Flashcards in Plate Tectonics Deck (27):
What are plate tectonics?
They are convection cells of magma within the mantle cause overriding crustal plates to move.
What is a crustal plate's speed?
Crustal plates move in a variety of directions at different rates of speed.
How many types of boundary interactions are there?
How many different way to boundary interactions interact with one another?
(Tension) plates going in different directions.
Where do divergent boundary interactions often occur?
On the ocean floor.
What is it called if a divergent boundary interaction happens on land?
A rift zone.
What do divergent boundary interactions result in?
Sea floor spreading. (how islands and volcanos are made)
What are examples of divergent boundary interactions?
Mid. Atlantic Ridge, Red Sea Spreading Center, East Africa Great Rift Valley.
(compression) 2 plates moving toward each other.
What do convergent boundary interactions result in?
Building mountains and major landform features.
Subduction equals what?
One plate descends below another plate.
Trench equals what?
Volcanic mountain range.
Subduction creates what?
Examples of Subduction...
Andes= NAZCA ->
What happens when you have cont. V.S. cont.?
No Subduction, Mt. building events, collision zone
What are some examples of volcanic island arcs?
Japan Islands, Philippines Islands, and Mariana Trench
What are examples of cont. V.S. cont.?
Indian pushing on the Tibet creating the Himalayans
What is a transform plate boundary?
Two plates moving side to side causing a shear stress
What's an example of a transform plate boundary?
San Andres Fault
What is the volcanic processes?
The nature of volcanic eruptions is determined by the chemistry of the magma.
What causes volcanic magma viscosity resistance to flow?
Silica and gases affect the viscosity.
What is high viscosity?
high resistance to flow, does not flow easily. (very sticky)
What is low viscosity?
low resistance to flow easily (like hot honey)
What is viscosity?
Resistance to flow
What causes a gentle eruption?
Low silica and gases, low viscosity, high temps, 2000F *all made of basalt*