Glacial Erosion

Glacial Erosion

By: Marielle Cuenca, Jessica Guerra, Alexis Hernaez, and Amanda Silva P.3

Vocabulary:

Vocabulary :

• Abrasion- the process when a glacier erodes the underlying bedrock through contact between the bedrock and rock fragments embedded in the base of the glacier.
• Fjord- a long, narrow inlet of the sea between cliffs or steeps.
• Zone of Accumulation- area above the firm line, where snowfall accumulates and exceeds the losses form ablation (melting), evaporations, sublimation.
• Load- the amount of sediments that a slopes, rivers, or streams carries.
• Crevasse- a deep crack in an ice sheet or glacier.
• Glacial Striation- scratches or gouges cut into bedrock by glacial abrasion.
• Glacial Polish- the smoothing of a bedrock surface as a result of abrasion.

• Glacial Erosion- the process by which water, ice, wind, or gravity moves weathered rock and soil.
• Ice Age- one time in the past when continental glaciers covered large parts of Earth's surface.
• Iceberg- When a continental glacier reaches the ocean, a large piece of the glacier may break off and float away.
• Valley Glaciers- long, narrow glaciers that forms when snow and ice build up high in a mountain valley.
• Continental Glacier- a glacier that covers much of a continent or large island.
• Plucking- the process when a glacier flows over a land and picks up rocks.

Plucking and Abrasion:

Notes:

• Glaciers are masses of ice. Glacial erosion is the movement of a glacier that changes the land beneath it.
• There are two types of glaciers. They are valley glaciers and continental glaciers.
• A valley glacier is a long, narrow glacier that forms when snow and ice build up high in a mountain valley. Valley glaciers are found on many high mountains.
• A continental glacier is a glacier that covers much of a continent or large island. Continental glaciers are much larger than valley glaciers.
• Glacial erosion is the process by which water, ice, wind, or gravity moves weathered rocks and soil.
• There are two processes the glaciers erode the land.They are plucking and abrasion.
• Plucking is when a glacier flows over land and picks up rock.
• Abrasion is when a glacier erodes the underlying bedrock through contact between the bedrock and rock fragments embedded in the base of the glacier.

Notes:

• Crevasses are deep cracks in an ice sheet or glacier.
• Crevasses' sizes often depend on the amount of liquid water present in the glacier.
• Transverse crevasse are most common type. They form in a zone of longitudinal extension where the principal stress are normal to the direction of glacier flow.
• A bergschrund is a crevasses that divides moving glacier ice below the bergschrund from the stagnant ice above it may extend to bedrock below
• A crevasse may be as deep as 45 meters, as wide as 20 meters, and can be up to several hundred meters long.
• Glacial striations are scratches or gouges cut into bedrock by glacial abrasion.
• Glacial polish is the smoothing of a bedrock surface as a result of abrasion.

• The ice age was a time in the past when continental glaciers covered large parts of the Earth's surface.
• The most recent ice age was almost 10,000 years ago. The last ice age left traces that it was there, it left glaciers.
• Louis Aggasiz was one of the first scientist to study the clues of the ice age. Louis Aggasiz proved that they were there by glaciers because they were made of a kind of rock that you don't find in that area, which is granite. Because of that, he proved that they were from somewhere else. Other proof that the ice age really existed is: polished bedrock, sand and gravel piles, big valleys, and rough mountain tops.
• Icebergs are created when the edge of a glacier moves into the ocean and breaks off in pieces.
• Iceberg ice is about 10% as strong as concrete. This doesn't seem hard, but it's a lot harder than the ice you make in your freezer.

Questions:

Notes:

1. What are the two types of glaciers?

2. What are the two processes that glaciers erode the land?

3. Who was one of the first scientists to study the clues of the ice age?

• Fjords are long, narrow inlets of the sea between cliffs or steeps.
• Fjords are located in a number of countries around the world, like Greenland, Norway,New Zealand, and other places.
• The zone of accumulation is the area above the firn line, where snowfall accumulates and exceeds the losses form ablation (melting), evaporations, sublimation.
• The formation of glaciers depend on the zone of accumulation and its snowfall.
• Load is the amount of sediment that a slopes river or stream carries.
• As glaciers melt their remaining load of rocks are distributed in several ways.

Answers:

1. What are the two types of glaciers?

The two types of glaciers are valley glaciers and continental glaciers.

2. What are the two processes of which glaciers erode the land?

The two processes of which glaciers erode the land are plucking and abrasion.

3. Who was one of the first scientists to study the clues of the ice age?

One of the first scientist to study the clues of the ice age was Louis Aggasiz.