| A | B |
|---|
| stress | the push pull force on the Earth's crust, changes the volume and shape |
| three types of stress | compression, tension, shearing |
| compression | whenrocks are squeezed together, pushes rocks up or down |
| tension | when rocks are pulled apart, thinner in the middle |
| shearing | rocks are pushed in opposite, horizontal directions |
| fault | a break or crack along which rocks move |
| joints | cracks from rock fractures |
| hanging wall | block of rock above a fault |
| foot wall | block of rock below a fault |
| normal fault | caused by tension, hanging wall moves down |
| reverse fault | from compression, hanging wall moves up |
| thrust fault | from compression, hanging wall slides over foot wall, older rocks pushed on top |
| lateral fault | one block moves left or right of second block |
| deformation | the fold, fault, or tilt due to stress |
| fault block mountains | normal faults form a series of mountains |
| rift valleys | a block of land between 2 normal faults slides downward |
| folding | a bend in a rock, ex, Appalachian Mtns |
| anticline | an upward fold |
| syncline | a downward fold |
| causes of folding | temp.hot, rocks will fold, pressure great=fold |
| ductile rocks | bendable rocks that will fold |
| brittle rocks | more likely to fault |
| gradual force | rocks will fold |
| sudden force | rocks will fault |
| Mercalli scale | not precise, rates by intensity, tells how affects people, buildings, land |
| Richter scale | measures strength from 1 to 10, local earthquakes only |
| Moment magnitude scale | measures total energy released, scale of 1 to 10 |
| epicenter | point on the crust above the focus |
| focus | underground point of origin |
| p waves | primary waves travel the fastest, compressional wave |
| s waves | second wave to reach surface, up and down waves |
| surface waves | roll along on surface, bend/twist surface of earth, slowest wave |
| seismic wave | earthquake waves, travel outward |
| seismograph | instrument that measures seismic waves |
| liquefication | soft soil turns into mud, triggers landslides |
| aftershocks | earthquakes that occur after a large earthquake |
| tsunami | tidal waves from earthquakes which occur beneath ocean floor |
| base isolated buildings | reduces energy from earthquake, building is build on shocks |
| creep meters | wire stretched across fault, measures horizontal movement |
| laser device | laser beam which detects fault movements |
| tiltmeter | measures tilting of ground, lever with two bulbs fulled with liquid |
| satellite monitor | makes pictures of the fault, distance from ground to satellite is recorded |
| plateau | flat topped rocks,high above sea level |
| domes | magma pushes up over rock layers, Black Hills |
