Transcript Earth`s Surface & People

Chapter 1 - Lesson 1
Shaping Earth’s Surface/
People Change the Land
Chapter 1
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)