Earth Science Notes
Landforms
Landforms
Why do different landforms exist?
Earth Processes
• Weathering
• Erosion
• Forces within the Earth (plate movement)
• Climate
• Other?
Landforms
• Plains – large flat areas usually have thick
abundant soil ideal for farming
Landforms
• Interior plains –
found in the middle
of a continent
– Ex: Iowa, Nebraska,
the Dakotas
– Have a higher
elevation than
coastal plains
Landforms
• Coastal plains – found on the edge of the
continent
– Ex: Florida, Georgia, the Carolinas
– Formed as a result of collecting sediment on
the seafloor and dropping water levels.
Landforms
• Plateaus – flat raised areas of land made
up of nearly horizontals rocks that have
been lifted up by forces with in the earth.
– Ex: Colorado plateau
Landforms
Four Mountain Types
• Folded
• Upwarped
• Fault Block
• Volcanic
Mountains
• Folded Mountains – comprised of folded
rock layers like a rug that has been
pushed up against a wall.
– Forces occur on rock in a horizontal direction
– Ex: Appalachian mountains
• Believed to be at one time higher than the Rocky
Mountains but years of weathering and erosion
have worn the mountains down.
Folded Mountains
Mountains
• Upwarped Mountains – formed when the
forces within the earth push up blocks of
the earth’s crust. Soil is worn away and
the hard rock underneath is exposed.
– Ex: Adirondack mountains (New York), Black
Hills (South Dakota)
Unwarped Mountains
Forces with in the Earth
Mountains
• Fault-Block Mountains – made of huge,
tilted blocks of rock that are separated
from the surrounding rock by faults. Some
rocks move up some move down.
– Faults are fractures in rocks
– Ex: Grand Tetons (Wyoming)
Fault-Block Mountains
Mountains
• Volcanic Mountains – form from molten
rock that reaches the surface of the earth’s
crust through a crack or fissure. The
molten rock accumulates on top of itself
forming a cone shaped structure.
– Ex: Mount ST. Helens (Washington)
Volcanic Mountains
Landforms
How can topography aid us in describing
landforms?
Topography
Topographical Maps – show change in
elevation
Topography
Features on a
Topographical Map
• Contour lines – connect
equal points of elevation
• Contour intervals –
distance between contour
lines
• Index contours – contour
line with elevation
Topography
Reading a contour Map
• Close contour lines = steep change in
elevation
• Distant contour lines = gradual change in
elevation
Contour Lines
Contour Lines
Contour Lines
Contour Lines
Contour Lines
Contour Lines
Landforms
Summary
• Why do different landforms exist?
• Three types of landforms
– Plains – coastal / interior
– Plateaus
– Mountains – folded / upwarped / fault-block /
volcanic
• Topographical maps describe landforms