Plate Tectonics - Melting Polar Caps - Earthquakes - Volcanoes

[SpaceShark]

I stared thinking what would really happen if the polar ice caps really melted away - Everyone all ways focuses on the effects of the rising seas - But I started thinking - what other effects could happen

 

If water weighs 62 lbs a cubic foot - so when you start displacing billions upon billions of metric tons around - Shit is going to happen - My guess is the pressure released from the polar caps will cause frequent earthquakes and volcanic eruptions

 

I believe a continental plate could crack under all that stress - when it has to realign itself to match for the new external gravitational pressures

 

So my question is - Do ice caps have a force in moving the plate tectonics?

 

SpaceShark

[Simpleton]

I guess that there certainly is a very high probability that it would encourage both. I expect will comment and enlighten us some time along the way.

[JohnB]

Short answer: No, probably not.

 

Longer answer: Sea level rises and falls and it is important to keep things in perspective. Sea level during the last Glacial Maximum, circa 20,000 years ago was around 400 feet lower than it is today.

 

The plates didn't break under the increased strain of an extra 400 ft of water, so it's unlikely that an extra foot or so will make any difference.

 

That is not to say that the change from Glacial to Interglacial didn't cause earthquakes. The Parvie fault area in Scandinavia was caused by glacial "rebound" and is a beaut. There were many earthquakes in this region due to the land rising after the ice was gone. Scandinavia was lowered by circa 800 metres by the weight of the ice.

 

I haven't seen figures for the US region but I would expect something similar there.

 

The bottom line is that if the land rising by hundreds of metres and the sea rising by hundreds of feet didn't cause mass destruction of the plates, why would you expect a couple of feet of water to do anything?

 

If we look at the last 20,000 years;

 

The Earth constantly changes and Sea Levels rise and fall by greater amounts than most people think. The Swedish town of Gammelstad "Old Town" was originally on the coast. During the 17th Century the people moved to Nystan "New Town" on the new coast. Gammelstad is now some 10 km from the coast.

 

So no, there is no reason to believe that the plates will break due to a foot or two of sea level rise.

 

Cheers.

 

PS. To get an idea of previous movements read a bit about "Isostatic Rebound" and you'll get an idea of just how much the plates have moved and flexed in the last 20,000 years.

[SpaceShark]

From ewire dot com

 

"Richard Guy in his new book "The Mysterious Receding Seas" Puts forward conclusive proof that our Planet Earth is expanding. The expansion process dictates that seas recede from shorelines worldwide making the landmass appear to rise. Guy states that the isostatic rebound theory is an error in geological interpretation. For over a century geologists have propounded that the land mass rises from the ocean by a process called isostacy.

 

This is because sea level datum has always been accepted as fixed in elevation. All levels on land are taken from sea level datum. This acceptance of sea level datum, as a constant, is the key factor in the geological misinterpretation. This misinterpretation gave rise to the Isostatic Theory.

 

The land mass does not rise, Guy states, but rather the sea levels fall creating the illusion that the land mass rises. Guy points out that sea levels have been falling for millions of years.

 

We fail to recognize this because successive generations accept the sea level where they find it. Each new generation is totally unaware that sea levels fall and still continue to fall. Guy cites examples from early history and the bible from Noah and the Ark to the Exodus. His findings on the Exodus are quite amazing. Guy has uncovered facts about the Exodus that no other scholar has unearthed. You will be totally convinced after reading his book. Guy proves his points clearly and convincingly and takes you into ancient history to show why all ancient civilizations evolved in the high mountains around the world.

 

The Egyptian, Mesopotamian, Indus, Tibetan, Chinese, Incas and Aztecs all evolved at high elevations. Guy tells you why. 'The Mysterious Receding Seas" will take you back into history on an amazing journey."

 

If the plates are breaking a part - I would think this could be a contributing factor

[Sisyphus]

Puts forward conclusive proof that our Planet Earth is expanding.

 

No, he doesn't. That's really, really ridiculous. See the first review on Amazon of this book (listed as fiction!):

 

http://www.amazon.com/Mysterious-Receding-Seas-Richard-Guy/dp/1413439918

[JohnB]

SpaceShark, such an incredibly stupid "theory" could only be put forward by someone whos knowledge of history is slightly inferior to that of my cat.

 

We have evidence of submerged cities from India, the Mediterranean and possibly Cuba. If the sea level was constantly dropping, why are they under water? If his "theory" was in any way correct, there would not be sunken cities, would there?

 

If you wish to make a case for this "theory", then by all means start a thread in "Speculations" and go for it, but please do not pollute serious threads with this rubbish.

[OSHMUNNIES]

For over a century geologists have propounded that the land mass rises from the ocean by a process called isostacy.

 

You've confused isostacy/isostasy with "Neptunism"(http://en.wikipedia.org/wiki/Neptunism), which is a theory that hasn't been taken seriously since the early 19th century. Isostacy/isostasy is nothing more than Archimedes Principle applied to landmasses...its pretty simple.

[OSHMUNNIES]

I stumbled across an article today from geology.com that I think may answer your original question, spaceshark. Setting aside that stuff about sea levels and Exodus, NASA's GRACE (Gravity and Recovery Climate Experiment satellite system) shows that the massive unloading stress from ice melt in Greenland is contributing to as much as 1 cm/year in uplift.

Check it out: http://geology.com/press-release/greenland-ice-sheet/

[SpaceShark]

I stumbled across an article today from geology.com that I think may answer your original question, spaceshark. Setting aside that stuff about sea levels and Exodus, NASA's GRACE (Gravity and Recovery Climate Experiment satellite system) shows that the massive unloading stress from ice melt in Greenland is contributing to as much as 1 cm/year in uplift.

Check it out: http://geology.com/press-release/greenland-ice-sheet/

 

Thx Oshmunnies - i imagine the speed of the melting glaciers would be a factor too - but the idea of the earth being capable of expanding and contracting intrigues me