Question | Answer |
the shaking and trembling that results the movement of rock beneth the earth surface | earthquake |
two powerful forces that change rock and earths crust | squeezepull |
a force that acts on rock to change its shape or volume | stress |
the amount of space and object takes up | volume |
stress that pushes a mass of rock in two opposite directions | shearing |
stress that pulls on the crust, stretching rock so that it becomes thiner in the middle | tension |
stress that squeezes rock until it folds or breaks | compression |
any change in the volume or shape of earth crust | deformation |
a break in the crust where slabs of crust slip past each other | fault |
rocks on either side of the fault slip past each other sideways with little up or down mountains shearing transform | strike-slip fault |
the fault is at an angle so one block of rock lies above the fault and the other block lies below the fault tension and divergent | normal fault |
half of the fault that lies above | hanging wall |
half of the fault that lies below | footwall |
a type of fault where the hanging wall slides up compression convergent | reverse fault |
a force that opposes the motion of one surface as it moves across another surface | friction |
the rocks on both sides of the fault slide by each other with no sticking | low friction |
the sides of the fault jam together from time to time they break free small earth quakes occur | medium friction on a fault |
both sides of rock lockthe stress increases until it is strong enough to overcome the friction larger earthquakes occur | high friction on a fault |
a mountain that fomrs where a normal fault uplifts a block of rock | fault-block mountain |
where 2 plates move away from each other tnesion forces create many normal faultswhen 2 of these normal faults form parallel to each other, a block of rock is left lying between them. | beginning process of a fault-block mountain |
bend in rock that form when compression shortens and thickens part of earth's crust. | folds |
the collisions of 2 plates cause compression and folding of the crust. | compression of 2 plates cause an earthquake |
an up fold in a rock formed by comprssion of earth's crust | anticline |
a down fold in a rock formed by tension in earth's crust | syncline |
a large area of flatland elevated high above sealevel | plateau |
the lithesphere with in 100 kilometers of earth's surface | where an earthquake is centered |
the point beneath earth surface where rock that is stress breaks, triggering an earthquake. | focus |
the point on the surface directly above the focus | epicenter |
vibrations that travel through Earth carrying the energy released during an earthquake | scismic waves |
how close the location is to the epicenter | what determines how much the ground shakes during an earthquake. |
when rocks fracture at the focus deep in the the earth's crust. | when do earthquakes occur? |
primary waves | what are the first waves to occur in an earthquake? |
earthquake waves that compress and expand the ground like accordion | p waves |
earthquake waves that vibrate side to side as well as up and down shaking the ground back and forth. | s waves |
move more slowly than both p and s waves | how fast do surface waves move? |
shake building side to side or shake like ocean rolls | what do Surface Waves do? |
by a device called seismograph | how do we record and measure seismic waves |
electronic seismographmechanical seismograph | types of devices we use to record seismic waves |
a measurement of earthquake strength based on seismic waves and movement along faults. | magnitude |
developed to rate earthquakes according to their intesity. | Mercalli Scale |
a rating of the size of seismic waves as measured by a particular type of mechanical seismograph | Richter Scale |
Electronical instead of mechanical | what seismograph is used today? |
accurate measurements for small nearby earthquakes, but the scale doesn't work well for large or distant earthquakes. | how well does a Richter scale work? |
a rating system that estimates the total energy released by an earthquake | Moment Magnitude Scale |
rates earthquakes of all sizes, near or far | What does the Moment Magnitude Scale do? |
Richter ScaleMercalli ScaleMoment Magnitude Scale | What are the scales used to measure the strength of an earthquake? |
5.0 and above | A what magnitude on the Moment Magnitude Scale causes great distruction. |
By the seismic waves speed. | How is locating the epicenter? |
The energy of the seismic waves tat reach the surface is greatest at the epic center | At what point do seismic waves first reach the surface? |
they travel through earth by seismic waves | How does the energy of an earthquake travel through earth? |