How long does weathering take?
It can take millions of years
Moving water can break down
rocks
When water freezes in a crack,
it widens the crack and breaks the rock apart
What can also make rocks crack?
Roots of a plant or tree that gets into a crack
Moving water and wind cause
erosion
What else can cause erosion?
Glaciers. The large piece of ice moves slowly across land and tears the rocks out of the ground.
What is a glacier?
a large piece of ice that moves across the land
How can people change the land?
When a pond is drained,
dry soil is left and it can blow away