Sea Level new analysis and graphing tools

a reply to: pteridine

If the entire ice sheet melts, the water level around Greenland will drop tens of meters.

I understand the gravitational effect, but would it really be tens of meters?

originally posted by: Phage
a reply to: pteridine


That is correct. Not sure if the effect would override the overall rise in sea level though.

It is where it is now because of the mass [MASCON?] of the ice. The oceans are not flat and the distribution would raise water significantly in some areas. When the meltwater disrupts the Gulf stream and freezes northern Europe, that glacial formation will collect water and gravitationally attract seawater, inundating frozen Holland and Denmark.

a reply to: pteridine

It is where it is now because of the mass [MASCON?] of the ice.

Partially.

originally posted by: D8Tee
a reply to: pteridine

If the entire ice sheet melts, the water level around Greenland will drop tens of meters.

I understand the gravitational effect, but would it really be tens of meters?

I'll look for my reference.

originally posted by: pteridine

originally posted by: D8Tee
a reply to: pteridine

If the entire ice sheet melts, the water level around Greenland will drop tens of meters.

I understand the gravitational effect, but would it really be tens of meters?

I'll look for my reference.

www.sciencemag.org...

WASHINGTON, D.C.—The Greenland ice sheet is melting. If you live in nearby Norway, how worried should you be about that sudden influx of water flooding your house? It turns out, not nearly as worried as you should be if you live in Chile. People tend to imagine that when an ice sheet melts, it adds water to all of the world’s ocean uniformly, like a bathtub filling up. “That isn’t even close,” Harvard University geophysicist Jerry Mitrovica told attendees yesterday at the annual meeting of AAAS (which publishes Science) in Washington, D.C. “Each ice sheet has its own pattern of sea level rise.” Mitrovica mapped what would happen to the world’s ocean if the rapidly melting Greenland ice sheet collapsed (as seen above). Right now, that ice is a huge weight pushing down Earth’s crust in and around Greenland. So when it’s gone, that land will pop up. An intact ice sheet also has a noticeable gravitational pull, which attracts water to the region. No ice means that water will rush away. Both of those effects actually add up to lower sea levels in the area right around the former ice sheet, Mitrovica said. When Greenland melts, places as far away as Norway and Scotland could actually see the sea level fall by as much as 50 meters. “But you pay the price somewhere,” Mitrovica said. In the Southern Hemisphere, you get more [sea level rise] than you bargained for.” The same counterbalancing effect holds for the West Antarctic Ice Sheet. If it were to collapse, the seas would rise the highest near Washington, D.C., and Northern California.

a reply to: pteridine

So when it’s gone, that land will pop up.

a reply to: pteridine

When Greenland melts, places as far away as Norway and Scotland could actually see the sea level fall by as much as 50 meters.

I find that rather... shall we say, incredible? Is there any peer reviewed sources?

originally posted by: Phage
a reply to: pteridine

It is where it is now because of the mass [MASCON?] of the ice.

Partially.

www.geological-digressions.com... discusses the rapid rebound of land after ice sheets melt.

"An example from the last glaciation nicely illustrates these points. During the last glaciation (beginning 110,000 years ago) most of Canada and parts of northern USA were covered by the Laurentide Ice Sheet.

The ice-sheet began to melt about 19000 years ago and finally left the Hudson Bay region about 8000 to 9000 years ago. The land mass in the Hudson Bay area began to rise, initially at an incredible 9-10m per 100 years, slowing to the present rate of about 1m per 100 years."

a reply to: pteridine
So...
How much does gravitation have to do with the proposed relative sea level in Greenland as opposed to isostatic rebound?

www.abovetopsecret.com...

a reply to: pteridine

I understand 'the land popping up'. I have taken geology courses. It's the gravitational effect, i didn't think it would allow for a 50 meter sea level difference.

An intact ice sheet also has a noticeable gravitational pull, which attracts water to the region. No ice means that water will rush away. Both of those effects actually add up to lower sea levels in the area right around the former ice sheet, Mitrovica said. When Greenland melts, places as far away as Norway and Scotland could actually see the sea level fall by as much as 50 meters.

originally posted by: D8Tee
a reply to: pteridine

When Greenland melts, places as far away as Norway and Scotland could actually see the sea level fall by as much as 50 meters.

I find that rather... shall we say, incredible? Is there any peer reviewed sources?

It's possible that somewhere between Mitrovica's presentation and the Science Mag units got confused and cm became meters. I am not a geophysicist and only read about this a year ago.
I'd say search on Mitrovica. Harvard should list his publications.

originally posted by: Phage
a reply to: pteridine
So...
How much does gravitation have to do with the proposed relative sea level in Greenland as opposed to isostatic rebound?

www.abovetopsecret.com...

I don't know the relative amounts in this model.

