e)fluctuations of the glacier terminus (front):* terminus retreat- accumulation is greater than ablation* terminus advance- ablation greater than accumulation* other terms-response lags- time it takes for the effects of an increase or a decrease in accumulation above the equilibriujm line to change the terminus location (longer for large or polar glaciers)-calving- breaking off of icebergs from the front of a glacier that terminates in deep water; produces icebergs (fjord glaciers)How Glaciers Movetypes of movement:* internal flow/creep- movement within ice crystals due to high stress from weight of overlying snow and ice-crystal axes alligned-crevasse- deep gaping fissure in glacier surface caused by uneven ground* basal sliding- movement of a body of glacier ice, by sliding across the underlying rocks or sediments (not polar glaciers)other considerations:* velocity- faster in uppermost center (same as rivers)* directions of flow- snow/ice initially flows downward, then downglacier, and finally upward toward the surface @ the terminus* glacier surges- rapid movement and dramatic changes in size and form-due to hydrostatic pressure and hydroplaningGlaciation (the modification of the land surface by glaciers)-mass wasting and erosion haven't had time to cover up* erosion* transport* depositionGlacial Erosion and Sculpturea glacier acts as a plow, file, and sled:* plow- scrapes up weathered rock and soil, and plucks pieces of bedrock* file- rasps and polishes away firm rock* sled- carries away the load of sedimentlandforms of glaciated mountains (erosional):* cirques- bowl shaped depression open on one side, located on the side of a mountain (small lakes)* arete- shart crested ridge formed by the intersection of cirques* horn- sharp three-sided peak formed by the intersection of cirques* glacial valleys- "U" shaped cross section and main floor that lies below that of eroded tributary valleys* fjords- glacial valley on a coastline so that ...
