Earth's Structure Flashcards
Which of Earth’s layers is #1 and what is it made of?
Crust, upper “icing layer” of light rock
Which of Earth’s layers is #2 and what is it made of?
Mantle, made of heavy dry rock, softened by the core’s heat. (solid rock but hot and squishy)
Which of Earth’s layers is #3 and what is it made of?
Liquid Outer Core, still molten and moving around.
Which of Earth’s layers is #4 and what is it made of?
Solid Inner Core, condensed by very high pressure
Solid rock, slowly conducting heat
Lower Mantle
Squishy rock, slowly convecting heat
Upper Mantle
Earthquake waves tell us the core is made of ____ (___ and ___)
Metal (iron and nickel)
Where is Earth’s heat stored?
Core
How does the mantle move?
It circulates like boiling water but much slower. This carries heat from the core to the surface.
Earth’s strong outer rock shell (includes crust)
Lithosphere
Weak molten layer of rock beneath the lithosphere (Earths lubricating layer)
Asthenosphere
Since the Earths surface is broken into curved pieces, these _____ float around on the slippery asthenosphere
Plates
Why do lithospheric plates move?
To release heat
What is the earth’s main cooling mechanism?
Plate motion opens cracks (mostly in the ocean) for the molten mantle to erupt through
Oceans + Continents = ?
Plates
What’s the difference between the OCEANIC and CONTINENTAL lithosphere
Oceanic is thin and Continental is thick
Most plates contain a mix of ____ and ____
Oceanic and Continental lithosphere
What happens to the lithosphere on the ocean’s floor as the Earth moves?
New Ocean floor forms at the cracks. It spreads apart as it cools off, then gets dragged back into the mantle to melt
What happens to the lithosphere of continents as the Earth moves?
Continents can get pushed around by moving ocean plates, but they never get dragged back down in the mantle.
