Glaciers review

Glacier

Slow moving river of large ice, perennial, on land and next to land

Alpine glaciers

Glaciers in walled basins of valleys or mountains

Piedmont glacier

Glacier over lower lands at the base of a mountain

Valley glacier

Outlet glaciers that provide drainage for ice features and are generally confined to a valley

Accumulation zone

upper portion where snow falls and collects

Ablation zone

Lower portion of a glacier, ice losses occur here

Crevasses

Vertical crack in glacier

Cirques

Beginning point of alpine glaciers, location of glacial landform change

Arêtes

Ridge of rock that separates two valleys created by glacial erosion

Horn

peak formed as several criques gouge a mountain

Hanging valley

Basins carved by tributary glaciers high above the main valley floor

Tarns

Mountain lakes formed in cirques

Fjord

Drowned glaciated valley along the coast

Roche moutonneé

Asymmetrical hill of exposed bedrock

Till

unsorted glacial drift

Outwash

Sediments caught in meltwater and sorted

Moraines

Unstratified till dropped at the margins or ends of glaciers

Eskers

Curving ridge of course gravel along a meltwater channel

Kettles

Hole that fills as a lake and is created by glacial retreat

Kames

Small hill of somewhat sorted sand and gravel created in crevasses/surface indentations

Drumlins

Deposition hill formed by the streamlined movement of glacial ice sheets across till

Patterned ground

Freeze/thaw weathering that sorts rocks and soil into separate areas

Continuous permafrost

Consistent permafrost region

Discontinuous permafrost

Permafrost that is broken and sporatic

Pluvial periods

When lakes increase in size

Interpluvial periods

Associated with less moisture content, some lakes dry up

Ice age

Cold climactic condition with significant glacial expansion

Gelifluction

When the upper layer of regolith flows/creeps downslope

How freeze/thaw of permafrost impacts human settlements

Infrastructure (like powerlines and rails) twist and buildings subside

Arctic

10 degree C isotherm in July

Moulin

Vertical shat where meltstream reveals a weakness in ice

Eutrophication

Enrichment of water bodies with nutrients; creates dead zones