Lecture #9 [Earthquakes-Mass Wasting]

Question 1

Faulting

Answer 1

lithospheric plates moving past one another, slowed by friction, rocks along boundary undergo stress/strain
when stress overcomes strength rocks rupture along a fault

Question 2

Focus

Answer 2

point of initial rupture within earth

Question 3

Epicenter

Answer 3

place on surface directly above focus

Question 4

Earthquake magnitude

Answer 4

moment magnitude (originally richter scale)
determined from rigidity of rocks,the are that ruptured along fault plane and amount of movement along the fault

Question 5

Earthquake intensity

Answer 5

10 categories to examine

relies on how people percieve the shaking and the extent of the damge to buildings

Question 6

which plates are we dealing with in the PNW

Answer 6

juan de fuca and north american potential cascadian subduction zone “megathrust” earthquake

Question 7

Mass wasting

Answer 7

downslope movement of earth materials, “landslides” major types of mass wasting in BC: falls,flows,slides

Question 8

Falls

Answer 8

at the base of most cliffs theres an accumulation of fallen material known as talus or scree

Question 9

Rock avalanche

Answer 9

a massive rock fall explodes apart on contact with a slope, thousands of rocks flying downslope. Transitional: changes to rapid flow of material beyond base of slope

Question 10

Slides

Answer 10

material slips over one or more surfaces

wet tectonically active earthquake prone areas

Question 11

Flows

Answer 11

internal movement of individual grains within flow

Question 12

variables in mass wasting

Answer 12

earth material type
slope angle and topography
climate
veg
water
time