If the polar glaciers melt, will the sea level really rise, which feels contrary to a physical phenomenon?
Langya Academy Notes 2024-04-27 06:00 Shandong
We all know that after the water freezes, the volume will become larger, and we also know that the tip of the iceberg, the water surface is the majority, however, after the ice of the water, the volume will decrease, and the shrinkage rate generated by the huge volume can no longer offset the volume of the part above the sea level, and there are related experiments, fill the bucket with water, put a large piece of ice, after the ice, the water will not overflow, the so-called no glacier melting will lead to sea level rise, is it really credible,
Cloud Dance Sky City:
This is the Greenland Ice Sheet, mostly within the Arctic Circle, and on land, not floating on the sea.
The picture below shows the Antarctic ice sheet, most of which is also on land and does not float on the sea.
Long Luchen:
Allow me to borrow a paragraph from how to solve a real problem unrealistically
The following is adapted from how to (I'll put the original sentence at the end)
The simple question is that if the glaciers in the Antarctic are melted, the water level in the Northern Hemisphere will have the greatest impact (it will rise) and vice versa, while the water level in the South Pole will fall
It is gravity that causes this strange effect. The ice is heavy, and when it is piled on the ground, it pulls the ocean a little towards itself. When the ice melts, the average height of the sea level rises, but because the sea is no longer pulled so hard towards land, the sea level actually falls in the surrounding areas where the ice melts
When the Antarctic ice sheet melts, sea levels rise most in the Northern Hemisphere. And when Greenland's glaciers melt, Australia and New Zealand see the most sea level rise.
original
cinna：
The subject's idea is right, but there is no need to analyze it so troublesomely:
In a word, according to the law of buoyancy, the buoyancy of an object immersed in water is equal to the volume of water it expels (as Archimedes found when he bathed), so the volume of water that becomes when the ice melts on the surface of the water is exactly the part of the water where it was originally in the water, and the height of the horizontal plane does not change.
But the survey now does find that sea levels are rising every year due to global warming due to:
1. The density of seawater becomes higher when the temperature is high;
2. The ice in the land melts. There is mainly ice on Greenland, and most of the ice in Antarctica is also an ice sheet covered in bedrock, a very thick layer, and only when the ice sheet moves outward becomes an iceberg floating on the surface of the sea;
3. The ice shelves outside the ice sheet melt and disintegrate, causing the ice sheet to enter the ocean faster.