How did all that ice get above sea level in Greenland?

Question

Ice floats, so, unless the sea level was many feet higher, the ice would have had to have been lifted into place some other way. Scientists have said that the amount of water in Greenland, if melted, would raise the sea level several inches to several feet. This is a lot of ice. Other melting of ice would not contribute to sea level rising since the ice is already in the water and displaces the equivalent amount of water already.

I am a Professional Civil Engineer in Orlando, FL ( http://www.mckeonengineering.com ) and have pondered this question for a while now.

We are talking about frozen water on a land mass.

BTW, I have already considered snow and precipitation and other things of that nature and it just doesn't add up.

As of 4:30am (yes, I am actually awake, God help me), none of the answers have been really helpful.

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Answer 1

Millions of years ago the world was completely free of ice (and considerably warmer than it is now). As the planet cooled through a combination of natural cycles ice began to form, although it may seem strange we've been heading into an ice age for a little over 50 million years now.

The ice that can be found in Greenland, Antractica, the Arctic, mountain ranges etc all comes from the same source - precipitation. Through the normal hydrological cycle, water evapourates from the seas and oceans, cools as it rises and subsequently falls as raain, or if it's cold it falls as snow.

In the world's colder regions the snow never melts, it just accumulates over thousands, even millions of years. Through the effects of gravity and consolidation under the weight of subsequent snow it is compressed into ice.

In mountainous regions the ice is quickly (comparatively speaking) removed from the mountains through glacial flow. Eventually the glaciers reach lower altitudes where temperatures are warmer and the ice melts. Several of the worlds major rivers start life this way including the Indus, Ganges and Yanktze.

The ice sheets of Greenland and Antractica behave in a similar manner to the glaciers (which is effectively what they are) but the process is much slower and is often referred to as glacial creep. In time the snow that fell and turned to ice will reach the periphery where it melts due to higher temperatures, collapses into the sea or is melted by the (sometimes) warmer sea water.

You mentioned the melting of ice in Greenland, there's 2.62 million cubic kilometres (2.41 quadrillion tons) of ice here, were it all to melt then sea levels would rise by 6.55 metres (21 feet). The biggest land based ice mass is found in Antractica, it's effectively divided into three (East, West and Peninsular) and were all this to melt then sea levels would rise 73.42 metres (240 feet). It's the Arctic ice which is floating (together with other sea ice, pack ice, ice shelves etc) and as you pointed out, these are floating and could melt completely without affecting sea levels.

Just to add, in some places there has been uplifting which has raised the levels of the ice higher above sea level (most notably in the mountains) but the massive accumulation of ice is such that it depresses the ground beneath it. In some places the base of the ice sheets is below sea level even though it's on land.

Answer 2

Snow.

"BTW, I have already considered snow and precipitation and other things of that nature and it just doesn't add up."

How so? Go talk to a fellow engineer or scientist, maybe they'll have better luck explaining to you.

But it snows near the poles. And it was below freezing most of the time, so that only some of the snow melts. The weight of snow piling on top of other snow turns it into ice.

Now that it's warming, some of that vey old ice is melting.

Answer 3

I'm surprised you'd ask. Thae mechanism is well known. In the Artic regions for many thousands of years the average temperatures have been cold enough so that all of the snowfall does not melt. Consequently, year after year, millineum after millenium, the snow pack (which turns to ice as it is crushed under the wight of latersnowfalls) builds up.

That accumulation process continues until one of two things happens. ONe, the pressure of the acumulated ice forces glacier flows sufficient to dump enough ice (in the form of icebergs) into the ocean to balance new snowfall--creating an equilibrium state. Two is if the average temperature rises enough to tip the balance and cause more annual melting than new snowfall replaces--as is happening now due to global warming.

Answer 4

Millions of years of snowfall. All glacial ice is derived from snowfall, which falls and packs down upon itself over and over. Eventually the weight compacts it into ice, and in Greenland's case, it has been in the artic region for millenia so the snow buildup to produce the immense ice sheet has been almost continuous.

Answer 5

I suspect that you have calculated the volume of ice on Greenland, converted it to volume of water, and spread that volume over the area of the oceans to get the rise in height, and it doesn't add up? Have you considered the expansion in the volume of ocean water due to a rise in the average temperature of the oceans?

Answer 6

Yes it did get lifted many feet higher into place some other way, it's called snow, and it took thousands of years to build up that much snow to be compressed into that much ice.
Professional engineer indeed.

Answer 7

Its been millions of years of compressed snow. Thats a lot of water, therefore the level of water in Greenland has risin.

Answer 8

precipitation

evaporation in other places
then
,hail snow .

the ice man came

Answer 9

Hope your boss doesn't read this....you're fired..