I really enjoy watching these massive sampling of ice and snow, which mainly lies above the mean zero isoterm.   Precipitation ascertain growth, and sunshine  radiation,  warm air melting and  latent heat from the bedrock adds up for the melting.  The balance between,  results in the white cover,  the  blue Ice and all the strange, impressive shapes. Longterm "rivers" of descending Ice, make the ice move rocks and produce  beds and dams like moraines through thousanads of years.