介绍:
30. Glaciers冰川
[00:02.24]Glaciers are formed in places
[00:05.40]where the temperatures are extremely cold.
[00:07.68]This could even include places that are at sea level,
[00:11.47]but are mostly places that are high up on mountains.
[00:14.88]In such cold places it snows most of the year.
[00:18.66]This snow will settle down and when it snows again
[00:22.23]the lower layer of snow gets compressed.
[00:24.98]Every time it snows,
[00:27.02]the below layers will compress more,
[00:29.68]finally turning into hard ice.
[00:32.28]This ice is what forms the glacier.
[00:35.31]When the temperature rises slightly,
[00:38.20]the outer edges of the formed glacier
[00:40.64]and fresh snow will melt.
[00:42.74]For a glacier to form
[00:44.70]and sustain itself it is of prime importance
[00:47.91]that the amount of snow that falls on it
[00:50.16]must be more than the amount of glacier that has melted.
[00:53.38]This is the only way in which the glacier
[00:56.80]will be able to maintain itself
[00:59.00]and keep increasing in size year after year.
