Glaciers (Geology Final)

What are the two main types of Glaciers?

Valley (alpine) and continental

What is the accumulation zone?

Area where snowfall adds to the glacier

what is the ablation zone

area where ice melts or sublimates

what is a moraine

pile of debris deposited by a glacier

what is an end moraine

rdige marking the glacier’s furthest advance

What is an outwash plain

flat area formed by meltwater deposits

what is a crevasse

crack in glacier ice

how do glaciers move

internal flow and basal sliding

What are two main types of glacial erosion

plucking and abrasion

what landforms are created by valley glaciers

U-shaped valleys, cirques, arêtes, horns

what landforms are created by continental glaciers

drumlins, eskers, kettles, moraines

What are Milankovitch cycles?

changes in Earth’s orbit affecting climate

Name the three Milankovitch variables

eccentricity, tilt (obliquity), precession

how were the Great Lakes formed

glacial erosion and melting

What is glacial budget?

the balance between accumulation and ablation

What happens if accumulation > ablation

glacier advances

what happens if ablation > acuumulation?

glacier retreats

what is basal sliding?

glacier slides over bedrock due to meltwater

What is internal flow?

ice deforms and flows within the glacier

what is till?

unsorted sediment deposited directly by ice

what is stratified drift

sorted sediment deposited by meltwater

what is cirque

bowl-shaped depression where a glacier forms

what is an artête

sharp ridge between two glaciers

what is a horn

pointed peak formed by multiple glaciers

what is a drumlin

streamlined hill formed by ice movement

what is an esker?

ridge formed by sediment in sublgacial streams

what is a kettle?

depression formed by melting ice blocks

What is eccentricity

shape of earth’s orbit

what is obliquity (tilt)

angle of Earth’s axis

What is precession?

Wobble of Earth’s axis

How do glaciers affect sea level

growing glaciers lower sea level; melting glaciers raise it

does a tretreating glacier mean ice is moving backward?

no- ice stil moves forward, but melting exceeds accumulation