‘S‘S

VOCABULARY GLACIER - LARGE MOVING MASS OF ICE THAT FORMS NEAR EARTH’S POLES AND IN MOUNTAINOUS REGIONS AT HIGH ELEVATIONS. GLACIER - LARGE MOVING MASS OF ICE THAT FORMS NEAR EARTH’S POLES AND IN MOUNTAINOUS REGIONS AT HIGH ELEVATIONS.

MORAINE – RIDGE OF MIXED DEBRIS BEING DEPSITED BY A MELTING GLACIER. MORAINE – RIDGE OF MIXED DEBRIS BEING DEPSITED BY A MELTING GLACIER. This is what a moraine looks like

DRUMLIN – ELONGATED LANDFORM THAT RESULTS WHEN A GLACIER MOVES OVER AN OLD MORAINE. DRUMLIN – ELONGATED LANDFORM THAT RESULTS WHEN A GLACIER MOVES OVER AN OLD MORAINE. Drumlin (shows direction of glacier flow)

OUTWASH PLAIN – AREA AT THE LEADING EDGE OF A GLACIER, WHERE OUTWASH IS DEPOSITED BY MELTWATER STREAMS. OUTWASH PLAIN – AREA AT THE LEADING EDGE OF A GLACIER, WHERE OUTWASH IS DEPOSITED BY MELTWATER STREAMS. KETTLE LAKES – FORMED WHEN A LARGE BLOCK OF ICE BREAKS OFF AND FORMS A LAKE. (VERY COMMON IN NEW YORK STATE) KETTLE LAKES – FORMED WHEN A LARGE BLOCK OF ICE BREAKS OFF AND FORMS A LAKE. (VERY COMMON IN NEW YORK STATE) Outwash plain Kettle Lakes

TILL - material deposited directly by the glacier. (UNSORTED, unlayered). TILL - material deposited directly by the glacier. (UNSORTED, unlayered). FINGER LAKES – body of water that forms in a long narrow u-shaped glacial valley. FINGER LAKES – body of water that forms in a long narrow u-shaped glacial valley. till Notice how its unlayered and unsorted. Different sizes found throughout the sediment. (Big found on top and bottom

Glaciers Two types of glaciers: Two types of glaciers: 1. Valley glaciers (or alpine) – covers the floor of a valley. 1. Valley glaciers (or alpine) – covers the floor of a valley. 2. Continental glaciers (Ice Sheets)– covers continents and is thousands of meters thick. 2. Continental glaciers (Ice Sheets)– covers continents and is thousands of meters thick.

Valley (or Alpine) glacier

Continental Glaciers

Antartica

Birth of a Glacier As more and more snow falls and accumulates, the snow will compress and recrystallize into a rough, granular ice material called firn. As more and more snow falls and accumulates, the snow will compress and recrystallize into a rough, granular ice material called firn. The firn will grow and become solid ice. The firn will grow and become solid ice. The ice begins to flow. The ice begins to flow. This will then become a glacier. This will then become a glacier.

Snow turning into firn

Glacier Movement Glaciers move more rapidly in the center than the sides. Glaciers move more rapidly in the center than the sides.

Glacier movement VALLEY (ALPINE) GLACIER Notice the stakes. Glaciers move fastest in the middle. Why??

The rate of melting vs. movement may change and make the glacier appear to move backwards.

A typical advance and retreat of a glacier Notice the rock in the glacier. It’s always advancing down hill even though the glacier appears to be moving backwords

Glacier Movement If a glacier reaches a very steep slope, it will literally start to crack under pressure. If a glacier reaches a very steep slope, it will literally start to crack under pressure. These cracks are called crevasses. These cracks are called crevasses.

Glacial Erosion and Deposition Like running water, glaciers remove loose rock and carry them with them as they move and eventually deposit them. Like running water, glaciers remove loose rock and carry them with them as they move and eventually deposit them. However, unlike running water, due to their size, there is no limit to the size rock they can carry. However, unlike running water, due to their size, there is no limit to the size rock they can carry.

