| A | B |
|---|
| earthquake | shaking and trembling that results from the movement of rock beneath Earth's surface. |
| stress | force that acts on rock to change its schange its shape or volume |
| shearing | stress that pushes a mass of rock in two opposite directions |
| tension | stress force that pulls on the crust, stretching it to become thinnner in the middle. |
| compression | e stress force that squeezes rock until it folds or breaks apart. |
| deformation | any change in the colume or shape in Earth's crust. |
| fault | break in Earth's crust where slabs of crust slip past each other |
| strike slip fault | rocks on either side of the fault slip past each other sideways with little up or down motion. |
| normal fault | one block of rock lies above the fault while the other is below. The fault is at an angle and the hanging wall slides down. |
| hanging wall | top half of a fault |
| footwall | lower half of a fault |
| reverse fault | same structure as a normal fault but blocks movement in opposite directions |
| fault block mountain | when normal faults uplift a block of rock |
| folds | bends in rock that form when compression shortens and thickens part of Earth's crust. |
| anticline | a fold in rock that bends upward into an arch. |
| syncline | fold in rock that bends downward in the middle to form a bowl. |
| focus | point beneath Earth's surface where rock that is under stress breaks triggering an earthquake . |
| epicenter | point on the surface directly above the focus. Most damage occurs here from surface waves. |
| seismic waves | vibrations that travel through Earth carrying the energy released during an earthquake. |
| P Waves | earthquake waves that compress and expand the ground like an accordian (Primary waves) |
| S Waves | earthquake waves that vibrate form side to side as well as up and down. (secondary waves) |
| Surface Waves | produce most severe ground movements and move more slowly than P and S waves. They are in circular/wave motion. |
| seismograph | records the ground movements caused by seismic waves as they move through the Earth. |
| magnitude | measurement of earthquake strength based on seismic waves and movement along faults. |
| mercalli scale | rates intensity of earthquake, not precise measurement, scale of 1-12. |
| richter scale | only good for small nearby measures, scale of 1-10, Each number is 10x the energy of the previous number. |
| moment magnitude scale | estimates the total energy released, can measure any size at any distance, better than richter scale. |
| rift valley | valley formed when the land between two normal faults slides down. |
| liquefaction | occurs when an earthquakes violent shaking suddenly turns loose, soft soil into liquid mud. (likely where the soil is full of moisture.) |
| aftershock | an earthquake that occurs after a large earthquake in the same area, (may strike hours, days or months later) |
| tsunamis | large waves formed by the water displaced by an earthquake if its strong enough |
| base-isolated building | a building designed to reduce the amount of energy thast reaches the building during an earthquake (shock absorbing) |
| plateau | large flat area of land that is raised high above sea level. |
| fold | bend in rock |
| example of a reverse fault | Mt. Gould |
| example of a strike slip lateral fault | san andreas |
| example of folded mountains | appalachian mtns. |
| example of rift valley | death valley |
| example of anticline | black hills |
| example of syncline | illinois basin |
| example of lava plateau | columbia plateau |
| example of folded plateau | appalachian plateau |
| example of canyon | grand canyon |
| example of normal fault | sandia mountains |
| creep meters | uses a wire stretched across a fault to measure horizontal movement of the ground (strike slip faults) |
| laser-ranging devices | uses a laser beam to detect even tiny fault movements. can detect any change in distance to the reflector, horizontal movements, very accurate. |
| tiltmeter | measure tilting of the ground. Used by seismologists, consists of two bulbs that are filled with a liquid and connected by a hollow stem, like carpenters level, detects verticle movement. |
| satellite monitors | equipped with radar to make images of faults, detects mostly verticle movement, can detect horizontal movement. |
| 3 things that determine if rocks fold or fault | temperature, how pressure is applied, type of rock |
| What to do in an earthquake | drop, cover, hold |
