would* increase water levels.

[Bandit]

60. Of course they are, they are talking about three million year old ice

Don't they realize the world was "intelligently designed" only six thousand years ago..:crazy:

[karlrschneider]

75. Heh, well of course. I forgot about that!

;-)

[TX-RAT]

140. I have a better idea

Take 2 glass's, put in 4 ice cubes each, then put in 3 ounce's of Crown Royal. You take one and i'll take one and we can just sit back and watch this thread. My moneys on the fluid level of those glass's going down.

[leftchick]

81. "release rivers of ice that would cause sea levels worldwide to rise"

It is not a hard concept to understand...

http://www.space.com/scienceastronomy/planetearth/ice_melt_010117.html

Meltdown: Satellites Show Accelerated Polar Ice Threat
By Robert Roy Britt
Senior Science Writer
posted: 07:01 am ET
17 January 2001



Vast sheets of ice on the warming fringes of Antarctica may be on the verge of collapse and could eventually release rivers of ice that would cause sea levels worldwide to rise more rapidly than expected, according to new study of satellite images released Tuesday.

Scientists have long known that polar ice has been melting for the past 14,000 years or so, and that seas are on the rise. So far, the major contributor to rising seas is what's called thermal expansion: As oceans warm up, (as current data confirms), the water expands and sea levels actually rise.

The Environmental Protection Agency has estimated that sea levels have been rising nearly a foot (0.3 meter) per century and will rise at least that much, possibly more, over the next 100 years. The EPA and the United Nations have both said that in a worst-case scenario -- depending on how much global air temperatures increase -- seas could jump 3 feet (1 meter) by 2100.

And each vertical inch can translate into several horizontal feet of flat lowlands.

Many scientists expect that global warming will likely continue to warm the oceans for decades or centuries to come. And increasingly, experts warn that small islands, farmland and coastal cities occupied by hundreds of millions of people could be swamped. (Others dispute the extent and causes of global warming).

[senaca]

85. Thanks for the article as it helps to understand the sit. better. n/t

[LSK]

120. fill a glass full with ice, then fill it tothe brim with water, then add more ice

Will the cup flowith over??????

[mcg]

12. Ross Ice Shelf

http://en.wikipedia.org/wiki/Ross_Ice_Shelf



http://earth.rice.edu/mtpe/cryo/cryosphere/cryosphere_why.html

"So in the presence of ice generally more than half the solar radiation falling on it is reflected back to space. This represents a loss of energy from the Earth system and can result in colder conditions. These colder conditions can lead to increased ice cover, and thus, a further reduction in the energy absorbed in the Earth system. This is called a positive feedback."

[leftchick]

115. I Wish More People on this Thread Would READ it!

sheesh! Wasting all this time arguing a stupid non-issue.

And You are most welcome.

:)

[mom cat]

33. Bush knows all this. Why do you think that he is buying land in Paraguay!

[BeHereNow]

146. Mom Cat hits nail squarely with truth hammer...

We are so fucked.
"An Inconvenient Truth" tells us all we need to know
about the future in our lifetimes.
God help the kids who are not family members
of the global elite.
The twins party ing in South America?
Gee, wonder why.
All hell is about to break loose.

BHN

[G_j]

56. Supreme Court divided over landmark global warming case.

Supreme Court Takes On Global Warming
By Elizabeth Millard
November 30, 2006 9:09AM


The Supreme Court's ruling in the global warming case involving Massachusetts and the Environmental Protection Agency is expected in July, and could set off a chain of similar lawsuits by states and environmental activist groups. In particular, the Supreme Court ruling will determine whether California will be able to proceed with a law that restricts tailpipe emissions of greenhouse gases. ..more..

http://www.sci-tech-today.com/story.xhtml?story_id=132007EFPI4O
--
Supreme Court divided over landmark global warming case.

“The nine-member US Supreme Court appeared split as it took up the debate over global warming, with rival lawyers arguing whether some greenhouse gas emissions should be regulated.” The AP reports that the Court’s “conservative members seemed to recoil at the idea of government regulation, while their liberal colleagues openly embraced it.” The “pivotal swing vote,” Justice Anthony Kennedy, “did not reveal where he stood.”

UPDATE: More analysis of Kennedy’s role in the case at SCOTUSBlog.

http://news.google.com/nwshp?ie=UTF-8&oe=UTF-8&hl=en&tab=wn&q=%22Supreme%20court%22%20warming

[bullwinkle428]

63. "No one could have anticipated the collapse of the Ross Ice Shelf"

I only wish I could be joking about this, but I fear for the worst if and when this happens...

