glacier: large masses of snow, recrystallized ice and rock debris that accumulate in great quantities and begin to flow outwards and downwards under the pressure of their own weight.

snowfield: large areas covered with snow which are created during years when more snow falls than melts.

accumulate: what happens when snow falls faster than it melts and it piles up.

rock flour: the product of glaciers scraping away mountains and rock material and grinding it into a fine dust.