Transcript Earth`s Landforms

Earth’s Landforms
Chapter 1
Lesson 1
Where do Landforms come from?
• Plate tectonics
– Large, slow moving plates that
make up Earth’s surface. When
moved, they carry continents
and the ocean floors!
Where do Landforms come from?
• PANGAEA & Continental Drift
– SUPERCONTINENT! Continental drift theory is
the belief about what broke Pangaea up into the
seven continents.
Where do Landforms come from?
• Mountains:
– Formed when
plates push
together, crumble
and fold. Also when
plates push
together and one
moves over the
other.
• Ex. Himalayas,
Cascade Mts.
Where do Landforms come from?
• Earthquakes…..
– Caused by the
movement of
tectonic plates.
Most common
around fault
(break in Earth’s
surface where
movement can
occur).
• Ex. San Andreas
Fault
THINK ABOUT THIS……
• Two cars driving
VEEERRRRYYYYY
SLLLOOOWWW bump into
one another. Do the
passengers in the car feel the
bump?
• DUHHHH. Now multiply the
size of those cars by 100,000
(tectonic plates). Will the
bump feel larger or
smaller?????
Volcanoes
• FORM:
– When two plates push together and one goes
up and the other goes down. Lower plate
melts into magma.
• KINDS OF VOLCANOES
– Shield volcano, cinder-cone mountain
• SHAPED EARTH
– Add land when the lava cools and hardens
THINK ABOUT THIS……
• Water on the stove…
– Water gets hotter and
hotter (tectonic plate)
until it…….
BOILS!! (volcanic
eruption)
EARTH’S SURFACE
• Weathering
– Process of breaking up rocks into smaller
pieces called sediment.
• Wind and Water
– Two major forms of weathering
• Erosion:
– Process of moving sediment from one place to
another
• Deposition
– Process of dropping sediment into a new
location
– Deposits add to the floodplain (the land next
to a river)
People Shape the Land
• People use floodplains for farming
– Settle near water…..why?
• Reshape waterways
– Ex. Building dams, creating lakes
• Direct water into dry places
– Irrigation
How else do people affect the shape of the
land???
GROUP QUESTIONS
• HOW DO PLATE TECTONICS CHANGE THE
SHAPE OF THE LAND? (3 WAYS)
• HOW DOES WEATHERING AFFECT THE LAND?
• WHATS THE DIFFERENCE BETWEEN EROSION
AND DEPOSITION?
• HOW DO VOLCANOS CHANGE THE LAND
AROUND THEM?