0
   

Hey Farmerman, Could Icemelt Shift Earth's Rotation, Moving Water Northward?

 
 
Reply Fri 6 Feb, 2009 09:25 am
Icemelt Could Shift Earth's Rotation, Moving Water Northward
February 5, 2009

WASHINGTON " Long-term sea level increases that could have a devastating effect on southern Florida and highly populated coastal areas may be even larger than once thought, a report suggests.

Some studies have suggested that melting of ice in Antarctica and other areas could raise sea levels by 16 feet to 17 feet over the long run, a potential threat to coastal areas such as Washington, D.C., New York City and California.

But a report in Friday's edition of the journal Science warns that factors not previously considered could one day boost that increase to up to 21 feet in some areas.

The study did not list a time frame for such a dramatic change. But co-author Peter Clark, a geoscientist at Oregon State University, stressed that they "aren't suggesting that a collapse of the West Antarctic Ice Sheet is imminent."

The most recent International Panel on Climate Change report estimated sea level rise of up to 3 feet by the end of this century.

"People have been trying prepare for sea level rise for some time, it's not a new issue," Clark said, noting that the U.S. Fish and Wildlife Service and U.S. Geological Survey are holding a meeting in San Francisco on the effects of coastal change.

Earlier research has focused on melting ice adding water to the oceans and on thermal expansion of sea water in a warmer climate over long periods of time.

In the new report geophysicist Jerry X. Mitrovica and physics graduate student Natalya Gomez of the University of Toronto, Canada, and Clark, say other factors need to be considered.

Story continues below

_When an ice sheet melts, its gravitational pull on the ocean is reduced and water moves away from it. That means sea levels could fall near Antarctica and rise more than expected in the northern hemisphere.

_Antarctic bedrock that currently sits under the weight of the ice sheet will rebound from the weight, pushing some water out into the ocean.

_The melting of the West Antarctic ice sheet will cause the Earth's rotation axis to shift, potentially moving water northward.

"The net effect of all of these processes is that if the West Antarctic ice sheet collapses, the rise in sea levels around many coastal regions will be as much as 25 per cent more than expected," Mitrovica said in a statement.
--------------------------------------------

On the Net:
Science: http://www.sciemcemag.org
  • Topic Stats
  • Top Replies
  • Link to this Topic
Type: Discussion • Score: 0 • Views: 2,047 • Replies: 9
No top replies

 
farmerman
 
  1  
Reply Fri 6 Feb, 2009 09:30 am
Dont ask me, the story sounds reasonable though. When the Glaciers were melting the actual rebound of the crust , accentuated by rotational drag, did keep the Northern Hemsiphere from sinking belwo the wves. There are so many counteracting forces involved that a decent tidal drag model still is only in the test drive stage.
0 Replies
 
hamburger
 
  2  
Reply Fri 6 Feb, 2009 09:46 am
@BumbleBeeBoogie,
did you see my post : http://able2know.org/topic/44061-615#post-3563211

as the scientist being interviewed on CBC said : "more studies are needed" .

it seems to me that we have paid more attention to the moon (and sunk a lot of many into those space projects) than we have to many things going on on our own earth .
trudging through antartica doesn't sound nearly as exiting as zooming through space .
watching the controller say "LIFTOFF" makes more hearts beat than someone getting a mile closer to the south-pole .
hbg
0 Replies
 
rosborne979
 
  1  
Reply Fri 6 Feb, 2009 09:56 am
@BumbleBeeBoogie,
Anything is possible. Some things are probable. Many things are minimal (in the scheme of things).
0 Replies
 
hamburger
 
  1  
Reply Fri 6 Feb, 2009 01:22 pm
@BumbleBeeBoogie,
how about a reversal of the poles ?
the actual location of the north-pole is drifting constantly and pole reversals have taken place in the past a/t NASA .
apparenttly not too much to worry about ; just hang on to your bed or the nearest lamp-post until it's over - should be fun Shocked Wink

see : http://www.nasa.gov/vision/earth/lookingatearth/29dec_magneticfield.html
farmerman
 
