Download 1 of 3 2.3 The Land NOTES - Pages 35

2.3 The Land NOTES - Pages 35-41
Learning Target: PG7 – I can recognize specific processes that operate on the Earth’s surface.(i.e. erosion, volcanoes,
earthquakes, wind and water currents, plate tectonics, and weathering)
Landforms
•Landforms are ____________________ on the planet’s surface
•Because they play an important ___________________ in geography, many scientists study how
they are made and how they __________________ human activity
Earth’s Plates
•Layers of the the Earth
–Inner & outer _______________ – inner is a solid ball of metals surrounded by outer core
which is molten metal
–______________________________ – is a liquid layer
–_______________ – solid outer layer (continents are part of crust
Plate Tectonics
•Theory geographers use to explain how forces below have __________________ our landforms
•Suggests that Earth’s surface is divided into about a dozens slow moving _____________
•Some plates are large, some are small, some are under the ______________, some are under
the _______________________- but they cover the entire Earth
•Energy deep inside the Earth puts pressure on the crust, as pressure builds it causes the
plates to _____________ or move
Continental Drift
•The theory that the Earth used to be ___________ big continent (Pangaea) but the plates
under the continents have shifted an ____________________the continent
•Plates are still ______________________– over time, colliding, separating, and sliding plates have
shaped Earth’s landforms
Plates Collide (Converge)
•The collision of different types plates creates different shapes on the Earth’s surface
•2 __________________ plates collide – one pushes under the other and ocean _________________
(deep valley in the ocean floor) is created
•Mariana Trench (near __________________) is the world’s deepest trench
•When ocean plate & ______________________________ plate collide – ocean plate drops beneath
the continental plate and crumples the land above forming ___________________ranges
•South American Andes Mountains is an example
•2 ______________________________ plates colliding also produces mountain ranges – land pushes
up to great heights
•Himalayas the world’s highest mountain range (29,000 ft above sea level)
Plates Separate (Diverge)
•As plates move _________________, gaps between the plates allow magma (liquid rock from
Earth’s interior) to rise to the crust
•__________________(magma that reaches the Earth’s surface) emerges from the gap
•As lava ______________ it builds mid-ocean ridges or under water mountains
•Can grow high enough to reach the surface & create _____________________ islands
•Largest is the Mid-Atlantic Ridge
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Plates Slide
•As plates pass by one another, they sometimes ____________________ together
•This grinding produces ________________________(sudden, violent movements of the Earth’s
crust)
•Earthquakes take place along _________________(breaks in the Earth’s crust where movement
occurs)
•San Andreas Fault located in _____________________________ is where the Pacific plate and the
North American plate meets
Ring of Fire
•Region that circles the _____________________Ocean plate
•Know for fiery ____________________________ & powerful ____________________________
•Stretches from the tip of South America all the way up to Alaska, and from Japan down to
the islands east of Australia
Mount Saint Helens in Washington State
•One of the best know volcano in the Ring of Fire
•Dormant since 1857 then erupted in May _________________
•Ash clouds 15ft high for 9 hrs – ______________ blanketed towns 200 miles away - ash
reached eastern US in 3 day – enter jet stream circled Earth in 2 wks
•Heat melted snow and created deadly __________________________
Weathering
•The process by which ________________ is broken down into smaller pieces
•Several factors cause rock to break down:
–Daytime ___________________ & nighttime ______________________– desert areas
–__________________water in cracks of rocks – ice expands and breaks them apart
•Small pieces of rock is known as ____________________________
•Sediment is moved from place to place by ___________________, _________________, and
______________________
Erosion
•Is the movement of ____________________________ from one location to another
•It can wear _______________________ or ___________________ up landforms
•_____________________ of erosion are wind, ice, and water
Wind
•Lifts sediment into the _______________ and carries it across great distances
•Blowing __________________ can wear down rock – acts like sandpaper to polish away rock
Glaciers
•Large slow-moving ____________________of ice
•Flow slowly downhill like rivers of ice eroding the land by carving large U-shaped
_______________________& sharp mountain ________________
•_______________________ rock into sediment
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Water
•Most _________________ cause of erosion
•Ocean waves _______________ away shoreline creating jagged coastlines
•Over many years rivers _______________through rock forming canyons
•Water can also __________________ landforms
•Rivers carry sediment
•Flooding rivers create _______________________ by depositing sediment along the banks
•Rivers carry sediment to the sea creating _____________where the river and sea meet
Landforms Influence Life
•Landforms influence where people ________________________
•Sometimes people settle ___________ certain landforms – flood plains & deltas have fertile
soil – rivers make transportation of good easier
•Sometimes landforms ________________________ settlement – rugged tall mountains like the
Himalayas, or deserts with little water
•Landforms affect __________________
•Rich mineral deposits in Colorado led to mining industry (__________)
•Landforms affect things like ________________________– large mountain ranges on the island of
New Guinea keep people isolated & there are more than 700 languages on the island
Changing landforms
•People sometimes change landforms to suit their ____________________
• Building of the Panama Canal made travel from the Atlantic to the Pacific easier
•Cut _________________ into step hillsides to grow crops
•Build _______________to divert water to nearby farms or create electricity
Show What You Know
•1. What is the difference between weathering and erosion?
•2. The earliest urban civilization was built between the Tigris and Euphrates rivers in the
Middle East. How did the location help the civilization thrive?
•3. What are some landforms in our area and how do they influence our lives?
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