What is the Theory of Pangaea?
All continents were once a single supercontinent
Fossils of the same extinct animals have been found on multiple continents, indicating they were once connected.
Name the continents that were part of Pangaea.
- North America
- South America
- Antarctica
- Europe
- Asia
- Africa
- Australia
These continents are still moving apart today.
Who developed the Continental Drift theory, and in what year?
Alfred Wegener in 1912
This theory states that continents have been moving apart at a rate of 1-2 centimeters per year.
What is Catastrophic Plate Tectonics?
A theory that a large catastrophe broke up Pangaea, causing immediate separation
This theory helps explain some ocean-floor geography.
List the four main layers of the Earth from outermost to innermost.
- Crust
- Mantle
- Outer Core
- Inner Core
Each layer has distinct properties and compositions.
What is the Crust of the Earth composed of?
Thin layer made of rock, composing continents and ocean floor
Includes both continental crust and oceanic crust.
Describe the Mantle of the Earth.
VERY thick layer, mostly solid rock that can heat up and flow slowly
Extends 1,800 miles down.
What is the temperature of the Outer Core?
7,200 ˚F
Composed of liquid iron and nickel, it creates the Earth’s magnetic field.
What is the temperature of the Inner Core?
10,300 ˚F
Composed of solid iron and nickel due to pressure from the layers above.
The crust is broken up into tectonic plates that are . . . ?
7 giant slabs of rock, moving slowly in constant motion
What causes the motion of tectonic plates?
Convection currents in the mantle
Hot material rises, cools, and sinks, creating circular motion.
What is a Divergent Boundary?
Tectonic plates move apart from each other, forming new oceanic crust
Magma rises to fill the gap.
What happens at a Convergent Boundary?
Tectonic plates move towards each other, leading to subduction
This process can create mountains.
Define Subduction
When plates slide beneath each other and creates mountains.
What is a Transform Boundary?
Plates slide alongside each other horizontally
This creates friction and can lead to earthquakes. Ex. San Andreas Fault in California
Define a Volcano.
An opening or vent or rift (under the ocean) in the earth’s surface that allows magma to escape the mantle
Magma is molten rock in the mantle, and lava is magma that reaches the crust.
Define Magma
Molten (liquid) rock in the mantle.
Define Lava
Magma that reaches the crust
How do volcanoes form?
- Along convergent boundaries 1 plate subducts beneath the other (subduction) leaving a vent for magma to rise
- Along divergent boundaries 2 plates separate (rift) leaving a rift in the ocean floor that magma fills
Magma rises through vents created by plate movements.
How was Hawaii Formed
A weak spot in the middle of a plate allowed magma to rise steadily above sea level.
What is an Earthquake?
A sudden shaking of the crust along a fault line
Caused by the release of potential energy stored between two plates released when they slip past each other.
What are fault lines?
Fractures in the crust where earthquakes often occur
Most commonly along convergent and transform boundaries.
Define Slip-strike Fault
Two plates slide past each other (transform)
Define Reverse Fault
Caused by compression of two plates against each other (convergent)
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Unit 1 Matter Able to Describe Questions8
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Unit 1 MATTER Definitions41
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Unit 2 Energy46
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Unit 2 Able to Describe14
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Unit 3 Earth Sciences26
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Unit 3 Able to Describe9
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Unit 4 Astronomy48
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Unit 5 Cardiovascular System17
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Unit 4 Able to Describe20
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Unit 5 Chapter 3 Blood53
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Unit 5 Able to Describe13
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Unit 5 Definitions24