ALL SEDIMENT DEPOSITED BY A GLACIER IS UNSORTED AND UNLAYERED!!!!! ALL SEDIMENT DEPOSITED BY A GLACIER IS UNSORTED AND UNLAYERED!!!!! Glacial Erosion and Deposition

The Glacial Valley When a glacier has rocks in it, as it moves the rocks will scratch the valley floor and leave behind striations – a sure sign that a glacier was in the area is a rock with striations on it!! When a glacier has rocks in it, as it moves the rocks will scratch the valley floor and leave behind striations – a sure sign that a glacier was in the area is a rock with striations on it!! Also, the glacier can act like sandpaper and polish and smooth the valley floor. Also, the glacier can act like sandpaper and polish and smooth the valley floor.

Glacial Striations Glacial Polish

Glacial striations, left by flowing ice, British Columbia

Glacial erosion Formed by “plucking THIS IS HOW THEY DO IT

The Glacial Valley As the glacier moves through the valley and carves out the rock, it leaves behind a U- SHAPED valley!!!! As the glacier moves through the valley and carves out the rock, it leaves behind a U- SHAPED valley!!!!

The diagram to the left shows a mountainous landscape prior to glaciation. Notice the gently rounded mountains and the young, V-shaped valleys (formed by running water). This diagram depicts the same landscape covered by glaciers. Notice the many alpine glaciers feeding into a large valley glacier. Higher up, a few cirque glaciers are also present. The last diagram shows the post-glacial landscape. Notice the sculpting of the mountain peaks and the valley’s transformation from V-shaped to U- shaped.(U shaped formed by glacier)

Glacial Deposits 1. Till – unsorted, unlayered rock material deposited directly from the glacial ice. 1. Till – unsorted, unlayered rock material deposited directly from the glacial ice.

Moraines When glaciers deposit material they form moraines (piles of sediment and rocks). When glaciers deposit material they form moraines (piles of sediment and rocks). At the ice front, a lot of material gets deposited and the pile that builds-up there is an end moraine. At the ice front, a lot of material gets deposited and the pile that builds-up there is an end moraine. The very last end moraine marks the glaciers farthest advance and that is known as the terminal moriane. The very last end moraine marks the glaciers farthest advance and that is known as the terminal moriane.

Other Glacial Deposits Extremely large boulders that do not match the bedrock that they are found on are probably dropped by glaciers. These are called erratics. Extremely large boulders that do not match the bedrock that they are found on are probably dropped by glaciers. These are called erratics.

What would make you think a glacier deposited this? Rock Type does not match - area rock (All the rock around is igneous yet these big rocks are metamorphic The size of the rock – to big to be carried by running water

Other Glacial Deposits Long, smooth, canoe- shaped hills made of till are called drumlins. Long, smooth, canoe- shaped hills made of till are called drumlins. Drumlins are great for telling the direction the glacier moved, because they point in the direction it moved. Drumlins are great for telling the direction the glacier moved, because they point in the direction it moved.

Glacial Lakes Kettle lakes are circular hollows that fill in with meltwater from the glacier. Kettle lakes are circular hollows that fill in with meltwater from the glacier. Darien Lakes are kettle lakes!! Darien Lakes are kettle lakes!!

Esker Till Moraine- dammed lake Terminal Moraine Glacial Stream Outwash Plain Kettle Lakes Drumlins Kames Glacier Your copy did not turn our very well. If you need to add to your copy to have it make more sense please do so. Click the next arrow to make this disappear.

WRITE THESE DOWN EROSIONAL FEATURES EROSIONAL FEATURES How do you know a glacier has been here?? 1. U – SHAPED VALLEYS 2. PARALLEL SCRATCHES ON THE SURFACE OF ROCKS (STIATIONS) 3. ERRATICS - STUFF FOUND IN AREAS THAT IT DOESN’T BELONG (METAMORPHIC BOLDER IN A REGION OF IGNEOUS ROCKS 4. Drumlins- Show direction of Glacier Movement 5. Unlayered unsorted sediment