APES 4.1

APES Topic 4.1 flashcards

Five

The Earth has this many layers.

The Crust

Earths outer layer. Solid, brittle, made entirely of light elements. Makes up less than 1% of the planets mass.

The Mantle

2900 km thick. Made of dense, iron rich materials. Makes up 64% of the total mass of the Earth.

The Lithosphere

Solid layer that includes the crust and uppermost part of the mantle. Divided into huge pieces called tectonic plates.

The Aesthenosphere

100 km thick, solid layer. Circulates convection cells which allows tectonic plates to move on top of it.

The Core

center of the Earth

Outer core

made of liquid nickel and iron.

Inner core

Radius of 1228km. made of solid nickel and iron.

convection current causing plate movement

As semi molten rock in the mantle is heated it becomes less dense than its surroundings and rises. As it reaches the crust above, it spreads out carrying the plates above with it. As the semi-molten rock then cools, it gradually sinks back down to be re-heated.

Ring of Fire

The area where most of the geological activity of the Earth takes place, at the boundaries of tectonic plates.

convergent

come together

divergent

move away

transform

move past

Convergent Boundary

Boundary where tectonic plates collide. Subduction zone is a specific type of this boundary.

Subduction zone

A specific type of convergent boundary where one plate sinks or bends beneath another.

Convergent

What boundary causes earthquakes, mountains, & volcanoes (depending on region)

Divergent Plates

These plates move away from each other. It forms rift valleys, earthquakes & possible volcanoes.

Seafloor spreading

What is it called when magma reaches the surface and new rocks form? It brings copper, lead, and silver into the Earth’s surface.

Transform/Strike Slip fault boundaries

causes earthquakes when stored energy is released from locked plates.

Fault Lines

a break in the Earths crust, when rocks that are under stress suddenly break a series of ground vibrations are set off.

Richter Scale

The size of the earthquake is measured by this scale. Its a logarithmic scale, a value increases by a factor of 10 for each unit increase.

Island Arcs

long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries.

Hot spots

volcanic regions thought to be fed by underlying mantle. Anonymously hot compared with the surrounding mantle.