Vocab
A chain of volcanoes in the middle of the ocean
Mid-Ocean Ridge
The hottest and deepest layer of the Earth
Inner core
The theory proposed by Alfred Wegener that continents slowly drifted to their current location
Continental Drift
__________________ are broken pieces of the lithosphere
tectonic plates
The age of the seafloor at mid-ocean ridges is younger or older than at trenches
younger
the ______________ floats on the athenosphere
Lithosphere
Tectonic plates move at approximately 2 ________
cm/year
The name of a supercontinent that literally means "all land"
Pangaea
The type of plate boundary that occurs when plates move towards one another
Convergent
convection currents occur in the _____________
Asthenosphere
A deep valley that forms when two plate move apart
Rift Valley
_______________ in the asthenosphere drives plate motion
Convection current
___________ of animals supported the theory of Continental Drift as they could not have swum across the ocean.
Fossils
_________ forces occur at divergent plate boundaries
Tension forces
What are two different types of crust?
Oceanic and continental
Force that makes two plates slide past one another
Shear force
How did Hawaii form?
Hotspot
Why did scientists not believe Wegener
What feature occurs at subduction zones?
Trench under water, chain of volcanos on land
Which type of crust is more dense?
oceanic
A process that contributes to plate motion at subduction zones by pulling the lithosphere deeper into the asthenosphere
Slab Pull
A crack in the Earth's crust associated with earthquakes and plate movement
Fault
List the four pieces of evidence that Wegener used to support his theory
Fossils, Continental shape, Matching rock assemblages, Glacial deposits
At what type of plate boundary do the majority of earthquakes occur?
Convergent (RING OF FIRE!)
What device did scientists use to map the ocean floor?
Sonar