Glacial and Wave Erosion

• Define and describe the two main types of glaciers and how they form.

• Explain how glaciers shape the land through the processes of erosion and deposition.

• Identify key landforms created by both glaciers and waves.

• Describe how waves erode and deposit sediment to change a coastline.

Key Vocabulary

Glacier

A large, slow-moving mass of ice formed where more snow falls than melts over many years.

Continental Glacier

A vast glacier that covers a large island or continent, spreading out and flowing in all directions.

Valley Glacier

A long, narrow glacier moving downhill through a mountain valley, pulled by the force of gravity.

Plucking

An erosion process where ice breaks rocks, which then freeze to the bottom of the glacier.

Abrasion

The process where rock fragments dragged by a glacier or waves wear away the surrounding land.

Till

A jumbled mixture of different sized sediments that a glacier deposits directly onto the land's surface.

Key Vocabulary

Longshore Drift

Waves hitting the beach at an angle move sediment along the coast with the current.

Headland

A part of the shore that sticks out into the ocean, made of hard, resistant rock.

What Are Glaciers?

• A glacier is a large body of ice that moves slowly on land.

• ​They form when more snow falls than melts, compacting into solid ice.

• Continental glaciers are huge ice sheets covering large areas like Antarctica which move outwards due to weight.

• Valley glaciers are 'rivers of ice' that flow through mountain valleys due to gravity.

How Glaciers Shape the Land

• Glaciers erode land by plucking rocks and scraping the ground.

• As glaciers melt, they deposit a sediment mixture called till.

• This creates landforms like moraines, cirques, and U-shaped valleys.

How Waves Shape the Land

• Wind blowing across the water's surface creates most ocean waves.

• Impact is the force of waves hitting the shore, breaking rock.

• Abrasion is when waves use sediment to grind away the land.

• Waves focus their powerful energy on headlands that stick out.

Erosional Landforms

• ​Waves can carve out openings in steep, rocky coasts to create sea caves.

• ​​When erosion goes all the way through a headland, it can form a sea arch.

• ​If a sea arch collapses, a tall pillar of rock called a sea stack is left behind.

Depositional Landforms

• ​Waves also deposit sand and other sediment, which creates landforms like a beach.

• ​​The movement of sand along a beach, known as longshore drift, builds up the coastline.

• ​This process can create a spit or a sandbar, which are landforms made of sand.

• Glaciers erode by plucking and abrasion and deposit materials, constantly reshaping land.

• Glaciers create U-shaped valleys, horns, moraines, and kettle lakes.

• Wind-driven waves erode and deposit, continually changing coastlines.

• Wave action forms sea caves, arches, stacks, beaches, spits, and sandbars via longshore drift.