[lovuian]

77. Inconvenient Truth has a map that shows all the

land that will be overrun by water
and unfortunately lots of millions of people live on them

this is Mother natures revenge

and yes I think Bush knows damn well what is going on

whats got everybody in at freakout is that Tony Blairs England could be under water...

Thats a shame

[bullwinkle428]

87. I saw an ABC special which highlighted parts from "An Inconvenient

Truth" a couple of months back and I do recall that specific piece of information being mentioned. It was quite chilling to see the potential results. I'll definitely have to rent the DVD now that it's been released.

[pitohui]

117. when is all this supposed to happen?

i haven't been able to see "an inconvenient truth" down here, hopefully i will soon

[bullwinkle428]

148. Do you live outside the U.S.? The DVD was released just over a week ago

here in the U.S....

[pitohui]

164. i live in southeast louisiana

last time i was at the video store it wasn't there, maybe next week

[ananda]

64. The SIZE of FRANCE!

Whooaa.. pretty freaky!

[jwirr]

65. While I do not know much about how physics effects this idea, I

think the a large piece of ice droping suddenly into the ocean could cause huge waves against nearby lands and maybe further.

[Uncle Joe]

73. I agree, there could also be a tsunami danger from this. n/t

[tjwash]

88. Oh it's just a theory, like evolution and aeronautics.

Anyone with any sense gets their science from the bible. :eyes:
/snarky religious guy

In all seriousness though; a few years ago I did a lot of IT consulting work with people at the SIO in San Diego. Back before anyone ever even heard of it, they were showing me satellite pictures from the north pole that they were researching, that showed how the ice was retreating very steadily from the north pole. The one that stunned me was a photo of a connecticut sized chunk of glacier that just broke off from the north pole.

Luckily for us, most of the north pole already "floats" and displaces it's mass. Not true of the south pole.

When the rising earth temp melts enough of the water locked in that ice in the north and south pole, a rising sea level is going to be the least of our problems. The drastic drop in salinity that is going occur is going to wreak havoc with the current convection currents and cause a drastic switch. The result will be a shift in the climate zones that will be absolutely brutal. Wet areas will dry up, the agriculture centers will get no rain for years, and the driest climates will get massive rainfall and immense flooding.

It's more serious than a rising sea level by far...

[lovuian]

129. I agree the salinity of the ocean has started Atlantic current

has slowed and it really easn't surprising that the Gulf did not see many Hurricanes cause the Gulf waters were cooler due to the slowed current

Its happening already

[ecstatic]

96. What if their activities in the area speed up the collapse? nt

[leftofthedial]

106. here in Colorado, we soon will have the beach AND the mountains

Woo Hoo! Great news. I'm gonna borrow as much as I can and start buying up soon-to-be-primo real estate!



Seriously, this is scary as shit.

[pitohui]

119. what does "quickly" mean?

there is no meat to this article, what's "quickly"

in geologic terms it could be 10,000 years!

seriously, we need to know, an event of this nature taking place in the next 5 years requires a different response than if it is going to occur in 500 years

i assume it WILL occur, i see no political will to put a halt to the causes of global warming

[Bucky]

142. The Ross Ice Shelf melting & destroying millions of acres of beachfront is no proof of GlobalWarming

Just practicing... in case I ever have to "pass"

[ConservativeDemocrat]

154. LETS HOPE THIS HAPPENS SOON

Really. I want Florida to flood.

It's the only way people will take global warming seriously. Until then, we're going to be stuck in this "Tragedy of the Commons" problem with CO2, where we each individually make choices that collectively doom the planet to the way it was in the late Triassic, where Siberia was a searing desert, the world's oceans turned acid, and 90% of the species on the planet died.

We can pull it back from that, but only if the world gets a real shock, sooner rather than later.

- C.D. Proud Member of the Reality Based Community

[pitohui]

166. what a stupid and irresponsible remark

once it has happened, it has already happened, duh

there is no way this can happen and just punish florida for the amusement of cold-hearted yankees, if it happens, the entire world is destroyed, all of the great cities of the world and all of the riches of the world and 70 percent of the world's population are on flood plains

crikey, we can't "pull back" from that, catch a clue train

if you don't really believe it will happen, no use wishing ill on florida, if you do believe it will happen, you need a better and more thoughtful response than "ha, shows them"

[ConservativeDemocrat]

173. Flooding is bad, but nothing compared to what could happen

Unless we address this, we could set off a global warming chain reaction that could make half the landmass of this planet effectively uninhabitable. Unfortunately, the vast majority of people in the world are simply not willing to make the lifestyle changes required to reverse this.

