Lesson 3
What is the hypothesis called that all the continents were once joined together in a single landmass and have since drifted apart?
continental drift
Name for long chains of mountains that rise up from the ocean floor.
mid-ocean ridges
What is the theory that states Earth's plates are in slow, constant motion, driven by convection currents in the mantle.
plate tectonics
How does heat transferred within Earth?
convection
convection currents
What is a mountain that forms in Earth's crust when molten material, magma, reaches the surface.
volcano
What is the supercontinent from about 300 million years ago called?
Pangaea
How can scientists map mid-ocean ridges?
sonar
What is a deep valley where pieces of Earth's crust diverge on land?
rift valley
What causes convection current's in the mantle?
Heat from Earth's core
What does the Ring of Fire consist of?
volcanoes
Name one form of evidence Wegener had for his hypothesis.
fossils
land features
climate
What is the PROCESS that causes part of the ocean floor to sink back into the mantle?
subduction
Describe the movement of plates at a convergent boundary
colliding, coming together
Name the three types of heat transfer
convection
conduction
radiation
Where do volcanoes form?
along the boundaries of Earth's plates
hot spots
What was the name of the man who came up with the hypothesis for continental drift?
Alfred Wegener
What is the PROCESS called that adds crust to the ocean floor.
sea-floor spreading
Describe the movement of plates at a divergent boundary
moving away from each other, different directions
Would cooler or warmer soup be more dense?
cooler
What is magma called once it reaches the surface?
lava
Why was Wegener's hypothesis rejected at first?
Couldn't explain how or why continents moved.
Where is the newest oceanic crust located at?
mid-ocean ridges
Describe the movement of plates at a transform boundary.
slip past each other moving in opposite directions
What are the three things that set convection currents into motion?
heating and cooling of a fluid
changes in the fluid's density
force of gravity
Name an example of an island arc.
answers may vary