Earths Layers Flashcards
(28 cards)
Which layer is molten material?
Mantle
Which layer of the core is solid?
Inner core
Which crustal layer is the least dense?
Continental crust
Which layer is liquid?
Outer core
What two minerals make up the core?
Iron and nickel
Who discovered continental drift?
Alfred Wegner
What is continental drift?
The movement of earths continents over time
Pieces of evidence to explain continental drift
- Shapes of continents
- Plant fossils
- Rock types
Why did other scientist reject continental drift?
They didn’t know how the continents moved
What is sea floor spreading
Sea floor spreading is when new oceanic crust forms from mid-ocean ridge
Prices of evidence that the sea floor is spreading
- Pillow lava rocks
- Age of sea floor
- Magnetic reversals
- Rocks on ocean floor thicker farther from ridge
Explain why the earth isn’t getting larger because of seafloor spreading?
Seafloor sub ducts back into the mantle
What in the earths mantle is responsible for seafloor spreading?
Convection currents
What direction do divergent boundaries move?
Away from each other
What landform is created at a oceanic oceanic divergent plate?
Mid-ocean ridge
Where is the divergent boundary found?
Atlantic Ocean
Landform from continental continental divergent plate
A Rift Valley
Where can divergent continental boundrys be found?
The great Rift Valley in Africa
What direction to transform boundrys move?
They slide past each other
What natural disaster takes place at transform boundaries?
Earthquakes
Where Can transform boundaries be found?
San Andreas in California
What direction do convergent plates move?
Towards each other
What landform is formed when two oceanic plates converge?
Subduction zone
Where are convergent boundaries found?
The Mariana Trench
