Landscapes Shaped by Glaciation
Landscapes Shaped by Glaciation
Items in this lesson
Landscapes Shaped by Glaciation
What do you already know about glacial features and their origins?
Learning Objective
At the end of the lesson you will be able to describe key glacial features, explain how they form, and analyse the impact of glaciation on the landscape.
What is Glaciation?
Glaciation is the process by which glaciers shape the land. It involves erosion, transport, and deposition of material by moving ice.
Formation of Glaciers
Glaciers form in cold climates where more snow falls than melts. Over time, snow compacts into ice, which flows under its own weight.
U-Shaped Valleys
Glaciers carve deep, steep-sided U-shaped valleys from V-shaped river valleys by eroding the sides and floor as they move.
Cirques (Corries)
Cirques, or corries, are armchair-shaped hollows where glaciers begin. Ice erodes the back wall through plucking and abrasion.
Arêtes and Pyramidal Peaks
When two cirques erode back-to-back, a narrow ridge called an arête forms. Where three or more cirques meet, a pyramidal peak develops.
Moraines
Moraines are accumulations of rock and debris left behind by melting glaciers. Types include lateral, medial, and terminal moraines.
Erosional vs Depositional Features
Erosional
Depositional
Examples: Moraines, drumlins, erratics. These are formed when glaciers deposit material as they retreat.
Examples: U-shaped valleys, cirques, arêtes. These are formed as ice scrapes and removes material.
Questions for Deeper Learning
1. Describe the process that shapes a U-shaped valley. 2. Explain the difference between an arête and a moraine. 3. Predict how glacial landscapes might change over thousands of years.
Write down 3 things you learned in this lesson.
Write down 2 things you want to know more about.
Ask 1 question about something you haven't quite understood yet.
