a break in the lithosphere along which the rocks move.
the force that acts on the rock to change it's shape or volume.
what are the 3 kinds of tress that can occur in the crust?
tension, compression, shearing.
what does tension do to the crust, which causes what to happen to the rock so it becomes thinner in the middle?(2 plates moving apart)
what does compression do to a rock until it does 1 of what 2 things? (2plates pushing against each other)
2.folds or breaks
what does shearing do to a rock in different directions or different speeds causing them to what, and what, or what their what?(2 plates passing each other)
4.hange their shape
what are seismic waves generated by?
what are the 3 kinds of waves?
primary, secondary, and surface waves.
what do seismic waves travel through?
give an example or comparison of seismic waves.
like when the waves travel through a rope when you shake it.
the point where this energy release first occurs is the focus of an earthquake.
what is the plural of focus?
the foci of most earthquakes are within how far from earths surface?
hw deep have a few foci been recorded?
what are produced and travel outward from the foucs?
what is the epicenter?
the point of earths surface directly above the focus.
what is a seismograph?
an instrument to measure seismic waves from earthquakes.
what does the seismograph do?
they register the waves and record the time that each arrived.
what is the seismograph consist of?
a rotating drum of paper, and a pendelum with an attached pen.
how does the seismograph work?
when the seismic waves reach it the drum vibrates but the pen stays at the rest.
what is the paper record of the seismic event called?
which waves out of the three types are the fastest?
which of the 3 types of waves stop at the liquid core?
which of the 3 types of waves makes the MOST destruction?
which of the 3 kinds of waves are the cause to move rocks back and forth?
which of the 3 types of waves move rocks in a backward rolling motion, side to side, and swaying motion.
which of the 3 types of waves cause rocks to move at a right angle, and the direction of the wave travel.
the energy that is released when the height of the lines traced on the paper of seismograph of the earthquake.
what scale is used to describe the strength of an earthquake?
when wet soil shakes from an earthquake and becomes more liquidy.
what happens if liquefacation occurs underneath buildings?
the buildings can collapse or sink into the soil. people living in high risk earthquake areas should avoid building their homes on loose soil.
why do surface waves cause the most damage from an earthquake?
because because the buildings cant withstand the intense shaking so they move in different directions. and because they combine with p and s waves.
vibrations produced by the breaking of rock.
rocks bent and stretched out of shape by force.
constant motions of plates.
forces on either side of fault cause rok to slide past each other.
limits to how far rocks can bend and stratch.
force that pulls rock apart.
rocks on either side of the fault move past each other without much upward or downward movement.
results from tension, pulling rock apart;where the rock above the fault surface drops in relation to rock below the fault surface.
results from compression forces squeezing rocks together ;rock above the fault surface drops in relation to rock below the fault surface.
what is the first step in seismic pressure?
rough edges catch due to friction temporarily halting movement along a fault.
what is the second step in seismic pressure?
forces keep driving the rocks to move and pressure builds.
what is the 3rd step in seismic pressure?
stress causes the rocks to bend and change shape.
what is the 4th step in seismic pressure?
rocks bend beyond their elastic limit,break, move along the fault, and return to their original shape.
what is the last step in seismic pressure?
an earthquake results.