Glacial Erosion+transportation Flashcards

1
Q

What processes erode the valley floor?

A

Abrasion and plucking

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2
Q

What is plucking?

A

When the ice is in contact with the rock surface freezes around the rock and as the glacier moves forwards it plucks the rocks away from the valley

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3
Q

What is abrasion?

A

Debris carried along by the glacier that scrapes martial off the valley walls + floor

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4
Q

What occurs in meltwater erosion?

A

Glaciers produce large amounts of meltwater that make the streams powerful enough to erode the valley floor through erosion processes

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5
Q

What is weathering?

A

First shattering - breaks off the back and side walls of the valley
-meltwater freezes in cracks,expanding and breaking away at the rocks

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6
Q

What are the three main ways debris is transported in a glacier?

A

Supraglacial - material carrier in top of the glacier surface

Englacial - carried within the body of the glacier

Subglacial- moved along at the base of the glacier

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7
Q

What is the unsorted deposited material called?

A

Till ( or Boulder clay)

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8
Q

Where is ablation till and lodgement till deposited?

A

Lodgement - spread on the valley floor beneath the glacier

Ablation till - dropped by the glacier as it melts

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9
Q

what is freeze shattering/thaw?

A

when water fills the cracks and then freezes causing them to expand by 9%
this creates pressure on the rocks and eventually enlarging them
this process occurs over and over again and results in rock breaking up then appearing as scree

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10
Q

what is frost heave?

A

when the active layer begins to refreeze (periglacial) and ice crystals develop
this increases the volume of soil and causes upward expansion of the soil surface

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