Glacier Basics

Glaciers

03

What happens to the rock

that is carved out of

landscapes by glaciers?

Glacier

Outwash Plain

Valley Glacier

Drumlin

Continental Glacier

Esker

Cirque

Kame

Moraine

Kettle

Vocabulary

Glacier

● A large mass of moving ice

● Form near Earth’s poles and in mountainous

areas at high elevations

● Cover ~10% of Earth’s surface

Moving Masses of Ice

The last continental ice age

● 30% coverage of Earth’s surface

● 2.6 million years ago

Moving Masses of Ice

Valley Glaciers

● Glaciers in valleys in high, mountainous areas

● As they flow downslope, they carve V-shaped

valleys into U-shaped valleys

Moving Masses of Ice

Continental Glaciers

● Cover broad, continent-sized areas

● Form in cold climates where snow

accumulates over many years

● Present Day – Greenland and Antarctica

Moving Masses of Ice

Valley glaciers and continental glaciers move
outward when snow gathers in the zone of
accumulation

● Where more snow falls than melts, evaporates,

or sublimates

Moving Masses of Ice

Valley glacier Zone – at the top of mountains
Continental glacier Zone – ice sheet center

● Both recede when melting is faster than

accumulation

Moving Masses of Ice

● Most powerful agent because of size and

weight

● As valley glaciers move, they break off pieces

of rock – plucking

● Glaciers embedded with rocks act as

sandpaper, grinding scratches into bedrock

Glacial Erosion

Cirques

● At high elevations where snow accumulates,

valley glaciers scoop out deep, bowl-shaped depressions

Glacial Erosion

Arête

● When two cirques on opposite sides of a

valley meet

Glacial Erosion

Horn

● A steep pyramid-shaped peak formed from

glacial carving on three or more sides of a mountaintop

Glacial Erosion

Hanging Valleys

● Formed by valley glaciers when higher

glaciers converge with lower glaciers then retreat

● Leaves a valley hanging high above the

primary valley floor

Glacial Erosion

Open Ended

Label each of the features of glacial erosion (A-E).

Glacial Till

● Unsorted rock, gravel, sand, and clay

embedded in the top, sides, and front edges
of glaciers

Glacial Deposition

Moraine

● Unsorted ridges of till deposited when a

glacier retreats

Glacial Deposition

Outwash

● The farthest ends of a glacier melts,

meltwater floods the valley below and the
gravel, sand, and fine silt sediment are
deposited by meltwater

Glacial Deposition

Outwash Plain

● Area at the leading edge of a glacier where

meltwater flows and deposits outwash

Glacial Deposition

Drumlins

● Continental glaciers moving over older

moraines form materials into elongated
landforms

Glacial Deposition

Eskers

● Streams flowing under melting glaciers

leaving long winding ridges of layered
sediment

Glacial Deposition

Kame

● A mound of layered sediment that forms

when till is washed into depressions or
openings in melting ice

Glacial Deposition

Kettles

● AKA kettle lakes

● Form when water from runoff or

precipitation fills a hole that formed when a
large block of ice breaks from a continental
glacier and melts

Glacial Deposition

Cirques can also fill with water and become cirque lakes

A terminal moraine can block off a valley, fill
with water and form a moraine-dammed lake

Glacial Deposition

● Continental glaciers carve out vast regions of

landscape leaving behind distinct features

Glacial Deposition

Open Ended

Label each of the depositional features (A-E).