Glacial

Zone of ❌: colder, input > output

Zone of ❌: warmer, output > input, loss of snow and ice by melting and evaporation

brittle or rigid zone ❌, crevasses
plastic zone ❌, like melleable plastic

❌: A dome shaped sheet of ice that covers an area less than 50,000km2 in size

❌: has a topographically constrained sheet of ice in mountainous areas that frequently has glaciers streaming away from it.

❌: A glacier in mountainous regions that flows down preexisting valleys.

❌: blow shaped area, glacier is confined to the basin

❌: cirque spill over is river of ice confined with a valley, flows slowly down hill, landscape altered by its erosive passage

❌: if they flow down hill and come to the mouth of the valley and spread out over a flat land

❌: on a larger scale > 50,000 km2, continuous mass of unconfined ice is called a continental glacier, often as ice sheet in Greenland and Antarctica.

❌ – scratch and gouge bedrock by ice and rock debris it carries
❌ – caused by glacial abrasion
❌ – deep striations
❌ – boulders ripped from bed rock loosened by frost action

During the process of glacier erosion, ❌ occurs on the down-ice side of bedrock obstructions, ❌ on the up-ice side.

During the process of glacier erosion:

❌ – bowl-like feature on mtn flanks
❌ – small lake in bottom of cirque
❌ – narrow, steep ridges between cirques
❌ – mtn w/3 or more arêtes at summit
❌ – u-shape valley eroded by glacier
❌ – side trough above main trough – possible waterfall

The image shows a ❌

The image shows a glacial ❌

Forms of glacial till

❌ Till: deposited at the base of the glacier.Intense pressure.Fine grained.Crushed at the bottom.

❌ Till: sediment carried within or on top of ice.

Types of Moraines:

❌ – along former edges of glacier
❌ – along front of former glacier
❌ – formed as glacier recedes
❌ – between 2 glaciers
❌ – irregular deposition as glacier recedes

A - ❌ moraine
B - ❌ moraine
C - ❌ moraine
D - ❌ moraine
E - ❌ moraine

Glacial deposional landforms (outwash):

❌ - flat feature in front of former glacier (formed by glacial outwash
❌ – sediments deposited by water out & under a glacier as it melts
❌ – large mound deposited near glacier front
❌ – winding ridge formed from stream flowing in tunnel through ice under glacier
❌ – big ice block fallen off glacier front is buried by outwash, melts later forming lake

Permafrost:

❌ – poleward of -7ºC mean annual isotherm – all surfaces frozen exp under water – avg 400 m thick, up to 1000 m thick
❌ – poleward of -1ºC mean annual isotherm – thinner than continuous, esp. on south facing slopes

❌ – distinct zones of frozen water within the ground – variable amts of water
As these areas freeze & thaw, expand & contract, they cause physical weathering
❌ – water enters crack in active layer
❌ – surface bulges because of ice under pressure below
❌ – land broken into polygons as frost pushes coarser material to surface