Chapter 6 Review

P wave

primary wave; the fastest wave generated by an earthquake and the first to be recorded by a seismograph

tension

stress that occurs when forces act to stretch an object

Intensity

the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude

Epicenter

the point on the Earth's surface directly above the focus of an earthquake

buoyant force

the upward force that keeps an object immersed in or floating on a fluid

surface waves

travel along the Earth's surface away from the epicenter

strain

A condition resulting from damaging a muscle or tendon

Stress

A force that acts on rock to change its shape or volume

transform boundary

A plate boundary where two plates move past each other in opposite directions

Richter scale

A scale that rates an earthquake's magnitude based on the size of its seismic waves.

convergent boundary

A tectonic plate boundary where two plates collide, come together, or crash into each other.

Seismometer

Instrument used to measure horizontal or vertical motion during an earthquake.

magnitude

Measure of the energy released during an earthquake

S waves

Secondary waves, shearing waves (vertical or horizontal) move up/down, doesn't move through liquid

Compression

Stress that squeezes rock until it folds or breaks

divergent boundary

The boundary between two tectonic plates that are moving away from each other

focus

The point beneath Earth's surface where rock breaks under stress and causes an earthquake

earthquake

a movement or trembling of the ground that is caused by a sudden release of energy when rocks along a fault move

shear

force directed parallel to a surface