3.1 Plate Tectonics Flashcards
What is the main cause of plate movement?
Convection currents in the mantle due to heat from the Earth’s core.
Name the two types of crust.
Continental crust (thicker, less dense) and oceanic crust (thinner, denser).
What are the three main types of plate boundaries?
Constructive, Destructive, and conservative
What happens at a constructive boundary?
Plates move apart, allowing magma to rise and form new crust.
Name an example of a constructive boundary.
Between the Eurasian and North American plates.
What happens at a destructive boundary?
Plates collide, causing subduction of oceanic crust or mountain formation.
Name an example of a destructive boundary.
The Nazca and South American plates, forming the Andes Mountains.
What is a subduction zone?
A region where an oceanic plate sinks beneath a continental plate.
Why does oceanic crust subduct beneath continental crust?
Because it is denser than continental crust.
What landforms are created at destructive boundaries?
Fold mountains, ocean trenches, and volcanic island arcs.
What landforms are created at constructive boundaries?
Ocean Ridges between two oceanic crusts and Rift Valley between two continental crusts
What is sea-floor spreading?
The formation of new oceanic crust at constructive boundaries.
What is an ocean trench?
A deep depression in the ocean floor at a subduction zone.
Name an example of an ocean trench and how deep it is
The Mariana Trench, the deepest part of the ocean is over 11km deep
What is a fold mountain?
A mountain range formed by the collision of continental plates.
Name an example of fold mountains and name the plates they form between
The Himalayas, formed by the collision of the Indian and Eurasian plates.
What is a volcanic island arc?
A curved chain of volcanic islands formed at an oceanic-oceanic subduction zone.
Name an example of a volcanic island arc.
The Philippine Islands.
What is a hotspot?
A region where a plume of magma rises through the mantle, creating volcanoes.
