Composition of the Earth and Plate Tectonics

What do scientists use to measure the rate of tectonic plate movement?

GPS (Global Positioning System)

Why do scientists look to the ocean floor to research the mantle?

because it is deep and has trenches

the liquid layer of the core

inner core

the solid layer of the core

inner core

what element makes up most of the Earth's core?

iron

the outermost, rocky layer of the Earth

lithosphere

three types of convergent boundaries

oceanic-oceanic, oceanic-continental, continental-continental

Density changes in the asthenosphere are caused by the flow of __________ energy from deep within the Earth.

thermal

boundary formed when tectonic plates slide past each other

transform boundary

What type of boundary produces earthquakes?

all of them (but mostly transform boundaries)

the "plastic" layer of the slow flowing rock in the mantle

asthenosphere

What causes tectonic plates to move?

convection currents in the mantle

boundary formed when tectonic plates collide

convergent boundary

three layers of the earth, based on their composition

crust, mantle, core

Mid-ocean ridges are the most common form of _____________ boundaries.

divergent boundaries

boundary formed when tectonic plates separate

divergent boundary

oceanic crust is denser than the continental crust because it contains more of which three elements?

iron, calcium, magnesium

the mantle contains more of the element _________ than the crust

magnesium

the strong, lower part of the mantle

mesosphere

What can form when 2 continental plates collide?

mountains

What are the 2 types of crust that a tectonic plate may contain?

oceanic (denser), continental (thicker)

three elements that make up most of the earth's crust

oxygen, silicon, aluminum

What is it called when two oceanic plates move apart and new crust is formed?

sea floor spreading (rising magma creates a new ocean floor)

What boundary is created during continental-oceanic crust collisions?

subduction zone

What are the large pieces of lithosphere that float on the asthenosphere called?

tectonic plates

How much of the Earth's mass is made up by the core?

1/3 (one third)

The theory that Earth is divided into plates that move around is called ...?

Plate Tectonics