Plucking (glaciation)

High school (ages 12+)
Geography

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/plucking-glaciation

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the primary mechanism?Freeze-thaw cycles of meltwater within bedrock joints, leading to hydraulic wedging
2. What is plucking in glaciers?Plucking is when ice pulls rocks off the ground by freezing water inside cracks, then the ice moves and takes the broken rock away.
3. How does meltwater help plucking?Meltwater seeps into cracks, freezes and expands, pushing the rock apart. When the ice moves, the rock can be pulled out.

Hydraulic Wedging: The process where water freezing in cracks expands, widening the cracks and fracturing rock.
Regelation: The process of melting and refreezing of ice due to pressure changes, aiding glacial movement.
Chatter Marks: Wedge-shaped or crescentic fractures left on bedrock by the impact of moving glacial debris.