Not unless they get a little ecological shock and awe.

Again, I wish that human nature wasn't what it is. But until people get their hands burned badly by global warming (and flooding is the least painful of these alternatives), I doubt they'll agree to do much of anything to stop it.

- C.D. Proud Member of the Reality Based Community

[Bridget Burke]

178. Florida isn't the only place that would flood...

Isn't your avatar one of those groovy northwestern states? Don't they have coastlines?

[ConservativeDemocrat]

183. I am perfectly well aware that there'd be flooding worldwide

...in fact, that's the whole point. Until we see a worldwide consequence, there will be no real worldwide attempt to fix this.

- C.D. Proud Member of the Reality Based Community

[LSK]

168. if FL floods, NYC floods

And that includes Wall Street. You know, that little place that has a huge impact on the world economy???

[pitohui]

171. thanks, lsk

sure would be nice if people looked at a map once in awhile, wouldn't it?

i'm still trying to figure out how he thought florida would flood just all by itself on its lonesome, sigh

[mcg]

156. I think I'm switching sides on this debate,

after reading this wording:

"... ice shelves, floating extensions of the grounded ice sheet."

"As it is already floating the disintegration of Larsen will have no impact on sea level. Sea level will rise only if the ice held back by the ice shelf flows more quickly onto the sea."

from this web page:
http://www.antarctica.ac.uk/News_and_Information/Press_Releases/2002/20020319.html

So an ice shelf is indeed floating.

In the article shown in the first post it says

"... Ross Ice Shelf ... could collapse quickly and trigger (not cause by itself) a rapid rise in sea levels.
-snip-
... the West Antarctic Ice Sheet holding an estimated 30 million cu km.
... its (the sheet's) collapse would make sea levels rise by at least 5m ..."

[mcg]

200. However, see post 109 "...differences in density between fresh and salt water"

It looks like the melting of the Ross Shelf would cause by itself a slight rise in sea levels due to salt water being denser.

[Poiuyt]

157. I have a relative who is a researcher in the Antarctic - Here's what he said:

He's a professor at a major US university doing ecological research at Palmer Station in the Antarctic. In fact, he is on a boat right now on his way back from the Antarctic to the US. I emailed him about this subject and this is what he wrote back:

"The Ross Ice Shelf is a floating ice shelf so its melting won't affect sea
level directly. But its presence anchors the big continental ice sheet
behind it. So if the Ross goes, that could hasten the collapse of the West
Antarctic sheet -- my understanding is that it is unlikely in the next
century, but you never know..."

Hope this helps

[karlrschneider]

159. Good. Thanks.

...

[pitohui]

167. thanks, this is what i wanted to know

"The Ross Ice Shelf is a floating ice shelf so its melting won't affect sea
level directly. But its presence anchors the big continental ice sheet
behind it. So if the Ross goes, that could hasten the collapse of the West
Antarctic sheet -- my understanding is that it is unlikely in the next
century, but you never know..."

this has been my understanding also, the article cited above was very poorly written in my view

"could" and "might" in the next century are quite different from "will" in the next couple decades, "could" and "might" gives us a chance to take action, "will very soon" means all we can do is fend for ourselves and live for today because it's too late

it is very important to be clear about the odds

[Blue_Tires]

158. ttt!

[Name removed]

165. Deleted message

Message removed by moderator. Click here to review the message board rules.

[bridgit]

169. welcome to du, infothe...

:hi:

[begin_within]

170. After reading this thread, I need one of these...

[mainegreen]

174. That's not scotch!

:P

[begin_within]

175. Eeew - I don't like scotch. It's like drinking Listerine or something.

[KansDem]

176. Yeah, well all this talk of alcohol and ice has made me "thirsty"

...and it's still five hours to 5pm! ;(

[Bridget Burke]

180. For a "chilling" review of possible environmental tipping points....

Read this piece from Mother Jones. Yes, the tipping points are mostly connected.
www.motherjones.com/news/feature/2006/11/13th_tipping_point.html

The author does hold out hope....

[HiFructosePronSyrup]

191. There are two fundamental misunderstandings in this thread.

One scientific misunderstanding is that if you have pure ice cubes in a glass of pure water, that the melting cubes will change the level of the water. That is a scientific misunderstanding.

The second misunderstanding is that the Ross Ice Shelf is analogous to ice cubes in a glass of water, and if it melts it will not affect the sea level. This is the other scientific misunderstanding. Of this two misunderstandings, the latter is the less forgiveable.