Grade 5 - Chapter 3 Lesson 3 - Glacial Erosion

____________ shaped valleys indicate that an area was once covered by a glacier.

"U"

About 1 million years ago, continental glaciers covered how much of Earth's surface?

1/3

A Continental glacier flows in _________ directions.

All

High on mountain valleys, temperatures rarely rise above ____________________.

Freezing

By what processes do glaciers erode the land?

Glaciers erode the land by plucking and abrasion

Glacial lake

Glaciers may leave behind large lakes in a long basin

Snow builds up year after year. The weight of more and more snow compacts the snow at the bottom into ____________

Ice

In the past, continental glaciers have covered larger parts of Earth's surface known as?

Ice ages

Cirque

Is a bowl shaped hollow eroded by a glacier

Where can you find a kettle lake?

Wisconsin

A glacier picks up rocks through a process called ___

plucking

The process in which rock fragments freeze to the bottom of a glacier and then are carried away when the glacier moves is called ________.

plucking

The sediments deposited by a glacier are called ____________.

till

How many kinds of glaciers are there and what are they called?

2 Continental Glacier Valley Glacier

A glacier begins to move when the snow and ice build to which thickness?

30 to 40 meters

Although glaciers move slowly, they are a major force of ______________________

Erosion

Glaciers can form only in an area where more snow ________ than ___________.

Falls Melts

Kettle Lake

Forms when a depression left in a till by melting ice fills with water.

Moraine

Forms where a glacier deposits a mound or a ridge

The rock ______________ freeze to the bottom of the glacier.

Fragments

Which glacial features are caused by erosion?

Horns, criques, aretes, fiords, and U-shaped valleys

Drumlin

Is a long mound of till that is smoothed in the direction of the glacier's flow.

Arete

Is a sharp ridge separating two cirques

What is a terminal moraine?

Is the ridge of till at the farthest point reached by a glacier.

But a valley glacier that surges, or slides quickly can move as much as 6 _______________ in a year.

Kilometers

The movement of a glacier changes the __________ beneath it.

Land

When a glacier melts, it deposits the sediment it eroded from the land, creating various _________________,

Landforms

When a continental glacier is forming it looks like what?

Like pancake batter spreading out in a frying pan.

Part of ___________ ______________ in __________ ______________ is a terminal moraine from the continental glaciers of the last ice age.

Long Island New York

Valley glaciers flow at a rate of a few centimeters to a few ___________ per day.

Meters

Which glacial features are caused by deposition?

Moraines, drumlins, and kettle lakes (glacial lakes)

Can continental glaciers move in only 1 direction?

No the can flow in all directions as they move.

Where are valley glaciers found?

On many high mountains.

How far can a continental glacier spread?

Over millions of square kilometers

What is a till made up of?

Particles of many different sizes. Clay, silt, sand, gravel, and boulders can be found in a till

A glacier gathers a huge amount of __________ and ________ as it erodes the land in its path.

Rock Soil

Beneath a glacier, the weight of the ice can break ___________ apart.

Rocks

Are valley glaciers bigger or smaller than continental glaciers?

Smaller

How are the dense ice crystals on a glacier formed?

Snow is made up of microscopic crystals. As more snow falls, its weight turns some of the crystals underneath into water and vapor. The water and vapor refreeze which creates larger denser ice crystals.

Till

The mixture of sediments deposited directly by a glacier

Plucking

The process by which a glacier picks up rock as it flows over the land

How do glaciers form?

glacers form only in areas where more snow falls than melts. Snow build up, and its weight compacts the snow, forming ice that then begins to move downhill

A ________ is any large mass of ice that moves slowly over land.

glacier

A small depression called a ________ forms when a chunk of ice is left in glacial till.

kettle

A glacier deposits sediement when it _________.

melts

A glacier is any large mass of ice that moves _______ over land.

slowly

How big can valley glaciers become?

tens of kilometers long

How do glaciers move?

when the depths of a glacier reaches about 30 to 40 meters, the glacier begins to move downhill because of gravity. Continental glaciers flow in all directions.

Fiord

A fiord forms when the level of the sea rises, filling a valley once cut by a glacier

U Shaped Valley

A flowing glacier scoops out a U shaped valley

Continental Glacier

A glacier that covers much of a continent or large island

Valley Glacier

A long, narrow glacier that forms when snow and ice build up in a mountain valley

Moraine

A ridge formed by the till deposited at the edge of a glacier. A ridge, mound, or irregular mass of glacial drift, chiefly boulders, gravel, sand, and clay. a deposit of such material left on the ground by a glacier. ... A mass of till (boulders, pebbles, sand, and mud) deposited by a glacier, often in the form of a long ridge.

Kettle

A small depression that forms when a chunk of ice is left in glacial till.

How much of Earth's land is covered by continental glaciers?

About 10%

Many rocks remain at the bottom of the glacier and it drags them across the land which is called?

Abrasion Gouges and scratches the bedrock

Which land/area does a continental glacier cover?

Antarctica and Greenland

Glacier

Any large mass of ice that slowly moves over land

Plucking can move huge _______________.

Boulders

When a glacier moves, it ______________ rocks with it.

Carries

Where do valley glaciers spread on a mountain?

Down valleys that have already been cut by rivers.

What keeps valley glaciers from spreading in all directions?

The sides of the mountains

Did the glaciers advance or retreat?

They did both. Most recently they retreated about 10,000 years ago.

These landforms remain for _______________ of years after the glacier has melted.

Thousands

How do glaciers shape the landscape?

Through processes of plucking, abrasion, and deposition

Kettles often fill with _________________ forming small ________________ or lakes called kettle lakes.

Water Ponds

Horn

When glaciers care away the sides of a mountain, the result is a horn, a sharpened peak

When do glaciers deposit sediments?

When glaciers melt, they deposit sediment

Why are glaciers blue?

When sunlight hits the dense ice crystals absorb the red and yellow light. Only blue light escapes.

Glacier's gouge and scratch bedrock through the process of ___________.

abrasion

In a process called ______, the rocks dragged by glaciers produce grooces and scratches in the bedrock.

abrasion