Plate Tectonics (Week 8 Lecture 11) Flashcards
How many large plates are there?
7
True or False: The plates glide over the mantle.
True
______ is a scientific theory describing the large-scale motion of seven large plates and the movements of a larger number of smaller plates of theEarth’slithosphere
Plate Tectonics
The driving force behind plate tectonics is ______ in the ______.
Convection, mantle
What are the three relative motions of plate tectonics?
Convergent, divergent, or transform
True or False: The relative movement of the plates typically ranges from zero to 100mm annually.
True
______ is a theory that explained how continents shift position on Earth’s surface.
Continental drift
Who proposed the idea of continental drift?
Alfred Wegner
______ are gaps between tectonic plates that mantle the Earth like seams on a baseball.
Mid-ocean ridges
Where does the convection occur in plate tectonics?
Mid-ocean ridges
______ are where two tectonic plates meet and one slides beneath the other back into the mantle, the layer underneath the crust. The cold, sinking plate pulls the crust behind it downward.
Subduction zones
What is the name of the area found along subduction zones where volcanoes are found
“Ring of Fire”
True or False: The ring of fire consists of 75% of the world’s active and dormant volcanoes.
True
Where do the 81% of the world’s largest earthquakes occur?
Ring of Fire
What are the three categories plate tectonics are divided into?
Major ( >20 million km2)
Minor (< 20 million km2 but > 1)
Micro (< 1 million km2)
What are the 7-8 major plates?
Pacific plate, Eurasian plate, Antarctic plate, South American plate, North American plate, African plate, Indo-Australian plate (could be considered two (Australian and Indian plate) )
What is the largest plate?
Pacific plate
True or False: Plate tectonics don’t move relative of each other.
False, they do move relative of each other
True or False: Plate tectonics interact along their boundaries, where they converge, diverge, or slip past one another.
True
True or False: Mountains rise when plates diverge and oceans form when plates converge.
Falase, oceans = diverge, moutains = converge
______ mark slip-sliding plates.
Transform margins
______ are two plates are spreading apart as at seafloor-spreading ridges or continental rift zones.
Divergent margins
______ are pushing and spreading apart atmid-ocean ridgesand pulling and sinking downward at subduction zones.
Subduction zones or convergent margins
True or False: Ocean floors are a distinctive morphological feature ofconvergent plate boundaries.
True
True or False: The material lost along convergent boundaries is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading.
True
Continental plates are made or ______ whereas oceanic plates are made of ______.
Granite, basalt
True or False: Tectonic plates are able to move because the Earth’s lithosphere has weakermechanical strengththan the underlyingasthenosphere.
False, Earth has greater mechanical strength.
True or False: Plate movement is thought to be driven by a combination of motion of the seafloor away from the spreading ridge and drag, with downward suction, at the subduction zones.
True
