Bju press earth science chapter 6

surface waves

seismic waves that travel along the Earth's surface

Shear stress

stress that occurs when forces act in parallel but opposite directions, pushing parts of a solid in opposite directions

P waves (Primary waves)

travel through liquids and solids, push and pull, faster, arrive first

S waves (secondary waves)

travel through solids only; cause rock to move in a side-to-side or up & down motion, slower waves

Fault

(geology) a crack in the earth's crust resulting from the displacement of one side with respect to the other

Hazard

A danger or risk.

Seismograph

A device that records ground movements caused by seismic waves as they move through Earth

Tsunami

A giant wave usually caused by an earthquake beneath the ocean floor.

Intensity

A measure of how much damage actually results from earthquakes

convergent boundary

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

Seismometer

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

Stress

Is a force exerted inside a material, A force that acts on rock to change its shape or volume

magnitude

Measure of the energy released during an earthquake

Epicenter

Point on Earth's surface directly above an earthquake's focus

Risk

Possibility of injury or death

joints

Rocks under stress form cracks are called this

Love waves

Surface waves that shear the ground in a horizontal direction. Can only travel through solids. Third to arrive.

Rayleigh waves

Surface waves that travel in a backward-rotating, elliptical motion, causing both vertical and horizontal ground movement. Can travel through solid, liquid, and gas. Fourth to arrive. Dangerous.

Ductility

The amount of strain a material can endure without breaking

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

The shaking that results from the movement of rock beneath Earth's surface. Result if fault slipping

Richter scale

a logarithmic scale of 1 to 10 used to express the energy released by an earthquake

landslide

a slide of a large mass of dirt and rock down a mountain or cliff

after shock

a smaller earthquake following the main shock of a large earthquake.