Continental Drift
Who was the scientist who proposed that the continents were once joined in a single landmass?
Alfred Wegener
Who was the scientist who proposed the idea of seafloor spreading?
Harry Hess
Which type of boundary has two plates coming together?
convergent boundary
What causes the Earth's plates to move?
Convection currents in the mantle!
Earthquakes typically occur at this type of boundary.
Transform boundary
Pangaea
In seafloor spreading, new crust is added to the ocean floor along a ___________________.
mid-ocean ridge
Which type of boundary has two plates moving apart from each other?
divergent boundary
The theory that states that Earth's plates are in constant slow motion is called _________________.
The San Andreas Fault in California is located at a ______________ boundary.
Wegener noticed that the same ______________ occurred on now separated landmasses.
fossils
Hess noted that rocks closest to the mid-ocean ridge were always ______________ than the rocks further away.
Younger
Which type of boundary has two plates sliding past each other?
transform boundary
List the 5 mechanical layers of Earth from the outermost to the innermost layer.
Lithosphere, Asthenosphere, Mesosphere, Outer Core, Inner Core
The Himalayan mountain range is located at a ___________________ boundary.
convergent
Wegener noticed that when he pieced together the continents ______________ & ________________ lined up.
coalfields & mountain ranges
Old crust eventually sinks back into the mantle at deep-ocean trenches in a process called ________________.
Subduction
When two continental plates collide _______________ form.
mountains or volcanoes
List three features that can be created convergent boundaries.
mountains, volcanoes, & trenches
The Mid-Atlantic Ridge is located at a ______________ boundary.
divergent
Why was Wegener's theory of continental drift originally rejected?
Wegner couldn't explain WHY the continents moved.
What was Harry Hess's three pieces of evidence for seafloor spreading?
1. Molten material evidence
2. Magnetic stripe evidence
3. Drilling sample evidence.
rift valley
When an oceanic and a continental plate collide, subduction will occur and a ____________ will form.
The East African Rift is located at a ________________ boundary.
divergent