  1  
Reply Sat 7 Feb, 2009 06:03 am
@hamburger,
We use pole drift and reversals as a geo-"clock" when we do site work. Often its possible to extract and measure (in situ) the remnant magnetism of rocks and soils that have either been burned in a range fire, or hit with volcanic ash and hot "Nuee ardente" The magnetism gets baked away as the rock reaches a specific temp for the minerals and then, as the rocks cool, they are imprinted with new magnetic directions. Of course we have to take into account whether the rocks have been folded and which way etc. Its a good dating trick since the poles have reversed about 200 times since the Cretaceous.
Its like having a little compouter clock handy at almost every outcrop. The usefulness dissipates older than that however because of remobilization of strata and erosion etc.
(nothings perfect).
My nephew is researching tidal drag using diffusion of deep sea currents near the poles. Its rather detailed and tedious work that gets my ADD going when I learn that theres probably no application to the research other than looking at climate trends.
hamburger
 
  1  
Reply Sat 7 Feb, 2009 03:44 pm
@farmerman,
farmerman :
interesting observations !
i receive a german magazine every once in a while dealing with "what's new in german science , politics ... " .
some years ago the university of tuebingen published several studies dealing with reversal of the poles in the magazine (they speculated it might disrupt radio and satellite communications , but didn't believe any major problems would result) .
they also did some studies re. gulfstream cooling and possible reversal of the warm current . their conclusion was such reversal would cause rapid cooling in northern europe but result in other areas of the earth getting much warmer .
not being any kind of a scientist , i can only read it - and i'm fascinated by such studies .
take care !
hbg
farmerman
 
  1  
Reply Sat 7 Feb, 2009 05:25 pm
@hamburger,
Since polar reversal takes place over a geologically short time, such as a few thousand years, we may be missing some really significant results from our standpoints (Humans that is). A major polarity reversal, the Brunhes, occured about 70 to 75 K ybp. This was also the time that the Toba eruption was blamed for a major decrease in H sapiens and the disappearnace of H sapiens idaltu. I ask, was the Toba eruption, or prhaps a magnetic polar reversal acting as a two part whammy? During polar reversals, as the magnetic intensity and declination change, solar radiation may intensify to the point where it may become lethal to unprotected drmal surace on animals with sweat glands (like humans and horses and apes).
Its equally possible that, during the initiation of the Brunhes, humans were getting zapped and were dying from melanomas.
hamburger
 
  1  
Reply Sat 7 Feb, 2009 07:17 pm
@farmerman,
farmerman :
pls advise so that i may crawl into a mineshaft BEFORE a pole reversal !
should consider moving to northern ontario - plenty of abandoned mines up there .
hbg

the "denison mine" site at elliot lake is now a retiremant comunity - perhaps the place to move to - housing is quite inexpensive there (the mining company still owns the property and subsidizes housing - they hope to eventually re-open the mine ) .
we visited there years ago when ehbeth was working out of sudbury - a nice place , but a bit far away from "civilization" .

http://www.mndm.gov.on.ca/mines/mg/mgimages/denison1.jpeg
0 Replies
 
georgeob1
 
  1  
Reply Sat 7 Feb, 2009 07:40 pm
The magnetism of the earth and the pole reversals associated with it, as well as various local magnetic anomolies, are all associated with the convective flow of molten, electrically charged magma beneath the earth's crust. The magma flow is only partly understood, but such flows are known to be both unstable and subject to chaos (i.e. unpredictable).

The (geologically) rapid pole reversals that farmerman describes are clear enough from the geological record in many areas of the earth including sea floor data. Farmerman noted the increase in cosmic radiation at the surface of the earth attendant to the weakening of the earth's magnetic field during such reversals - even though they have in the past proceeded quickly (on a geological time scale). The bottom line here is that biological survival on the earth's surface is dependant on the sustained effect of the planet's magnetic field in deflecting solar radiation and concentrating it at the poles. There is, in principle nothing known that could prevent the eventual significant weakening or breakup of our so far fairly coherent two pole magnetic field as a result of some chaotic disturbance in the convective flow of the molten core material. I doubt that even Al Gore could do it.

The earth is not and never has been in equilibrium.
0 Replies
 
 

Related Topics

 
  1. Forums
  2. » Hey Farmerman, Could Icemelt Shift Earth's Rotation, Moving Water Northward?
Copyright © 2022 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.03 seconds on 05/16/2022 at 08:07:17