Glaciers

two requiremements for something to be considered a glacier

1) ice form through metamorphism

2) ice needs to be moving

Conversion to Ice

snow accumulates

after two yrs turns into firm then ice

firm

intermediate step b/w snowflakes an ice

- ice pellets

- recrystallization process

cirque

flowing ice streams restricted to an amphitheater-shaped depression in

-can become a valley glacier once it becomes too big

valley glacier

- streams of ice that flow down valley well beyond the cirque

ice sheets

huge , broad flowing ice masses that are not confined to valleys,

ice accumulates to massive thickness

Temperate glaciers

ice is at/ near melting pt.

polar sub glaciers

ice mass is below pressure melting pt except for summer melting

polar high glaciers

ice mass that is below pressure melting pt. at all times

active glacier

hugh rates of ice movement

passive glacier

low rates of ice movement

dead glacier

no discernible internal ice flow

accumulation

things coming in, through precipitation, avalanches and frozen meltwater

ablation

losses; through melting, evaporation, wind, sublimation, calving(cunk of ice breaks glacier)

- typically see ablation at low elevation , edges are zone of ablation

regelation

refreezing; pressure melting at base of glacier but some places pressure is lower and water can refreeze

classification systems for glaciers

morph, dynamic, thermal

glacier hardness

soft