Glacial Landscapes

Crevasse • Deep open cracks in glacial ice

Headwall – Steep cliff that forms at the head of the glacier

Cirque – Semi-circular depression carved out by a glacier

• Small mountain lake perched on within a cirque that is dammed up by a moraine

Tarn

Tarn Formation

Glacial Scouring – Scrape marks left by the movement of the glacier

Glacial scrape marks on a boulder – all soil removed

Cirque

Headwall

Tarns

Moraine

Arete and Horns

Arete- A long ridge formed by ice scraping on two sides

Horn- A high peak carved by glaciers on all sides

U-Shaped ValleyValley glaciers carve out the bottom of valleys

into a smooth U-shape.

Fjord- a long, narrow, deep inlet of the sea between high cliffs

Hanging Valley

• When a valley glacier cuts a cliff off of an adjacent valley, resulting in a waterfall.

U-shaped valley

Waterfall dropping off the hanging valley

Glacial Moraine• A debris pile formed by ice as it plucks rocks from the

surface, transports it, and moves it to the edges.

Types of Moraines

• Terminal moraines form at the end or toe of the glacier

• Lateral moraines form along the edges

• Medial moraines form at the junction of two glaciers

Lateral Moraine

Tarn

Can You Spot the Cirques, Tarns, and Moraines in the Olympic Mountains?

Pro-glacial Lake

• Forms from meltwater at the toe of a glacier or from a glacial dam blocking a river.

Kettle Lakes

• Formed when pieces of glacial ice, embedded in glacial debris, melt, creating a hole that fills with water.

A Kettle Lake in Massachusetts

Drumlins

• Linear hills formed by the advancement and retreat of glaciers.

Seattle’s Hills Are Drumlins

• Green Lake is a Kettle Lake

Green Lake in Seattle is a Kettle Lake

Queen Anne HillCapitol Hill