Earth's Layers
What is the most dense layer?
The Core
What is the name of the original supercontinent?
Pangea
Who discovered the theory of seafloor spreading?
Harry Hess
This theory states that Earth’s surface is made of rigid plates that float on molten rock and move with respect to each other.
Plate Tectonics
This is where the tectonic plates meet. There are three ways that two plates can move relative to one another.
Plate Boundaries
The San Andreas Fault in California is an example of this type of plate boundary, which is why so many earthquakes occur there.
Transform Boundary
Where do convection currents happen?
The Mantle
Who discovered the theory of continental drfit?
Alfred Wegener
What did the theory of seafloor spreading propose is moving the continents?
The ocean floor moves and carries the continents with it.
(I will also accept convection currents)
This mechanical layer is where tectonic plates subside. It is made out of the solid crust and upper mantle of Earth's interior.
Lithosphere
At this plate boundaries, tectonic plates slide by each other. Lithosphere is neither created nor destroyed.
Transform Boundary
The Mariana Trench was created due to this type of plate boundary.
Convergent Plate Boundary (subduction of a more dense oceanic plate under a less dense continental plate)
What are the mechanical layers separated by?
Behavior
Name the vocab word based on the definition:
An explanation for how or why something occurs in the natural world.
Scientific Theory
In the middle of the Atlantic, Pacific, and other oceans around the world was a chain of mountains and rift valleys. These are now known as:
Mid-Ocean Ridges
This super hot mechanical layer behaves as a plastic and flows super slowly, carrying the tectonic plates with it.
Asthenosphere
At this plate boundary, plates move away from each other. Magma comes up and fills in the gaps.
Divergent Boundary
When two oceanic plates collide, the older and denser plate subducts, creating a deep ocean trench and a line of volcanoes called an:
Island Arc
What are the compositional layers separated by?
Density
Name one piece of evidence that supports the theory of continental drift.
-The continents seem to fit together like a puzzle
-Fossils of animals were found on the coastlines of different continents
-There were nearly identical rock layers on continents that would have fit together
-plants that live in warmer climates were found to have fossils in Antarctica
What is happening on the ocean floor that is causing seafloor spreading?
Less dense basaltic magma erupts from beneath Earth’s crust and is pushed upward through the denser ocean floor. This new seafloor is then forced outward from the opening, spreading the seafloor apart.
Why does the generation of new crust not increase the size of Earth?
Older seafloor subducts under the continental crust, as new seafloor is created.
At this boundary, plates move toward each other and collide.
Convergent Boundary
Why do mountains continue to grow taller each day?
Two continental plates continue to converge/collide, always moving towards each other, causing more rock to uplift.
What is the only true liquid layer? (flowing iron)
The Outer Core
What was missing from Wegner's theory?
Wegner could not explain how or why the continents broke apart.
What new technology that came out in the 40s and 50s was used to create maps of the ocean floor?
Sounds Waves
What process heats up the asthenosphere, causing it to flow, and therefore causing the tectonic plates to move?
Convection Currents
At a convergent boundary, where one plate is more dense than the other, the more dense plate will sink under the less dense plate in a process called:
Subduction
Volcanoes are common in places where two plates collide that differ in:
Density