The CO2/global climate change is more complex than expected. Water vapor is the greenhouse gas that is most important.

a reply to: pteridine

Water vapor content is temperature dependent. CO2 content is not.

originally posted by: Phage
a reply to: pteridine

Water vapor content is temperature dependent. CO2 content is not.

Regardless of what it depends on, it has a greater effect. As temperature increases, so does water vapor. Further, methane hydrates decompose and cause further heating which vaporizes more water, and so on.

a reply to: D8Tee

The problem with global warming sea level rise is the socially accepted information.
Fear mongering or not, most people seem to still worry about losing our beaches when they hear about "an island *somewhere* that's going under/being hit by rising sea levels"

Now, I do believe that sea level is rising; it does rise and fall.. But so does the land crack and shift. In fact earth and water are constantly in flux.

I'm merely an armchair scientist, probably not the greatest... Possibly the worst!

A few things I wonder about sea level rise... Water doesn't only fall into the sea, and more and more is sequestered by man away from natural water sources. Another random thought is that if the weight of the polar ice caps squashes the Earths shape, then, the waters released to the sea would reform the earth as the weight is redistributed.

All that in mind, sea level could rise or fall..
In my opinion I don't see any appreciable difference, any deviation from nature's "normal" may be influenced by the effects of man, and while I feel it is more natural than we assume, the only thing man can really do is strive to work better with the earth, and water.

I am glad that at least the nauseating bickering over man's role over the past couple decades has started to cease, it almost seems like real solutions are close at hand.


But, I mean, really, like it matters
I mean, Extinction Level Event meteor or some-such aside, the glaciers will be back!
Sneaky bastards

originally posted by: D8Tee
a reply to: pteridine

When Greenland melts, places as far away as Norway and Scotland could actually see the sea level fall by as much as 50 meters.

I find that rather... shall we say, incredible? Is there any peer reviewed sources?

This may be the one. I don't have access to it from home.

Kopp, R.E., J.X. Mitrovica, S.M. Griffies, J. Yin, C.C. Hay, and R.J. Stouffer, “The Impact of Greenland Melt on Regional Sea-Level: A Partially Coupled Analysis of Dynamic and Static Equilibrium Effects”, Climate Change, 103, 619-625, 2010.

a reply to: pteridine

I see the 50 meters repeated with the same incredulity on several other sites. Maybe the professor left out a zero in the gravitational constant lol. It was designed as a thought experiment, I'll delve into it more when I get my net out of it's limited bandwidth state next month.

harvardmagazine.com...

Fame of the academic variety came early to Mitrovica and mushroomed about a decade ago, when he reminded people what happens to local sea levels in the vicinity of a melting ice sheet, like those covering Greenland and Antarctica. The effect was first described a hundred years ago, but “people had forgotten how big it was,” he says. “It’s big.” If Greenland’s ice sheet melted entirely, sea level would fall 20 to 50 meters at the adjacent coast. That’s counterintuitive, but the ice sheets are so massive (Greenland’s ice, one-tenth the size of the Antarctic ice sheets, weighs on the order of 3,000 trillion tons) that two immediate effects come into play. First, all that ice exerts gravitational pull on the surrounding ocean. When an ice sheet melts, that gravitational influence diminishes, and water moves away from the ice sheet, causing sea levels to drop as far as 2,000 kilometers away. (The drop is most pronounced close to the glacier, because gravity’s effects dissipate with distance.) But because the sea level has fallen where the ice sheet melted, it rises everywhere else beyond that 2,000-kilometer boundary, and on distant shores this rise is far greater than the global average.

It's discussed further here but I can't watch the video.
www.physicsforums.com...

a reply to: Phage

Good morning Phage.

How so? Because that's how force works. If sea level is increasing due to a gravitational anomaly, that gravitational anomaly is negative. More 'downward' force (gravitational attraction) would tend to cause sea level in the affected region to drop, not rise. A mascon under New Zealand would result in a drop in New Zealand sea level. Therefore, if sea level is increasing relatively in New Zealand due to a mascon, that mascon is located on the other side of the planet.

If a mascon is thusly located, it would be close to England, resulting in an increased gravitational field in England and a resulting relative sea level drop. Is sea level dropping in England?

TheRedneck

a reply to: D8Tee

50 meters is absolutely ridiculous. Someone dropped the ball proofreading. Anything above 50 micrometers is laughable, and I would expect something like 50 nanometers.

Things like this being taken seriously is exactly why I discount the whole theory.

TheRedneck

originally posted by: TheRedneck
a reply to: D8Tee

50 meters is absolutely ridiculous. Someone dropped the ball proofreading. Anything above 50 micrometers is laughable, and I would expect something like 50 nanometers.

Things like this being taken seriously is exactly why I discount the whole theory.

TheRedneck

50 micrometers in the range of the thickness of a human hair. Maybe you meant to suggest 50 centimeters.