Lesson 2:

Glacial Processes

What you should know by the end of this lesson:

The processes of glacial erosion
The processes of glacial deposition

Important!!

When explaining the formation of Glacial features you NEED to discuss the processes involved. This is a very easy way to pick up marks! As you get a mark for naming the process and a mark for explaining how the process works. You get credited for up to 2 glacial processes per feature.

For the erosional features, all of the processes are the same. Regardless of the erosional feature make sure you discuss Abrasion and Plucking!

For depositional processes, there is 1 extra but you may also get credit for an erosional process for some of the features.

Glacial erosional formations all follow a similar process when you describe their creation. You must describe how a glacier forms, then the processes and then the specifics of the features.

Digital Workbook and Paper Jotter

Take a note of each process and an explanation for it in your jotters
Draw a quick annotated diagram to show it in action

Processes of Erosion

Frost Shattering/Freeze-Thaw

Frost shatter weathering is when water in cracks in the rock freezes, expands and contracts to weaken the rock until fragments break off.

The broken-off rock fragments get absorbed by the glacier and carried away

Frost Shattering causes scree slopes to form today

Plucking

Plucking is when ice freezes onto bedrock, pulling loose rocks away from the ground.

Glaciers pluck and carry huge boulders then drop them when they no longer have the energy to continue. These are called erratic's.

Abrasion

Abrasion is when the angular rocks embedded in the ice (from plucking or freeze/thaw) grinds at the bedrock.

These scratch marks are called Striation marks and are left by the embedded rock inside glaciers Abrasion along the rock surface.

Processes of Deposition

Deposition

When the glacier moves far enough south or the temperature rises the ice loses power and can no longer carry rocks and boulders held within. It will then drop (or deposit) its load starting with the larger rocks and boulders first.