Glaciers

Contrast alpine and continental glaciers.

-alpine: formed at the top of mountains, flow downhill, tend to be small, make topography more intense -continental: formed at the poles, flow towards the equator, huge, flatten topography

Evidence for glaciers?

-grooves (indents) -polished rocks -chatter rocks (divots)

Contrast river cut terrain with glacier cut terrain.

-river cut terrain: v-shaped valleys - glaciers cut terrain: u-shaped valleys, glaciers make valleys deeper (steep walls)

Contrast river deposits with glacial deposits.

-river deposits: rocks are sorted, rocks are generally rounder -glacial deposits: rocks are unsorted, rocks are more angular

Features of glacial deposits?

-unsorted rocks -rocks are angular -moraine

Contrast a drumlin with a kettle.

A drumlin is a hill (build up) and a kettle is an indentation. Both are depositional features.

Contrast a lateral moraine and an arete.

Both formed on the side; lateral moraine is a deposit formed by one glacier, an arete is the bedrock that was left behind by two parallel glaciers.

Why do glaciers move? How do glaciers move?

Glaciers move because there are many layers of a glacier, and once the solid ice has become compressed enough, it turns into a flowy solid. This flowy solid is called plastic flow, and causes basal slipping of the glacier. The water lubricates the glacier so that it can move.

Compare and contrast lateral moraines and eskers.

They are similar because they are both linear deposits. They are different because one is a glacial deposit and the other is a deposit from a river running through a glacier. Also, lateral moraine is straight, but the esker meanders.

drumlin

another pile of sediment under a glacier shaped like a drumstick

Describe how a cirque forms.

as the glacier flows downhill, it abrades the side of the mountain forming a bowl shape as it flows down

cirque

bowl at the top of the valley

plucking

cold water pressurized by glacier goes into the cracks of a rock, freezes, and the glacier flows over the rock and picks it up/ moves it

esker

deposit from a river that was flowing through the glacier

plastic flow

flowy solid formed when ice is under a lot of pressure

hanging valley

formed from a smaller glacier meeting a larger glacier

How do hanging valleys form?

formed when a smaller glacier meets a larger glacier

How did the great lakes form?

from extreme abrasion (from the glacier) which scoured out a divot

How did the finger lakes form?

from extreme abrasion which created giant grooves that filled up with water

Describe the processes that glaciers use to weather and erode.

frost heaving: Water gets into the cracks of rocks, freezes, expands, and cracks the rock. The rock is broken off of the mountain and the glacier pulls it away. When the rocks tear across the bottom of the valley because they are being tugged by the glacier, this causes abrasion: the rock rubs against/ destroys the bottom of the valley. plucking: Cold water pressurizes by glacier goes into the cracks of rock, freezes, and glacier flows over the rock and picks it up/ moves it. (pressure uphill, less pressure downhill)

glacial erratic

huge boulders deposited randomly by the glacier that tend to have no relation to the local rocks

continental glacier

huge glaciers formed at the poles that flow towards the equator (flatten topography)

glacier

ice moving under its own weight on land

firn

iceballs

angular

jagged-edged rocks

kettle lake

lake formed in the indentation from a leftover piece of ice (water flows around big ice, depositing sediment on either side creating mountains with lakes at the bottom)

tarn

lake in a cirque

lateral moraine

pile glacier left on its sides

ground moraine

pile glacier left underneath

medial moraine

pile of rocks between 2 glaciers

end moraine

pile of rocks in front of glaciers

arete

pile of rocks left behind by 2 parallel glaciers

outwash

river deposit from meltwater

abrasion

rocks tearing/rubbing against the bottom of the valley

moraine

rocks that were pushed by the glacier

rounded

rocks with smooth edges

alpine glaciers

smaller glaciers formed at the top of mountains that flow downhill (intensify topography)

basal slipping

the process of the glacier moving over its bed because of the meltwater lubricating the glacier

terminal moraine

very last end moraine

frost heaving

water gets into the cracks in rocks, freezes, expands, and cracks the rock/breaks them off the mountain: the rock gets attached to the glacier and the glacier pulls it away

polished

when a glacier smooths out the topography of a certain area

How do medial moraines form?

when two glaciers meet