Geology and Earth Structure

What is geology?

The study of the earth, from seismic shifts and mountain formation down to tiny rock and mineral formations.

What are the layers of the Earth, from center outward?

Inner core, outer core, mantle, moving plates, crust.

What is the inner core?

A solid, mostly metallic sphere of iron and nickel at the Earth's center.

What is the outer core?

The layer surrounding the inner core, made mostly of liquid metal.

What is the mantle?

The semisolid rock region surrounding the outer core.

What sits between the mantle and the crust?

A layer of moving plates that the crust rests on.

What sits on the crust?

The continents and oceans.

What is the lithosphere?

The upper mantle and crust together — the collection of major plates the crust sits on.

Why do the Earth's plates move?

Pressure below the surface, heat exchange between mantle and crust, and the composition of those layers.

What is continental drift?

The process of plate movement that explains the change from the single landmass Pangea to today's separated continents.

What was Pangea?

The single unified landmass that existed before the continents separated.

What happens at plate boundaries?

Heavy friction and geologic activity — earthquakes and volcanoes are associated with them.

What are the three main types of rock?

Igneous, sedimentary and metamorphic.

How does igneous rock form?

When magma or lava cools.

Which rock type makes up most of the Earth's crust?

Igneous rock.

What is sedimentary rock made of?

Smaller sediments and inorganic material.

How does metamorphic rock form?

When igneous or sedimentary rock is exposed and altered by changes in temperature or pressure.

What is the Richter scale?

The scale used to measure the magnitude of earthquakes.