APES - Notes 4A

What is the core made of and what does it do?

Nickel, iron, and radioactive elements; releases heat that drives mantle convection

What is the difference between the inner and outer core?

Inner core = solid metal

outer core 

liquid metal that creates Earth’s magnetic field. 

What is the mantle?

Makes up most of Earth’s Interior (Oreo)

What is the lithosphere?

Rigid outer layer made of crust + upper mantle.

What is the asthenosphere?

Partially melted

Is oceanic crust more or less dense than continental crust?

More dense.

What happens at a subduction zone?

The denser plate sinks beneath the other

How do mountain ranges form?

At continental–continental convergent boundaries

What happens at a divergent boundary?

Plates move apart as rising magma forms new crust.

What features are created at divergent boundaries?

Rift zones

What types of crust are involved in a mid-ocean ridge?

Oceanic–oceanic divergent crust.

What is a transform boundary?

Plates slide sideways past each other.

What features does a transform boundary create?

Faults

What type of crust is involved in a transform boundary?

Any crust (continental or oceanic).

What is a subduction zone?

A convergent boundary where the denser plate sinks beneath the less dense plate.

What features does a subduction zone create?

Trenches

What type of crust is involved in a subduction zone?

Oceanic–continental OR oceanic–oceanic.

What is an island arc?

A chain of volcanic islands formed above a subducting oceanic plate.

What features does an island arc create?

Volcanoes

What type of crust is involved in an island arc?

Oceanic–oceanic convergence.

What is an orogeny?

A mountain-building event at a continental–continental convergent boundary.

What features are created in an orogeny?

Large mountain ranges (ex: Himalayas).

What type of crust is involved in an orogeny?

Continental–continental.

What is a rift zone?

A place where continental plates pull apart.

What features does a rift zone create?

Rift valleys

What type of crust is involved in a rift zone?

Continental–continental divergent boundary.

What is a mid-ocean ridge?

Underwater mountain chain where new ocean crust forms from rising magma.

What features does a mid-ocean ridge create?

New seafloor

What type of crust is involved in a mid-ocean ridge?

Oceanic–oceanic divergent crust.

What is a hot spot?

A fixed plume of rising magma that creates volcanoes as a tectonic plate moves over it.

What features does a hot spot create?

Volcanic islands (ex: Hawaii)

What type of crust is involved in a hot spot?

Either continental or oceanic.

What causes mantle convection?

Heat from the core makes magma rise (less dense) and sink when cool (more dense).

What boundary creates the most powerful earthquakes?

Transform and convergent (especially subduction zones).

What is seafloor spreading?

Creation of new oceanic crust at mid-ocean ridges as plates diverge.

Why do oceanic plates subduct instead of continental plates?

They are more dense