http://www.physorg.com/news69600618.html
Why all the fuss about the Arctic Ocean falling. In Physics Today, for Jan 2005, in letters to the editor, I predicted that that is exactly what is supposed to happen under the laws of physics whent he floating sea ice melts.
Anyone who ever got out of a hot shower wet, or added ice cubes to a glass of Coca Cola can tell you why. Heck it is 8th grade high school physics, so why is everyone surprised.
When floating sea ice melts, the water level will FALL; it will not RISE, and it won"t stay the same (Archimedes); there"s no mystery to solve.
Actually melting of floating sea ice would predict movement in the opposite direction due to the difference in density of fresh vs salt water,
Its actually quite surprising in that the global sea level is supposedly going up by 9 mm per year, mainly due to expansion.
Arthur
Its actually quite surprising in that the global sea level is supposedly going up by 9 mm per year, mainly due to expansion.
Arthur
QUOTE (adoucette+Feb 13 2007, 04:10 AM)
Actually melting of floating sea ice would predict movement in the opposite direction due to the difference in density of fresh vs salt water,
-once again demonstrating either:
- attempt to mis-lead/distract.
- total lack of knowledge since the melting of floating sea ice has a relatively insignificant effect compared to the melting of the land based ice shelves.
QUOTE (adoucette+Feb 13 2007, 04:10 AM)
Its actually quite surprising in that the global sea level is supposedly going up by 9 mm per year, mainly due to expansion.
QUOTE (Smithy+Feb 13 2007, 01:09 PM)
-once again demonstrating either:
-supposedly? But Arthur isn't trying to deny it, is he?
Smithy (posts)
Actually I'm well aware of the VERY SLIGHT impact if all the FLOATING ice melts.
See:
http://forum.physorg.com/index.php?showtop...ndpost&p=164386
However, though very slight, still that impact would be an INCREASE in sea levels.
Which is why my statement
- attempt to mis-lead/distract.
- total lack of knowledge since the melting of floating sea ice has a relatively insignificant effect compared to the melting of the land based ice shelves.
-supposedly? But Arthur isn't trying to deny it, is he?
Smithy (posts)
Actually I'm well aware of the VERY SLIGHT impact if all the FLOATING ice melts.
See:
http://forum.physorg.com/index.php?showtop...ndpost&p=164386
However, though very slight, still that impact would be an INCREASE in sea levels.
Which is why my statement
QUOTE (arthur+)
melting of floating sea ice would predict movement in the opposite direction
was correcting Seafang who said
QUOTE (Seafang+)
When floating sea ice melts, the water level will FALL
So Smithy, could you please explain where there is an attempt is to mis-lead/distract?
As to my use of 'supposedly' well that is simply an indication of our limitations in our ABILITY to accurately measure GLOBAL SEA LEVEL to this resolution over short time spans.
As this article points out, we now have evidence that one part of the INTERCONNECTED OCEANS is DROPPING at 2 mm per year.
This situation can not logically co-exist with the statement that the Oceans are ALSO rising at 9 mm per year, well at least not without explaining how the two are related.
Arthur
So Smithy, could you please explain where there is an attempt is to mis-lead/distract?
As to my use of 'supposedly' well that is simply an indication of our limitations in our ABILITY to accurately measure GLOBAL SEA LEVEL to this resolution over short time spans.
As this article points out, we now have evidence that one part of the INTERCONNECTED OCEANS is DROPPING at 2 mm per year.
This situation can not logically co-exist with the statement that the Oceans are ALSO rising at 9 mm per year, well at least not without explaining how the two are related.
Arthur
Sir,
If water seeks its own level, why are locks needed in the Panama Canal? Are the existing Oceans at the same level?
Keeping your reply in layman's language would be appreciated.
Jay
faynjim@comcast.net
If water seeks its own level, why are locks needed in the Panama Canal? Are the existing Oceans at the same level?
Keeping your reply in layman's language would be appreciated.
Jay
faynjim@comcast.net
They Oceans are not at the same level. In fact the entire concept of a Global Sea Level is somewhat misleading.
The Pacific water level around Panama is on average about 3 meters higher than the water level on the Atlantic side.
But this 3 meter difference is actually only about 1/5th of the ~15 meters that the Oceans vary in their actual height around the globe at any given time.
The reasons have to do with a great number of factors:
Gravitational attraction of other bodies (Moon, Sun, Planets) combined with orbital variations. (it takes ~ 18 years of measuring at a given spot on the earth to allow the largest of these to be canceled out)
Gravitational attraction of the Earth (varies from place to place)
Centrifugal force caused by different rotational velocities at varying latitudes.
Wind (constant winds can cause water to pile up, higher if there are surface features that the wind is blowing against)
Currents (like wind, can also cause water to "pile up")
Temperature of the water in the area.
and
When it comes to measuring sea level, waves (wave height causes water to appear higher than it really is) and local movement of the ground one is measuring the sea level from is also a factor as rising land (i.e. from Glacial Rebound) causes an apparent drop in the sea level while falling land (i.e Subduction zone around Tonga) makes the sea level appear to rise.
Arthur
The Pacific water level around Panama is on average about 3 meters higher than the water level on the Atlantic side.
But this 3 meter difference is actually only about 1/5th of the ~15 meters that the Oceans vary in their actual height around the globe at any given time.
The reasons have to do with a great number of factors:
Gravitational attraction of other bodies (Moon, Sun, Planets) combined with orbital variations. (it takes ~ 18 years of measuring at a given spot on the earth to allow the largest of these to be canceled out)
Gravitational attraction of the Earth (varies from place to place)
Centrifugal force caused by different rotational velocities at varying latitudes.
Wind (constant winds can cause water to pile up, higher if there are surface features that the wind is blowing against)
Currents (like wind, can also cause water to "pile up")
Temperature of the water in the area.
and
When it comes to measuring sea level, waves (wave height causes water to appear higher than it really is) and local movement of the ground one is measuring the sea level from is also a factor as rising land (i.e. from Glacial Rebound) causes an apparent drop in the sea level while falling land (i.e Subduction zone around Tonga) makes the sea level appear to rise.
Arthur
QUOTE (Jim Martin+Mar 12 2007, 12:51 AM)
Sir,
If water seeks its own level, why are locks needed in the Panama Canal? Are the existing Oceans at the same level?
Keeping your reply in layman's language would be appreciated.
Jay
faynjim@comcast.net
Also, disregarding the larger discussion going on here, the Panama canal needs locks because the ships are climbing hills as they go. The bulk of the Canal is about 85ft above the mean sea level. There is a nice map of this at www.lib.utexas.edu/maps/historical/shepherd/panama_canal_shepherd.jpg
At the bottom of the map is a cross section showing elevation changes.
If water seeks its own level, why are locks needed in the Panama Canal? Are the existing Oceans at the same level?
Keeping your reply in layman's language would be appreciated.
Jay
faynjim@comcast.net
Also, disregarding the larger discussion going on here, the Panama canal needs locks because the ships are climbing hills as they go. The bulk of the Canal is about 85ft above the mean sea level. There is a nice map of this at www.lib.utexas.edu/maps/historical/shepherd/panama_canal_shepherd.jpg
At the bottom of the map is a cross section showing elevation changes.
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