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Earth's Interior
Wild Card
Drifting Continents
Sea-Floor Spreading
Theory of Plate Tectonics
100
Heat transfer is the movement of energy (heat) from __________ objects to cooler objects. Name the 3 ways heat can be transferred.
WARMER. Radiation, convection, conduction
100
The theory that explains how and why continents moved.
Plate tectonics. The theory of plate tectonics explains the formation, movement, and subduction of Earth's plates.
100
What did Alfred Wegener hypothesize in regards to the relationship between the continents?
Wegener hypothesized that the continents had once been joined together forming a supercontinent and have since drifted apart.
100
Wegener's theory of continental drift was finally confirmed when Harry Hess discovered this process; the process continually adds new material to the ocean floor.
Sea-floor spreading
100
What layer of the Earth is broken into "plates"? These plates are in constant ______________?
Lithosphere. The litosphere is the is a very ________ layer of the Earth. These plates can include both oceanic and continental crust. Examples: ?? (see page 133). These plates are in constant MOTION.
200
What are the 3 MAIN layers of Earth's interior? Please answer from outer most layer to inner most layer. 2/3 of Earth's mass is found in the ___________.
Crust, mantle, core. 2/3 of Earth's mass is found in the mantle.
200
If you were to live in an area where frequent earthquakes occured, you may suspect that you are living near a _____________ ______________ boundary.
tectonic plate
200
The name of the supercontinent that existed over 225 million years ago. Name the two continents that were formed after the break up of Pangaea.
Pangaea. Gondwanaland and Laurasia.
200
Where is new crust created? Where is oceanic crust destroyed/recycled?
New crust is created along mid ocean ridges. Older, oceanic crust is destroyed (subducted) along deep ocean trenches where oceanic and continental crust collide; convergent plate boundaries.
200
The lithospheric plates "float" on top of the _______________? The flow that causes the movement of Earth's plates?
Asthenosphere, Convection currents
300
Continental crust is __________ dense than oceanic crust?
LESS
300
True or False: At the center of a mid-ocean ridge is a deep ocean trench.
FALSE! At the center of a mid-ocean ridge is a RIFT VALLEY. Deep ocean trenches are found near subduction zones or an oceanic/continental convergent plate boundary.
300
The idea that CONTINENTS have slowly moved over Earth's surface and have DRIFTED apart.
Continental Drift
300
True or False: Rock found along mid ocean ridges is younger than rock found away from the ridge. The crack in the ocean floor through which magma rises is a __________.
True. As molten lava rises from the mantle and erupts along the mid ocean ridge, it spreads out and pushes older rock out and away from the ridge. The crack in the ocean floor through which magma rises is a RIFT.
300
What happens to the crust at transform plate boundaries?
Two plates slide past each other. Crust is neither created nor destroyed.
400
The UPPER mantle plus the crust is known as this rigid layer of Earth.
Lithosphere
400
Heat transfer by movement of heated fluids is known as _______________?
Convection
400
Give 2 pieces of evidence that supports the theory that the continents were once all connected.
Plant fossils, Mesosaurus fossils, Mountain ranges, Glacial deposits, Coal beds
400
True or False: Oceanic crust farther from the mid ocean ridge is more dense than crust close to the mid ocean ridge.
True. As new, hot oceanic crust is formed, it eventually is pushed away from the mid ocean ridge, cools down, and becomes more dense.
400
The boundary where two plates move apart? An example of this type of boundary?
Divergent plate boundary. Mid-ocean ridge or a rift valley.
500
The solid but softer, plastic-like, portion of the mantle where we find convection currents moving the plates.
Asthenosphere.
500
1. Mass=6.2 grams Volume=25 cm3 Density=? 2. Mass=? Volume= 100 mL Density=1.5 g/mL 3. Mass=60 grams Volume=? Density=3 g/mL
1. Density=.23 g/cm3, 2. Mass=150 grams, 3. Volume=20 mL,
500
Why did other scientists reject Wegener's theory of continental drift?
Wegener's idea was just a theory, he could not explain exactly how the continents were moving.
500
List at least 2 ways scientists proved new crust was formed at mid ocean ridges.
Alvin found pillow shaped rocks that can only form when molten lava hardens quickly after erupting under water. Scientists have discovered that the rock that makes up the ocean floor lies in a pattern of magnetized "stripes" which show a pattern in the reversals of Earth's magnetic field. Rock samples were obtained by drilling into the ocean floor. The rocks near the mid ocean ridge were dated and found to be "younger" than the rock samples taken farther away from the mid ocean ridge.
500
A boundary where two plates come together? When two plates collide, which one subducts?
Convergent plate boundary. When two plates collide, the plate that is more dense is the plate that subducts. At a boundary where an oceanic plate collides with a continental plate, the more dense oceanic plate will subduct. At a boundary where 2 oceanic plates collide, the older, more dense plate will subduct. At a boundary where 2 continental plates collide, neither are dense enough to sink into the mantle. Instead the collision causes the crust to push together to form mountain ranges.