Geologic Hazards

Question 1

why do earthquakes form?

Answer 1

sudden movement of plate causes rock to break at the hypocenter and release energy in the form of seismic waves. Waves spread from the epicenter

Question 2

Difference between focus and epicenter

Answer 2

Focus or hypocenter is the origin of the earthquake at depth while epicenter is the point at the surface directly above the hypocenter

Question 3

Elastic rebound theory

Answer 3

Original position - buildup of strain - rupture/slippage - release of energy

Question 4

Def
Seismic waves
body waves
surface waves

Answer 4

seismic waves - form of propagation of energy released in an earthquake
body waves - emanate from the focus in all directions through the interior of earth
surface waves - travels at earth’s surface

Question 5

cc
Seismic waves
body waves
surface waves

Answer 5

body waves 
primary - push pull (solid and liquid)
secondary - transverse (up/down) solid only
surface waves
rayleigh - cyclical up and down
love - cyclical side to side

Question 6

Difference between seismograph and seismogram

Answer 6

seismograph - instrument

seismogram - graph

Question 7

difference between magnitude and intensity

Answer 7

magnitude - amount of energy released by the earthquake

intensity - strength felt by people/destruction or damage caused by the earthquake

Question 8

how to locate earthquake

Answer 8

measure S-P interval, determine distance, determie magnitude by measuring amplitude, locate the epicenter

Question 9

Factors promoting mass wasting:

ssg

Answer 9

slope, soil cover, geologic feature
slope:
g(to downslope) > g (stay in place)
geologic feature:
Type of rock; presence of joints, fractures, or bedding planes
Dips upslope, horizontal, dips downslope

Question 10

If direction of slope is the same as direction of *: daylighting slope

Answer 10

planar features

Question 11

Types of mass wasting

Answer 11

Fall, topple
Slide, Slump
Flow
Granular flow (debris avalanche, earthflow, creep) and slurry flow

Question 12

sudden movement of rock, separated along fractures or bedding planes no fluidity in the motion, only bouncing, rolling and free fall

Answer 12

Fall

Question 13

blocks of material fall over as a unit, similar to falling dominos

Answer 13

Topple

Question 14

result when rocks and debris slide down a pre-existing surface, such as a bedding plane, foliation surface, or joint

Answer 14

Slides (Translational)

Question 15

downward rotation of rock or regolith occurs along a concave-upward curved surface leave arcuate scars or depressions on the hill slope

Answer 15

Slumps (Rotational slides)

Question 16

creep + water

Answer 16

solifluction