SCIENCE SQ1

The crust and the uppermost part of the mantle comprise the __________.

Lithosphere

The lithosphere is broken into large and small sections called __________.

Tectonic plates

Below the lithosphere is the __________.

Asthenosphere

It is about 180 km thick and contains hot, molten rocks (magma).

Asthenosphere

It can deform and reshape because of the hot, molten mantle.

Asthenosphere

The outermost layer of Earth where life exists is the __________.

Crust

The crust that makes up the continents is called the __________.

Continental crust

It is made mostly of light granitic rocks rich in aluminum silicates.

Continental crust

The crust beneath the ocean floor is called the __________.

Oceanic crust

It is composed of dense basaltic rocks and is about 7–10 km thick.

Oceanic crust

Below the crust is a semi-solid, rocky, and very hot layer called the __________.

Mantle

It makes up about 80% of Earth and contains most of Earth's mass.

Mantle

It is composed of ferromagnesian silicate rocks.

Mantle

The core has two distinct layers.

Outer core and Inner core

The only liquid layer of Earth is the __________.

Outer core

It has a diameter of about 1,200 km and is composed mostly of solid iron.

Inner core

It has an estimated temperature of about 6,000°C.

Inner core

The interface between the crust and the upper mantle is called the __________.

Mohorovičić Discontinuity

It is commonly called the __________.

Moho

Highly sensitive instruments that detect seismic waves are called __________.

Seismometers

Seismic waves are recorded by a __________.

Seismograph

The two types of seismic waves are __________ and __________.

Body waves and Surface waves

They travel through Earth's interior.

Body waves

They travel only along Earth's surface.

Surface waves

The first waves to arrive are the __________.

Primary waves (P-waves)

They are compressional waves.

Primary waves (P-waves)

They are transverse waves.

Secondary waves (S-waves)

They move particles up and down, perpendicular to the wave's direction.

Secondary waves (S-waves)

Earth once formed a single supercontinent called __________.

Pangaea

The superocean surrounding Pangaea was called __________.

Panthalassa

One of the earliest theories explaining Earth's changing surface was the __________.

Contraction Theory

Pangaea split into two supercontinents called __________ and __________.

Laurasia and Gondwana

It became present-day Africa, Antarctica, South America, Australia, and India.

Gondwana

It was proposed by Eduard Suess.

Gondwana

It became present-day Asia, Europe, and North America.

Laurasia

The seafloor spreading theory was proposed by __________.

Harry Hess

Forces that push plates together or pull them apart are called __________.

Driving forces

It is caused by heat rising from the core through the mantle.

Mantle convection

It occurs when a subducting slab sinks because it is colder and denser.

Slab pull

It occurs between two colliding plates.

Slab suction

It occurs when the lithosphere is pushed up by the asthenosphere at mid-ocean ridges.

Ridge push

Forces that oppose plate movement are called __________.

Resisting forces

Friction that resists subduction is called __________.

Collisional resistance

Friction due to plates sliding past each other is called __________.

Transform fault resistance

The force that resists the movement of lithospheric plates is called __________.

Drag force