Chapter 6 Vocabulary

Series of low frequency shock waves (like sound waves), traveling through the earth.

An instrument that measures earth waves.

A measure of force exerted within an object. There are three main kinds of stress: Compression - stepping on an empty can Tension- pulling on a rope in tug of war Shear - forces acting in opposite directions on different parts of the same object. This stress produces earthquakes. Example - press sideways on a block of jello, shear stress in middle of jello

Spreading zones along some plate margins. The plate sections are moving apart, or diverging.

Plates are moving toward each other or converging.

Places where plates slide past each other in opposite directions along long cracks in the crust.

Occurs when the sections of rock on opposite sides of the crack move relative to each other.

The actual center of an underground earthquake

Point on the earths surface directly above the place inside the earth where the earthquake actually happened

Used to report the energy or strength of an earthquake

A measure of the energy released by an earthquake

A measure of the damage caused by an earthquake

A far reaching devastating water wave caused by an earthquake

The direction of a fault

A fault’s motion that is parallel to its dip (up and down). 2 kinds of dip- slip faults: Normal fault - when the block above the fault surface drops in relation to the block under the fault Reverse fault - when the upper block rose in relation to the lower block. If the dip is less than a 45 degree angle it is a Thrust Fault

When the only motion along the fault is horizontal (or called transform faults)