SCIENCE SQ1

What comprises the lithosphere?

The crust and the uppermost part of the mantle.

What are the large and small sections of the lithosphere called?

Tectonic plates.

What lies below the lithosphere?

Asthenosphere.

What is the thickness and characteristic of the asthenosphere?

About 180 km thick and contains hot, molten rocks (magma).

What allows the asthenosphere to deform and reshape?

The hot, molten mantle.

What is the outermost layer of Earth where life exists?

Crust.

What is the crust that makes up the continents called?

Continental crust.

What type of rocks compose the continental crust?

Light granitic rocks rich in aluminum silicates.

What is the crust beneath the ocean floor called?

Oceanic crust.

What are the characteristics of oceanic crust?

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

What lies below the crust?

Mantle.

What percentage of Earth does the mantle make up?

About 80% of Earth and contains most of Earth's mass.

What type of rocks is the mantle composed of?

Ferromagnesian silicate rocks.

What are the two distinct layers of the core?

Outer core and Inner core.

What is the only liquid layer of Earth?

Outer core.

What is the diameter and composition of the inner core?

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

What is the estimated temperature of the inner core?

About 6,000°C.

What is the interface between the crust and the upper mantle called?

Mohorovičić Discontinuity (Moho).

What instrument detects seismic waves?

Seismometers.

What records seismic waves?

Seismograph.

What are the two types of seismic waves?

Body waves and Surface waves.

Which seismic waves travel through Earth's interior?

Body waves.

Which seismic waves travel only along Earth's surface?

Surface waves.

What are the first waves to arrive during an earthquake?

Primary waves (P-waves).

What type of waves are primary waves?

Compressional waves.

What type of waves are secondary waves?

Transverse waves.

How do secondary waves move particles?

Up and down, perpendicular to the wave's direction.

What was the name of the single supercontinent that Earth once formed?

Pangaea.

What was the name of the superocean surrounding Pangaea?

Panthalassa.

What was one of the earliest theories explaining Earth's changing surface?

Contraction Theory.

What two supercontinents did Pangaea split into?

Laurasia and Gondwana.

What modern regions did Gondwana become?

Africa, Antarctica, South America, Australia, and India.

Who proposed the theory of Gondwana?

Eduard Suess.

What modern regions did Laurasia become?

Asia, Europe, and North America.

Who proposed the seafloor spreading theory?

Harry Hess.

What are the forces that push plates together or pull them apart called?

Driving forces.

What causes mantle convection?

Heat rising from the core through the mantle.

What occurs when a subducting slab sinks?

Slab pull.

What occurs between two colliding plates?

Slab suction.

What happens at mid-ocean ridges when the lithosphere is pushed up?

Ridge push.

What are the forces that oppose plate movement called?

Resisting forces.

What is the friction that resists subduction called?

Collisional resistance.

What is the friction due to plates sliding past each other called?

Transform fault resistance.

What is the force that resists the movement of lithospheric plates called?

Drag force.