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What is a valley glacier? |
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Smaller glaciers found in the mountains on overy continent except Australia. They carve U-shaped valleys into mountain ranges. |
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A giant piece of ice floating in the water that has broken off from an ice sheet. 90% of an icberg is underwater. |
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What is a continental glacier? |
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An enormously large and thick sheet of ice found only in Antarctica and Greenland that moves slowly outward from the center. Roughly circular or oval in shape. |
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The lowest level that permanent snow reaches in the summer on a mountain. |
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Where can glaciers exist/begin? |
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Glaciers can only exist in areas where there is more snowfall than melted snow every year. |
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A rough, granular ice material found in a glacier. |
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What is another name for a continetal glacier? |
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The exposed summit of a ridge, mountain, or peak not covered with ice or snow within a glacier. |
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Great cracks upto 40 m deep in a glacier. Ice is brittle up to this depth. |
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Point where ice melts as fast as it moves. |
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The process of huge chunks of ice breaking off an ice sheet to form icebergs. |
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Deposits of materials carried by a glacier. |
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What is a ground moraine? |
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Definition
Material carried in the bottom of a glacier before it is deposited. |
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What is a ground moraine? |
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Definition
Material carried in the bottom of a glacier before it is deposited. |
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What are lateral moraines? |
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Definition
Materials glaciers pick up from valley walls. |
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What are medial moraines? |
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Definition
Long winding lines in the middle of a glacier formed when two glaciers combine along with their lateral moraines. |
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Definition
Deposits formed when glicer reaches ice front and maltes, releasing materials. |
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A mixture of fine sand and silt formed by the crushing of rock under a glacier. |
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Water coming out of a glacier that is mixed with glacial flour. |
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How do glaciers erode rock? |
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Definition
Largely by using rocks as cutting tools. |
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Long parallel scratches left on bedrock from pebbles and gravel. Indicate direction of glacier. |
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A semicircular basin formed at the head of a glacial valley. Glaciers start here. |
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A sharp ridge in between two cirques. |
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What is a horn? Give an example. |
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Definition
A pyramid-shaped peak formed when three or more ciques cut into the same peak. Ex. The Matterhorn in Switzerland. |
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What is a glacial trough? |
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Definition
A glacial valley that is roughly U-shaped. |
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What is a hanging trough? |
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Definition
A tributary glacial valley. |
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What is a hanging trough waterfall? |
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Definition
A waterfall formed when rivers begin in hanging trough valleys. |
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How does the erosion from continental glaciers differ from the erosion from vally glaciers? |
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Definition
Continental glaciers round off and polish mountain peaks and ridges. Valley glaciers sharpen peaks by grinding away at their sides |
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Any deposit of glacial origin. |
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What are the two kinds of drift? |
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Definition
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UNSORTED and unstratifed rock material deposited directly by glacier. |
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Deposits made by glacial streams. Due to this, out wash is SORTED. |
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What is a terminal moraine? |
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Definition
The deposit from the glaciers farthest advance. |
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What causes an end moraine to grow larger? |
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Definition
If the ice does not advance for a long time. B/c the ice is still all moving forward along with the materials in it. |
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Definition
Long, smooth, canoe-shaped hills made of till. Usually found in swarms. Formed when a glacier ran over a preexisting moraine. |
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Gently sloping sorted deposits of out was that form from glacial streams. |
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Long winding ridges that are deposits from subglacial streams. |
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Small, cone-shaped hills of stratified sand and gravel. How are they formed? |
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Circular hollows found on terminal moraines and out wash plains. Formed when large blocks of ice are buried in terminal moraine and ice melts. |
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Formed when glacial streams empty into lakes. |
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What are two other names for a valley glacier? |
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Definition
Mountain glacier, alpine glacier. |
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What type of glacial period do we live in? |
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Definition
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How many times have glaciers gone over A2 in last 2 mil. years? |
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How do all glaciers move forward? |
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Definition
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How do valley glaciers move in warm climates? |
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Definition
By basal sliding (and internal deformation) |
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The entire glacier sliding down the slope lubricated by meltwater. |
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What is internal deformation? |
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Definition
Occurs when ice and ice crystals move over and around each other. |
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Do glaciers have a lot of force? |
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Definition
Yes, F=m*a and they have A LOT of mass. |
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Glaciers are a(n) __________ and a __________ force. |
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Definition
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Why might a glacial ice age start? |
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Definition
If all 3 of these happen at once: 1. Times in our orbit when we are a little farther away 2. Earth changes its axis every so often 3. Fo some reason we get less energy from the sun |
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How much does the planet have to go down for an ice age to start? |
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Definition
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What is the rule about what latitude and altitude glaciers must form at? |
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Definition
The greater the latitude, the less the altitude has to be and vice versa. |
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What are the different sections of a glacier? |
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Definition
The top 30-40 m are brittle (crevasses can form). The rest is called plastic. It is so dense that it is extremely hard(about a 5 on Mohs scale). |
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Glaciers can calve underwater. T/F? |
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