chapter 6 Flashcards
earthquakes
what are three land features caused by tectonics plate movement
ocean basins, mountains, volcanos
where are earthquakes the strongest?
epicenter
what does ten-fold on the Richter scale mean? (ranged from _ to _)
1 to 10
a familiar system of reporting the magnitude or energy of an earthquake
Richter scale
in general, the size of intensity of some measurable quantity (measurement of an earthquake’s energy)
magnitude
a push or pull on an object
force
the first earthquake wave that reaches a seismic station from an earthquake
P waves
rapid mass wasting of earth materials downhill
landslide
the angle of slope of a fault face or stratum, measured from the horizontal plane to the fault or stratum surface
dip
forces or stresses acting in opposite directions on different parts of the same object or substance
shear stress
the point on the earth’s surface directly above the place within the earth where an earthquake actually occurs (it’s focus)
epicenter
the tool used to measure the strength of an earthquake
seismograph
any change in the shape of a solid due to stresses exerted on the material
strain
how do geologists classify faults?
by the way two blocks of rock moved to form the fault
the second earthquake wave that reaches a seismic station from an earthquake
S waves
a far-reaching, devastating water wave caused by seismic activity
tsunami
any force exerted on the matter in an object
stress
what type of plate boundary is associated with plates sliding pass each other
transform
in geology, one of several kinds of earthquake waves that travel only along the surface of the earth
surface wave
the actual center of an earthquake’s activity deep underground
focus (hypocenter)
what type of plate boundary is associated with plates moving toward each other
convergent
list the two types of crust
oceanic and continental
a fault whose main motion is parallel to its dip direction
dip-slip fault
list three kinds of stress
compression, tension, shear
forces or stresses that act to pull an object or substance apart
tension stress
a stress crack in a rock that shows no indication of motion of the rock on either side of the rock
joint
a crack or joint in a rock where the rock on both sides the joint have moved relative to each other
fault
in general, a measure of the concentration of energy expended or the effects of energy releasers. The measurement of damage an earthquake causes using the Modified Mercalli Intensity scale
intensity
rates the destructiveness of the earthquake
Mercalli
the compass direction of an imaginary line drawn horizontally on the surface of a fault face or rock stratum
strike
an instrument that detects earthquake waves
seismometer
list three properties related to a strain
ductility, joint, brittle
forces or stresses that act to squeeze or crush an object or substance
compression stress
what type of plate boundary is associated with plates moving away from each other?
divergent
a faults resistance to movement depends on what two things?
how smooth and slippery the fall surface is
earthquakes are most common along?
divergent. convergent, transform tectonic plates
include oil, grease, and other substances used to reduce friction between surfaces
lubricant
when slippage in one location of the fault increases the amount of matter strain on other locked portions of the fault, and then those sections sometimes later; secondary earthquake that came from continue for days weeks and months after the main earthquake
aftershock
the amount of matter a material can endure without breaking
ductility
list and define two kinds of dip-slip faults
reverse (upper body of rocks slides upward relative to the lower body of the rock) and normal (the body of rock above the fault surface drops relative to the body of rock underneath the fault surface)
can aftershocks occur more than once and how long?
yes; for weeks, days, and months after the main earthquake
list and define the three boundaries
- divergent
- convergent
- transform
list three places seismic waves carry energy
away from the focus, through Earth’s interior, across the surface
what are the two safest type of buildings?
modern and strong; wooden structures and resting on rubber flooring. stronger and more flexible
