Glacial Erosion

Definition of a GlacierDefinition of a Glacier

A glacier is a large mass of ice that moves A glacier is a large mass of ice that moves slowly over land (a river of ice).slowly over land (a river of ice).

Nifty Glacier FactsNifty Glacier Facts

Glaciers grow and recede as the climate Glaciers grow and recede as the climate changes.changes.

Glaciers cover 10% of all land area.Glaciers cover 10% of all land area. Glaciers hold 75% of the world’s freshwater.Glaciers hold 75% of the world’s freshwater. The Antarctic Ice Sheet is over 40 million years The Antarctic Ice Sheet is over 40 million years

old.old. Glaciers can be found on nearly every Glaciers can be found on nearly every

continent.continent.

Types of GlaciersTypes of Glaciers

Two types of glaciers:Two types of glaciers: continental glaciers cover much of a continental glaciers cover much of a

continent.continent. valley glaciers form in a mountain range valley glaciers form in a mountain range

and are often long and narrow.and are often long and narrow.

ContinentalContinental ValleyValley

Formation of GlaciersFormation of Glaciers

Glaciers form in areas where more snow Glaciers form in areas where more snow falls than melts. falls than melts.

Once the glacier gets heavy enough, Once the glacier gets heavy enough, gravity causes it to flow downslope.gravity causes it to flow downslope.

Types of Glacial ErosionTypes of Glacial Erosion

U-shaped valleyU-shaped valley MoraineMoraine StriationsStriations Glacial lakeGlacial lake

U-Shaped ValleyU-Shaped Valley

A glacier is so heavy A glacier is so heavy that it scours out a that it scours out a path through the path through the landscape as it landscape as it moves.moves.

MoraineMoraine

A moraine is a deposit of glacial till that is left A moraine is a deposit of glacial till that is left behind after the glacier recedes. behind after the glacier recedes.

StriationsStriations

Striations are Striations are grooves cut in the grooves cut in the rock as a glacier rock as a glacier carves its way carves its way through an area. through an area. Striations provide a Striations provide a major clue that major clue that glaciers were in an glaciers were in an areaarea

Glacial LakesGlacial Lakes

A glacial lake is an A glacial lake is an old basin that has old basin that has been carved by a been carved by a glacier that is now glacier that is now filled with water.filled with water.

Other Notable Glacial Other Notable Glacial Facts:Facts:

Other notable Other notable features include;features include; IcebergsIcebergs Hanging ValleysHanging Valleys Great LakesGreat Lakes Ice cavesIce caves

IcebergsIcebergs

Icebergs are chunks Icebergs are chunks of glaciers that have of glaciers that have fallen off the main fallen off the main glacier into the glacier into the ocean.ocean.

““Calving” is the term Calving” is the term for an iceberg for an iceberg breaking off a breaking off a glacier.glacier.

Only 10% of an iceberg is visible above water.

Hanging ValleyHanging Valley

Ice CavesIce Caves

Ice AgesIce Ages

The last great Ice Age began about 70,000 years ago and ended about 10,000 years ago.

97% of what is now Canada and much of what is now the U.S. was covered with glacial ice.

Glaciers and the Ohio Glaciers and the Ohio RiverRiver

The Teays River system existed before The Teays River system existed before the glaciation of the ice age. the glaciation of the ice age.

The glaciers carved away the Teays and The glaciers carved away the Teays and left a large lake that eventually drained, left a large lake that eventually drained, ultimately creating the Ohio River ultimately creating the Ohio River drainage basindrainage basin

The Great Lakes were The Great Lakes were made from receding made from receding glaciers. The glacial glaciers. The glacial melt-water filled in the melt-water filled in the basins created by the basins created by the weight of the ice.weight of the ice.

The basins are now The basins are now gradually uplifting.gradually uplifting.

The Great Lakes hold The Great Lakes hold 20% of drinkable water 20% of drinkable water on Earth.on Earth.

Fun with Glaciers!Fun with Glaciers!

Glacier National Park