Chapter 1 - Lesson 1 Shaping Earth’s Surface/ People Change the Land The World’s Geography

Shaping Earth’s Surface page 23 There are several ways that the Earth’s surface can change Weathering is a way the Earth’s surface is changed Weathering - is the process of breaking up rocks into smaller pieces called sediment

Shaping Earth’s Surface Water is an agent of weathering Moving water tumbles rocks against each other, breaking them into pieces In this way moving streams and rivers weather away land and produce canyons

Shaping Earth’s Surface Ocean waves weather away sea cliffs, turning them into beach sand or causing them to fall into the sea

Shaping Earth’s Surface Moving Ice in the form of glaciers can also change landforms Glaciers are thick sheets of ice formed in areas where more snow falls than melts As glaciers move, they grind the land below them, causing the land to “weather” away beneath them

Shaping Earth’s Surface Wind is another agent of weathering Strong, steady wind carrying sand can grind hard desert rock. Rainbow Bridge, Utah

Shaping Earth’s Surface After the weathering has broken socks into sediment, erosion and deposition move the sediment to new places. Erosion – the process of moving sediment Deposition – the process of dropping, or depositing sediment in a new location

Shaping Earth’s Surface Erosion and deposition make landforms bigger and produce new landforms Example: Rivers pick up sediment as they move downstream. Then the river floods and it deposits that sediment in flat areas along the river banks. These deposits add to the floodplain A river can also deposit sediment at its mouth creating a triangle-shaped piece of land called a delta Delta – a triangle shaped piece of land at the mouth of a river Floodplain – the land next to the river

Shaping Earth’s Surface Diagram of erosion (water)

Shaping Earth’s Surface Some examples of erosion

Shaping Earth’s Surface Diagram of deposition

Shaping Earth’s Surface Some examples of deposition

What physical processes shape landforms? (pg.24)

People Change the Land pg.25 Human activities also change the Earth’s surface The floodplains and deltas that weathering, erosion, and deposition create, humans use as farmland In Asia, people grow rice on the sides of mountains by cutting into the slopes forming flat fields along the side, this prevents erosion and keeps water on the field

People Change the Land

People Change the Land People build dams to control the flow of rivers and produce electricity Lakes are also created to store water People drain wetlands of their water in order to make dry land to build cities and farms. Humans also direct water into dry areas to make it possible to live in dry areas of the world

People Change the Land

Terms to Know Weathering Erosion Deposition Floodplain delta What are some ways in which people change the physical environment? (pg. 25)