Glaciers & Climate Change. Kristen Tjostheim. Who, What, Why?. The audience: grade 8 challenge class, accustomed to fast paced lectures and group projects Basis of first third of lesson is from MT notes The topic: glaciers and icecaps Seen primarily as a source of freshwater
Glaciers also form high up in mountain ranges. Here the temperature is so cold that snow and ice melt very little. More and more snow and ice build up and begin to move. These glaciers, called valley glaciers, flow down through the high valleys between mountain peaks.
Although glaciers are always flowing downhill due to the force of gravity, they can appear to advance, retreat, or remain stationary based on the amount of snowfall and temperature.
Advancing Glacier – when it is colder, glacial build-up due to snowfall is greater than melting
Retreating Glacier – when it is warmer, melting is greater than the rate of build-up
Stationary Glacier – Rate of glacial build-up is equal to the melting
Due to their immense size and weight, glaciers can have a huge impact on the shape of the land through weathering, erosion and even deposition as they move over the land. As they melt, the moving water can shape of the land.
In the past, glaciers covered much larger areas of land during cold periods called ice ages (Earth's climate continually cycles through warm and cold periods). Sometimes glaciers are capable of picking up massive boulders from mountain ranges and moving them down onto the surrounding plains. When the glacier finally retreats during a warmer phase of Earth's climate cycles, these huge boulders called erratics get left behind in places like the prairies where they seem very out of place!
Describe at least four different ways that glaciers shape the land through erosion or deposition. Don't worry about what those landforms are called, just describe them.
How is this lesson imaginative?