Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
57 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
eathquakes
|
natural vibrations of the ground caused by movement along gigantic fractures in Earths crust
|
|
|
|
stress
|
forces per unit area acting on a material, exceeds the strength of the rocks involved
|
|
|
|
three types of stress
|
compression, tension, shear
|
|
|
|
compression
|
stress that decreases the volume of a material
|
|
|
|
tension
|
stress that pulls a material apart
|
|
|
|
shear
|
stress that causes a material to twist
|
|
|
|
strain
|
deformation of materials in response to stress
|
|
|
|
stress-strain curve
|
when stress applied to a rock is plotted against strain
|
|
|
|
straight segment on stress-strain curve
|
low stress: elastic strain of a material
|
|
|
|
elastic strain
|
cAuses a material to bend and stretch
|
|
|
|
ductile deformation
|
when stress exceeds a certain value
|
|
|
|
ductile deformation
|
curved segment, produces permanent deformation
|
|
|
|
brittle materials
|
glass, plastics, wood, fail before ductile deformation
|
|
|
|
ductile materials
|
rubber, silicon putty, metals, undergo a great deal of ductile deformation before failure, or may not fail at all
|
|
|
|
failure
|
when stress exceeds the strength of a material
|
|
|
|
earth depth for material types
|
brittle: low temps at earths crust, but become ductile at high temps at greater depths
|
|
|
|
fracture or system of fractures along which movement occurs
|
fAult
|
|
|
|
fault plane
|
surface along which movement takes plAce
|
|
|
|
reverse faults
|
horizontal compression
|
|
|
|
normal fault
|
fractures caused by horizontal tension
|
|
|
|
strike-slip faults
|
fractures caused by horizontal shear
|
|
|
|
seismic waves
|
vibrations on the ground during earthquakes
|
|
|
|
p waves
|
squeeze and pull rocks in same direction
|
|
|
|
s waves
|
cause rocks to move at right angles in relation to the direction of the waves
|
|
|
|
surface waves
|
move in two directions as they pass through rock
|
|
|
|
body waves
|
p and s waves
|
|
|
|
focus
|
where an earthquAke originates
|
several km below surface
|
|
|
epicenter
|
point on surface directly above the focus
|
|
|
|
eq per yr
|
over 1 mil
|
|
|
|
magnitude
|
amount of energy released during an earthquAke
|
|
|
|
Richter scale
|
based on the size of the largest seismic waves generated by the quake
|
|
|
|
Richter scale
|
each successive number in the scale represents an increase in seismic wave size, amplitude, of a factor of 10
|
|
|
|
magnitude 8 earthquAke
|
ten times larger than magnitude 7 earthquake, 100 times largwr than magnitude 6 quake
|
|
|
|
magnitude 8 quake
|
releases about 32 times the energy of magnitude 7 quAke and over 1000 times the energy of magnitude 6 quake
|
|
|
|
moment magnitude scale
|
takes into account the size of the fault rupture, the amount of movement along the fault, and the rock's stiffness
|
based on group on seismic waves
|
|
|
modified mercalli scale
|
rates the types of damage and other effects of an earthquake (intensity of an earthquake)
|
roman numerals 1-12
|
|
|
epicenter intensity
|
highest usually
|
|
|
|
earthquAke classification
|
shallow, intermediate, deep depending on quakes focus
|
|
|
|
epicenter distAnce
|
measuring p wave and s wave separation
|
|
|
|
time of an earthquake
|
subtracting the Appropiate travel time from the known arrival time of the wave
|
|
|
|
EArthquake association
|
with tectonic plate boundaries 80% of all quakes occur in circum pacific belt
|
|
|
|
seismic wave
|
greater intensity in soft ground akA soil
|
|
|
|
fault scarps
|
areas of great vertical offset where the fault interests ground surface
|
|
|
|
seismic gaps
|
sections of active faults that haven't experienced earthquakes for a long period of time
|
|
|
|
seismology
|
studie of earthquAkes
|
|
|
|
sensitive instruments that detect earthquAkes
|
seismogrAphs, seismometers
|
|
|
|
seismogram
|
the record produced by a seismometer
|
|
|
|
p waves
|
when strike core, refracted so beyond a distance of 11000 km from epicenter they disappear and reemerge at 16000
|
|
|
|
p wave shadow
|
the area that doesnt get p waves
|
|
|
|
s waves
|
do not go through liquids
|
|
|
|
lithosphere
|
mAde of igneous rocks, granite, basAlt, and peridotite
|
|
|
|
asthenosphere
|
peridotite
|
|
|
|
lower mantle
|
simple oxides
|
|
|
|
core
|
iron and nickel
|
|
|
|
compressive
|
convergent
|
|
|
|
tensional
|
divergent
|
|
|
|
shear
|
transform
|
|
