EOSC 114: EARTHQUAKES EXAM WITH
COMPLETE SOLUTIONS
earthquakes... - ANSWER- associated with rupture of a fault
accumulated stress released as seismic energy
seismic waves radiate
causes shaking
3 types of stress - ANSWER- COMPRESSION -- convergent
forces opposite
towards each other
TENSION -- divergent
forces opposite
opposite direction from each other
SHEAR/TRANSVERSE -- transform
forces opposite
parallel across a plane
3 types of strain - ANSWER- STRAIN is DEFORMATION -- under stress
ELASTIC: temporary, reversible
DUCTILE: plastic flow, permanent
BRITTLE: breaks, permanent
controlled by:
temperature, pressure, speed, duration
depends on:
how it's applied, temperature, material properties
faults - ANSWER- FAULT: large brittle fracture
, -- point of origin for most earthquakes
hanging wall -- above fault
foot wall -- below fault
normal - ANSWER- divergent - tension - weakest
blocks move away from each other
hanging wall moves DOWN relative to footwall
caused by tension
shallow foci -- thin crust
reverse/thrust - ANSWER- convergent, compression, strongest
blocks move towards each other
hanging wall moves UP -- gets smaller & push
compression -- shortening and thickening
low angle thrust
shallow to deep foci
transverse/strike-slip - ANSWER- transform, shear, moderate
lateral, not vertical (like traffic on a highway)
horizontal motion
no extension/shortening
shallow foci
global distribution of earthquakes - ANSWER- along plate boundaries / fault lines
frequency decreases with magnitude
which faults are most common at which types of plate boundary - ANSWER-
CONVERGENT: subduction/collision, reverse/thrust fault
force: compression
deep, m8-9.7, infrequent, plate interface, overriding plate, depends on
vulnerability
DIVERGENT: normal fault
force: tension
shallow (<30km), m6, frequent lil quakes, mid ocean, low risk
TRANSFORM: strike slip
COMPLETE SOLUTIONS
earthquakes... - ANSWER- associated with rupture of a fault
accumulated stress released as seismic energy
seismic waves radiate
causes shaking
3 types of stress - ANSWER- COMPRESSION -- convergent
forces opposite
towards each other
TENSION -- divergent
forces opposite
opposite direction from each other
SHEAR/TRANSVERSE -- transform
forces opposite
parallel across a plane
3 types of strain - ANSWER- STRAIN is DEFORMATION -- under stress
ELASTIC: temporary, reversible
DUCTILE: plastic flow, permanent
BRITTLE: breaks, permanent
controlled by:
temperature, pressure, speed, duration
depends on:
how it's applied, temperature, material properties
faults - ANSWER- FAULT: large brittle fracture
, -- point of origin for most earthquakes
hanging wall -- above fault
foot wall -- below fault
normal - ANSWER- divergent - tension - weakest
blocks move away from each other
hanging wall moves DOWN relative to footwall
caused by tension
shallow foci -- thin crust
reverse/thrust - ANSWER- convergent, compression, strongest
blocks move towards each other
hanging wall moves UP -- gets smaller & push
compression -- shortening and thickening
low angle thrust
shallow to deep foci
transverse/strike-slip - ANSWER- transform, shear, moderate
lateral, not vertical (like traffic on a highway)
horizontal motion
no extension/shortening
shallow foci
global distribution of earthquakes - ANSWER- along plate boundaries / fault lines
frequency decreases with magnitude
which faults are most common at which types of plate boundary - ANSWER-
CONVERGENT: subduction/collision, reverse/thrust fault
force: compression
deep, m8-9.7, infrequent, plate interface, overriding plate, depends on
vulnerability
DIVERGENT: normal fault
force: tension
shallow (<30km), m6, frequent lil quakes, mid ocean, low risk
TRANSFORM: strike slip
