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Dan19_82 t1_jb4k80z wrote

Reply to comment by ParatusLetum in During the last ice age, how long would it have taken for the ice sheets to form? by CDNEmpire

The one thing I've never understood is, isn't Antarctica considered a desert because of complete lack of snowfall / precipitation. I've always wondered how anything builds up unless it's incredibly slow.

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PigHillJimster t1_jb4rigr wrote

A dessert is defined as a place where there is less than 25 cm of precipitation per year, so yes, Antarctica is considered a desert.

There are many other regions that fit this description that are very cold.

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Busterwasmycat t1_jb5dqbn wrote

rate doesn't affect the fact that accumulation is happening, what matters is that addition exceeds removal over time. How long it would take to make a thick pile, though, that does matter on rate, or more particularly the size of the difference between addition and removal (high addition rates combined with high removal rates would still result in slow accumulation, same as if both were low). The Antarctic has been accumulating ice for maybe as much as 25 million years, or about there, and it probably wasn't such a desert for all that time.

The earth did not go from "Antarctica is a temperate forest and grassland" to "Antarctica is a frozen desert of ice" overnight.

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7eggert t1_jb4s224 wrote

As I understand, it's rarely snowing because it doesn't evaporate. Off cause a little bit of water vapor will also come from the outside and - because cold air can't contain it - fall down sooner or later. In the other direction there are glaciers transporting the snow / ice back to the ocean.

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