Plate Tectonics Theory Flashcards
What are the three main types of plate boundaries?
Divergent, Convergent, Transform
What is the lithosphere?
The rigid outer layer of the Earth consisting of the crust and upper mantle
What is the asthenosphere?
The semi-fluid layer of the Earth’s mantle on which the lithospheric plates float
What drives plate tectonics?
Heat from the Earth’s core causes mantle convection, which moves the plates
What is mantle convection?
The process by which heat from the Earth’s core causes material in the mantle to rise, cool, and sink, creating a cycle that drives plate movement
What is slab pull?
A force generated by the sinking of a dense oceanic plate at subduction zone, pulling the rest of the plate with it
What is ridge push?
A force that occurs at mid-ocean ridges, where rising magma pushes oceanic plates apart, driving plate motion
What happens at a divergent plate boundary?
Plates move away from each other, often forming mid-ocean ridges of rift valleys
What are the main features of a convergent plate boundary?
Plates move towards each other, which can cause subduction zones, mountain ranges, or deep ocean trenches
What occurs at a transform plate boundary?
Plates slide past each other horizontally, causing faults and earthquakes
What is subduction?
The process where one tectonic plate slides beneath another at a convergent plate boundary, often forming a trench
What is a mid-ocean ridge?
An underwater mountain range formed by divergent plate boundaries, where new oceanic crust is created
Give an example of a convergent plate boundary
The collision of the Indian plate and the Eurasian plate (the Himalayas)
What are ocean trenches?
Deep depressions in the ocean floor formed at subduction zones, where one plate is forced beneath another
What is an example of a transform fault?
The San Andreas fault in California
What is the theory of plate tectonics?
The theory that explains the movement of the Earth’s lithosphere on the more fluid asthenosphere beneath it, causing the formation of continents, earthquakes, and volcanoes
What is a hotspot?
A stationary area of volcanic activity beneath a tectonic plate, causing chains of islands, such as Hawaii
What happens when two continental plates collide?
The plates crumple and fold, forming mountain ranges, like the collision between the Indian and Eurasian plates forming the Himalayas
What is the evidence for plate tectonics?
Fossil distribution across continents amongst the fit of said continents between each other
What is the Wilson Cycle?
The cycle of ocean basin formation and closure due to plate tectonic processes, from rifting to subduction
