Landslides 1

Question 1

What is mass wasting?

Answer 1

used by farmers when landslide wreck the land / crops

Question 2

Why are reported landslide fatalities (wrongfully) low?

Answer 2

most fatalities are associated with the trigger (EQ, flood, etc) and not the landslide itself

Question 3

Turtle Mountain

Answer 3

“Mountain that walks”
ex/ Frank Slide, Alberta

Question 4

Why are some landslides more deadly?

Answer 4

had higher vulnerability / people in the way

ex/ Peru (less rock but had ppl) vs Pemberton (more rock but no ppl)

Question 5

Human and economic impacts of landslides are broadly governed by?

Answer 5

• population density
• cost of infrastructure
• population preparedness

Question 6

How often does a landslide occur?

Answer 6

everyday!
-> some piece falls off

Question 7

How often does a landslide occurs that closes a highway?

Answer 7

probably 1-10 yrs
ex/ porteau cove rockslide

Question 8

Why is Japan much more affected by landslides?

Answer 8

higher population density

~200 lives/yr whereas in Canada it’s ~3 lives/yr

Question 9

Economic impacts of landslides

Answer 9

impossible to determine

estimates:
Canada ~$1.4 billion/yr
US ~$3.5 billion/yr
Japan ~$4 billion/yr
Venezuela ~$62 Million /yr
(cost of rebuilding is less)

Question 10

Landslides are considered more fatal when

Answer 10

there is more people affected

Question 11

What are some causes of landslides?

Answer 11

mountains
rain
EQ
ice thawing

Question 12

Classify landslides based on

Answer 12

1. type of material
2. type of motion
3. rate of movement

Question 13

Type of materials

Answer 13

• rock
• soil
• mud
• debris (combo of rock, trees, water, stuff)

Question 14

Type of motions

Answer 14

• falls
• slides
• flows
• complex movements

Question 15

What is a slide?

Answer 15

• material moves as a coherent mass along a surface of failure
• vary from slow to fast
• usually soil, rock, debris

Question 16

Rotational slide / slump

Answer 16

• rotation of material on a curved failure surface
• intermediate speed
• usually weak material
• often a curved scarp above slide

Question 17

Translational slide

Answer 17

like a kid down a slide
- cohesive motion of material along a flat failure surface
- slow to fast
- usually strong material moving on planes of weakness

Question 18

If a slide moves slowly, what do we call it?

Answer 18

• creep
• soil flow
• earth flow

Question 19

what is a flow?

Answer 19

• like fluid, moves independently around stuff (chaotic)
• very slow to very fast
• soil, mud, WET debris
• water very important

Question 20

what is a fall?

Answer 20

• occur on very steep slopes
• usually rock
• material detaches cuz weakness / fractures
• falls cuz gravity, very fast

Question 21

What is a scarp?

Answer 21

Above the slide, part where it breaks off
-> NOT to be confused with failure surface!

Question 22

What are complex movements?

Answer 22

combo of the mass movements
ex/ slide that becomes a fall