Plate tectonics

sonar

a device that uses sound waves to measure distance to an object

mid-ocean ridge

a mountain range that is formed by seams that run along the floor of the ocean

The layer of the earth where mantle convection occurs and on which the earth's crust rests is the _____.

asthenosphere

convection

process of heat transfer by the circulation or movement of a gas, liquid, or plastic material

At a mid-ocean ridge, a crack forms along the oceanic crust causing __________.

seafloor spreading

transform boundary

the boundary created by two plates moving alongside each other

seafloor spreading

the process that occurs when new oceanic crust is formed through volcanic activity

magma

the result of an oceanic plate as it begins to melt while conforming to a subduction zone

plate tectonics

the theory that the lithosphere is broken into pieces that float on the asthenosphere

lithosphere

earth's crust and rigid portion of uppermost mantle

The plate tectonic theory can best be described as _____.

earth's natural process by which its lithospheric plates slowly move about because of movement in the asthenosphere

The layer of the earth that forms the earth's plates is the _____.

lithosphere

As subduction occurs, the oceanic crust moves from the ____________ toward a ___________

mid-ocean ridge deep-ocean trench.

1. asthenosphere 2. continental crust 3. convection 4. lithosphere 5. oceanic crust 6. plate tectonics

3 process of heat transfer by the circulation or movement of a gas, liquid, or plastic material 4 Earth's crust and rigid portion of uppermost mantle 5 the part of Earth's crust located beneath the oceans and seas 2 the part of Earth's crust that forms landmasses 6 the theory that the lithosphere is broken into pieces that float on the asthenosphere 1 the outer layer of the mantle; made up of plastic or semi-molten rock

The person who suggested that the continents were once a supercontinent, called Pangaea, that slowly drifted apart was ____________.

Alfred Wegener

The scientist's hypothesis that all of the continents were previously one large continent until something caused them to move apart is called _______________.

continental drift

The process of heat transfer thought to be responsible for the movement of the lithospheric plates on the surface of the earth is ____________.

convection

Mantle convection is a circulation of the heat emitted by the earth's _____.

core

Earth's mantle experiences convection currents that cause plates to move. Which of the following are the result(s) of the movements? Select all that apply.

mountain ranges volcanoes deep-ocean trenches

divergent boundary

the boundary created by two plates moving away from each other

convergent boundary

the boundary created by two plates moving toward each other

asthenosphere

the outer layer of the mantle; made up of plastic or semi-molten rock

oceanic crust

the part of Earth's crust located beneath the oceans and seas

continental crust

the part of Earth's crust that forms landmasses

subduction

the process in which a deep part of the ocean is formed by the intersection of an oceanic plate and continental plate

During the process of a subduction, the older oceanic crust is pulled by gravity down beneath the __________ and back into the ____________.

trench mantle