Chapter 6 Test Flashcards
Tension stress
Pulls on the crust, stretching rock so it becomes thinner in the middle
Compression stress
Squeezes rock until it folds or breaks
Shearing stress
Pushes a mass rock in two opposite directions
Normal faults
Form when forces pull rocks apart along a divergent plate boundary; block of rock above fault moves down
Strike slip fault
Two blocks of rock slide horizontally past each other in opposite directions
Reverse fault
Forces pushes two blocks of rocks together w/ the rock moving up
Stress
Force that acts on rock to change its shape or volume
Epicenter
Point on the surface directly above the focus
Focus
Point beneath earths surface where rock under stress breaks to cause earthquakes
Primary waves
(P wave) Compression waves that travel through solids and liquids. Compressing and expanding the material they pass through
Secondary waves
(S wave) Only travel through solids and temporarily change the shape but not the volume of the material they pass through
Move slower than P waves
Surface waves
Move slower than P and S waves but can produce severe ground movement with a wavelike motion
Seismic waves
waves that carry energy of an earthquake away from the focus
Dormant volcano
Not active, but may become active
Extinct volcano
Unlikely to erupt again
