Earth's layers
The thin outer layer of rock above the mantle, including all dry land and ocean basins.
What is the crust?
This was the first person to study whether the continents had once been joined.
Who was Alfred Wegener?
The theory that states Earth's lithosphere is made up of huge plates that move over Earth's surface.
What is Plate Tectonics?
This is 160-180 million years old.
What is the ocean floor?
This is why the inner core is solid.
What is immense pressure?
The solid sphere of metal, mainly nickel and iron, at Earth's center.
What is the Inner Core?
The theory that continents were once joined and moved apart.
What is Continental Drift?
Most major earthquakes, volcanoes, and mountain ranges appear where these meet.
What are tectonic plates?
This is 4 billion years old.
What is the continental crust?
This part of the mantle is composed of hot, soft rocks that are close to melting.
What is the asthenosphere?
The layer of molten metal, mainly nickel and iron, that surrounds the Earth's inner core.
What is the Outer Core?
The name given to Wegener's super continent.
What is Pangaea?
These can move together, push apart, and scrape past each other.
What are tectonic plates?
These are huge underwater mountain ranges.
What are Mid-Ocean Ridges?
This is how far the rock in the mantle moves in a year.
What is a few centimeters?
The layer of rock between the Earth's outer core and crust and can flow in convection currents.
What is the mantle?
The two areas that the super continent broke into.
What are Laurasia and Gondwanaland?
This is the name for what happens when gravity pulls the edge of a dense plate into the asthenosphere.
What is a Slab Pull?
This occurs when molten rock rises through cracks in the ocean floor, cools and produces new crust that pushes old crust out of the way.
What is seafloor spreading?
This is the state of matter in the outer core.
What is liquid?
The layer of Earth composed on the crust and rigid rock of the upper mantle that is broken into tectonic plates.
What is the lithosphere?
The three things Wegener used to support the his theory.
What are: fossils; climate; and geology? Fossils that were found in Africa matching those found in South America; Climate - in South Africa's warm climate there's evidence of scratches on rocks from ice sheets; Geology - rocks on the eastern side of South America match those on the western side of Africa.
This is the name for what happens when material from a mid-ocean slides downhill from the ridge and pushes the rest of the plate.
What is a ridge push?
Earth stays the same size because old oceanic crust sinks into the asthenosphere through WHAT on the ocean floor?
What are ocean trenches?
These are Earth's three layers.
What are the core, mantle and crust.