The When and The Why?

When did the Glaciers Occur?

The WHEN question is one of the 5Wquestions that I have set out for myself to answer. However doing my research. I have realised that this is a toughie, as there is no answer for this.

As previously stated Glaciers currently cover 10% of the world's land surface, however this Glacier Ice has been on the land surface for hundreds of years and it is only being sustained by annual precipitation.
Majority of the Glaciers that is currently around may have originated from the Last Ice Age, when Glaciers covered 32% of the land area. As the world has warmed up, the Ice has been melting. (this issue will be looked at in a later post), this is when Isostatic adjustment occurs. As the pressure is released from the shrinking Ice, the land is rising, as the pressure from the original Ice pushed the land surface down.



Why Do Glaciers Form

I have actually answered this question in my section of  'What is a Glacier', however I am going to go through it again. As repetition can sometimes be a goo thing.

When snow falls over hundred years and the climate of the area allows the snow to settle without melting or evaporating the snow. The pressure of the snow compresses together and forms a large Ice mass.

When Glacier Ice appears blue, it means that the ice is very dense. Years of compression makes the ice denser, as it pushes out any air pockets between the ice crystals. This dense ice does absorb all the colours of the spectrum but it primarily reflects Blue as there are very little air pockets.