Notes on Plate Tectonics Don’t Break Your Plate Notes on Plate Tectonics

Key Points Plate tectonics accounts for several features on the earth’s surface Seafloor spreading Subduction zones Earthquakes Volcanoes Mountain ranges Plates move due to mantle convection

How do plates move? The plates of the Earth float on top of the aesthenosphere When mantle rock near the Earth’s core heats up it becomes less dense and rises while the cooler rock near the surface sinks—mantle convection Moves plates a few centimeters each year

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Three types of plate boundaries: Divergent Transform Convergent

Divergent Boundaries New crust is created as two plates pull away from each other If two oceanic plates, the ocean will grow wider—seafloor spreading If two continental plates, creates a rift that will form two different land masses Fills with water in the rift

Transform Boundaries Two plates are sliding horizontally past one another Sometimes known as faults Earthquakes take place along these boundaries

Convergent There are 3 types of convergent boundaries: Oceanic-oceanic convergence Continental-continental convergence Oceanic-continental convergence Crust is destroyed and recycled back into the Earth’s interior as one plate sinks below another plate—subduction zones Mountains and volcanoes often form here

Oceanic-Oceanic Convergence When one oceanic plate subducts under another: A deep ocean trench is formed Creates undersea volcanoes that over time, can build up to form volcanic islands

Continental-Continental Convergence When two continental plates meet head-on, neither one subducts. Plates tend to buckle and rise up/sideways to form mountain ranges i.e. Himalayan Mountains

Oceanic-Continental Convergence When an oceanic plate subducts below a continental plate: The continental plate rises to form mountains When oceanic plate sinks deep, some pieces break off and get locked in place—leads to earthquakes

Which of the following is not a plate boundary? Divergent Convergent Transvergent Transform 20

Where are mountains and volcanoes often found? Subduction Zones Mid-ocean Ridge Seafloor Spreading 20 Seconds Remaining

Which of the following is NOT a type of convergent boundary? Ocean-ocean Continental-ocean Continental-continental Continental-sea 20

This type of boundary is two plates pulling away from each other to create new crust. Convergent Divergent Transform 20

This boundary type has two plates sliding past each other Convergent Divergent Transform 20

This is where one plate sinks below another, melting back into the mantle. Transform boundary Subduction zone Mid-ocean ridge Divergent boundary 20

How do the tectonic plates move? Convection currents in the mantle Convection currents in the inner core Conduction in the mantle 20