Pangaea
When the continents all formed a single landmass and supercontinent.
Continental Drift
The hypothesis that today’s continents were once part of a single landmass.
What Evidence supported Alfred Wegener’s theory about a Continental Drift?
Rocks and fossils: Rocks and fossils found of the same species on continents separate sides of the Atlantic Ocean
The shape of the continents: Locations of mountain ranges and rock formations suggest the continent were once connected
Climatic Evidence: Locations of coal deposits and past glacial activity
Mid-ocean ridge
A long, undersea mountain chain that forms along the floor of the ocean
Where do mid-ocean ridges occur?
Along Divergent plate boundaries
Sea-floor spreading
The process by which new sea-floor is formed
Tectonic Plates
Are pieces of what the lithosphere is made up of and move around on top of the asthenosphere
How many large and small tectonic plates are there?
10-12 large ones and 20 small ones
Mantle Convection
Earth’s internal heat causing slow, circular movements in the semi-solid mantle
Ridge Push
Moves plates away from thee mid-ocean ridges as rock cools and becomes more dense.
Slab Pull
Pulls a plate along when its denser edge sinks beneath Earth’s surface
What are 3 processes that cause tectonic plates to move across the surface of Earth?
Ridge Push, Slab Pull, and Mantle Convection
Subduction
The process by which one tectonic plates is pulled beneath another plate
Magnetic Reversal
Change of the magnetic poles
What do plate tectonics help us know
Which volcanoes are active or form and where valuable resources are located, like coal
