十万个为什么·科学启蒙30篇（1）
25 / 30
正在校验访问权限...
Why Do Icebergs Float While Most of the Ice Is Hidden?
为什么冰山能漂浮，而大部分冰却藏在水下？
-
Icebergs float because ice is less dense than liquid water.
-
When water freezes, its molecules form a loose crystal structure that takes up more space.
-
This makes ice about 9% lighter than the same volume of seawater.
-
So only about one-tenth of an iceberg shows above the surface.
-
The rest stays submerged due to buoyancy and the balance of forces.
-
Salt in seawater increases its density, helping icebergs stay afloat longer.
-
Melting icebergs don’t raise sea level much because they’re already displacing their weight.
-
Scientists use satellites to track iceberg size and movement carefully.
-
Understanding this helps us predict ocean current changes and climate impacts.
-
Even small temperature shifts can affect how fast icebergs break apart.