A | B |
earthquake | the shaking that results from the movement of rock beneath Earth's surface |
stress | a force that acts on a rock to change its shape or volume |
shearing | stess that pushes a mass of rock in opposite direction |
deformation | a change in the volume or shape of Earth's crust |
fault | a break or crack in Earth lithosphere along which the rocks move |
strike-slip fault | a type of fault where rocks on either side move past each other sideways with little up-or-down motion |
kinetic energy | energy of motion |
potential energy | stored energy |
elastic rebound | the sudden release of stress in rock that returns to its normal shape |
convergent boundary | two plates collide to form earthquakes and volcanoes |
New Madrid fault | fault zone in southern Illinois area |
San Andreas fault | transform boundary in California |
triangulation | using 3 seismograms to located an epicenter |
focus | the point beneath Earth's surface where rock breaks under stress and causes an earthquake |
epicenter | the point on Earth's surface directly above the earthquake's focus |
seismic waves | a vibration that travels through Earth carrying the energy released during an earthquake |
P waves | the type of waves that compress and expand the ground |
S Waves | the type of waves that move the ground up and down or side to side |
surface waves | the type of seismic wave that forms when P waves and S waves reach Earth's surface |
seismograph | a device that records ground movements caused by seismic waves as they move through Earth |
magnitude | the measurement of an earthquake's strength based on seismic waves and movement along faults |
Mercalli scale | a scale that rates earthquakes according to their intensity and how much damage they cause |
Richter scale | a scale that rates seismic waves as measured by a mechanical seismograph |
moment magnitude scale | a scale that rates earthquakes by estimating the total energy released by an earthquake |
liquefaction | the process by which an earthquake's violent movement suddenly turns loose soil into liquid mud |
aftershock | an earthquake that occurs after a larger earthquake in the same area |
tsunamis | a giant wave caused by an earthquake on the ocean floor |
base-isolated building | a building mounted on bearings designed to absorb the energy of an earthquake |