| A | B |
|---|
| valley glacier | slow streams of ice that flows between steep rock walls from mountain tops |
| ice sheets | continental ice flows- huge ice mass that flows in all directions in extreme cold |
| Greenland | continental ice sheet |
| Antarctic | continental ice sheet |
| ice age | period of time that Earth was covered in glaciers |
| glacier | think ice mass 100's to 1000's of years old |
| snowline | lowest elevation in area remaining covered in snow all year |
| plastic | movement with 50m below the surfce due to pressure |
| basal | upper 50m is brittle - zone of fracture - gets a piggy back ride on plastic flow |
| budget | balance or lack of balance between accumulation at upper end and loss of ice at lower end |
| glacier erosion | by plucking and abrasion |
| plucking | picking up rocks and freezing them into the ice and carrying them downstream |
| abrasion | like sandpaper - smooth and polish rocks as the ice moves over them - produces rock flour that flows out with the meltwater |
| glaciated valley | V valley eroded to a U shaped glacial trough |
| hanging valley | a glacitaed valley cut off by another glacier resulting in a sharp drop and waterfalls |
| cirques | plucked rock in a bowl shape depression at the head of a glacial valley - 3 sides are steep rock walls |
| aretes | snaking, sharp-edged ridges |
| horns | sharp, pyramid-like peaks |
| glacial drift | eroded rock picked up by the glacier - 2 types |
| till | eroded rock deposited by glaciers when melting, unsorted and varies in size |
| stratified | eroded rock deposited by glaciers and laid down by meltwater - sorted by weight and size - usually sand and gravel |
| glacial erratics | boulders found free on the ground far from the original source |
| chemical weathering | organic acids, acid rain, rounded rock edges, some change in chemical structure |
| mechanical weathering | angular edges, sheer walls, surfaces covered in pebbles or sand, minerals unchanged due to lack of moisture |
| mechanical erosion | wind uses sand to blast rock and erode |
| ephemeral | streams only carry water after it rains |
| washes or arroyos | ephemeral streams |
| flash flood | no vegetation to stop or absorb water - results in severe erosion |
| basin | area between 2 lower mountain ranges |
| running water | creates most desert erosion |
| wind | transports and deposits the sediments that create sand dunes |
| humid areas | mostly water erosion and very little wind erosion |
| deflation | lifting and removal of loose particles, clay and silt |
| saltation | coarser sand particles that are skipped or rolled on the surface to erode |
| desert pavement | surface that is left after wind has removed finer particales of sand and silt |
| abrasion | wind blown sand cuts and polishes exposed rock surfaces |
| loess | windblown silt that blankets landscape |
| moraines | layers or ridges of till |
| lateral moraine | depositional feature that forms on the side of a valley glacier |
| medial moraine | depositional feature that forms from 2 valley glaciers meeting in the middle |
| end moraine | deposits rock debris at the end of the glacier and forms a ridge |
| ground moraine | glacier recedes and deposits debris over a rock-strewn plain |
| terminal moraine | farthest end moraine created after repeated stationary and receding |
| outwash plain moraine | meltwater chocked with sediments slows and drops dediments in broad ramp |
| kettles | block of stagnant ice becomes buried in drift and then melts, forming depressions in the land |
| drumlin | streamlined hills composed of till - steep side faces direction ice came from and gentle slope points in the direction ice moved |
| esker | snake-like ridges of sand and gravel deposits by glacial streams in tunnels beneath glaciers |
| Modern Ice Age | 2-3 million years ago - Pleistocene epoch - wooly mammoths and saber toothed sloth |
| last Ice Age | drainage and erosion created the Great Lakes, reshaped the Mississippi River, changed global climate, and dried up Lake Bonnevill, Utah and created the Bonneville Salt Flats |
| 6 types of sand dunes | barchan, transverse, barchanoid, longitudinal, parabolic and star |
