Tectonics Flashcards
What is the crust?
The outermost layer of the earth.
What/Where is the mantle?
The crusts’ slabs float on the mantle.
What is the mantle?
A layer of molten of rock with rock inside of it
Why do plates move?
Convection Currents in the mantle
What are convection currents?
Heat rising, transfer of heat from one place to another through a liquid or gas
What are the two crusts that make up plates?
Continental, thick, less dense 30-50km
Oceanic, thinner, dense, 5-10km
What is a destructive plate margin?
(Ridge Push)
Two plates move towards each other
When the two plates meet, the weak but dense oceanic plate subduct
This creates gas-rich magma, causing volcanoes
What happens at a constructive margin?
(Slab Pull)
Plates move apart, magma rises to fill the gap and cools at the surface, causing more land and a crust to form
What happens at a conservative margin?
Plates shuffle next to eachother at varying speeds in the same direction
Nothing is Created or Destroyed
Rift Valleys: Why do we get volcanos at destructive margins?
Oceanic plates subduct
A pool of magma forms
The magma rises and Leaks through vents causing a volcano
Rift Valleys: Why do we get volcanos at constructive margins?
Gap widens, magma/lava comes through
Why do we get earthquakes at destructive margins?
Tension builds when the subducting plate gets stuck
Why do we get earthquakes at destructive margins?
Tension builds in cracks along the plates as they move away from eachother
Why do we get earthquakes at conservative margins?
Tension builds when plates grind against eachother
Why do we get earthquakes from each plate margin?
Plates jerking past eachother causes shockwaves to occur
