Global Hazard Patterns

Question 1

name 3 geophysical hazards

Answer 1

earthquakes, tsunamis, volcanoes

Question 2

which plate boundaries trigger earthquakes?

Answer 2

conservative & destructive

Question 3

how to destructive plate boundaries cause earthquakes?

Answer 3

1. plates move toward/ together
2. force of compression
3. stresses in crust
4. pressure quickly released
5. earthquake focus

Question 4

how do conservative plate boundaries cause earthquakes & give an example of one

Answer 4

1. plates slide past each other
2. friction & quick releases of tension
3. frequent shallow earthquakes
   San Andreas Fault

Question 5

explain the difference between the lithosphere and the asthenosphere

Answer 5

lith = crust
asthen = molten zone of rock beneath crust

Question 6

what 2 main primary hazards do earthquakes cause?

Answer 6

1. buildings collapse

2. water pipes burst

Question 7

what 3 main secondary hazards are caused by earthquakes?

Answer 7

1. tsunamis
2. landslides
3. soil liquefaction

Question 8

what plate boundaries are volcanoes found on

Answer 8

destructive & constructive & hotspots

Question 9

give an example of a volcanic destructive plate boundary

Answer 9

ring of fire, pacific ocean

Question 10

give an example of a volcanic constructive plate boundary

Answer 10

ocean mid-atlantic ridge (iceland)

Question 11

how does a hotspot create volcanoes & give an example

Answer 11

areas of lithosphere receiving abnormally high heat from aesthenosphere, hawaii island

Question 12

what is drought dependant on in africa?

Answer 12

inter-tropical convergence zone, if north to south direction disrupted, then food security threatened from drought in Somalia/Ethiopia

Question 13

what causes drought in australia?

Answer 13

el nino

Question 14

where does flooding usually occur?

Answer 14

in areas of excessive, monsoon rainfall & cyclones (e.g hawaii in el nino), or where snow melting on mountains adds to swollen river system

Question 15

where does el nino cause flooding & what is its impact?

Answer 15

• south america

- flooding = disease, destruction infrastructure, insurance costs

Question 16

where do tropical cyclones usually occur, give example?

Answer 16

• over warm water, 5degrees North or South of equator, Coriolis effect causes circulation of air
• off coast of east asia

Question 17

how does the philippines geophysical location make it vulnerable to multiple hazards?

Answer 17

• lies within SE Asian typhoon belt
• destructive plate boundary, philippines plate subducting under eurasian plate
• N & E coast faces Pacific ocean
• monsoon climate = flooding
• 7000 islands = difficult to reach & warn

Question 18

what 4 human factors mean the philippines is vulnerable to the multiple hazards it faces?

Answer 18

1. MIC = 2006, GDP: $5000 per capita
2. poor people live in high risk coastal areas, exposed to storm surges
3. pop density, 2000 per km in Manila, which is at sea-level
4. pop growth, 250 000per year in Manila

Question 19

when did Mt. Pinatubo erupt?

Answer 19

1991

Question 20

why was the explosion of Mt. Pinatubo so large (5 steps)?

Answer 20

1. Philippines plate subducts & melts
2. melted magma forms magma chamber
3. magma solidifies = solid cap over volcano vent
4. pressure builds under cap
5. cap ruptures = huge pyroclastic flows & lahars

Question 21

how many died from the eruption of Mt. Pinatubo?

Answer 21

350

Question 22

how many were evacuated by US air base before Mt. Pinatubo eruption?

Answer 22

200, 000, although many died after from disease in camps

Question 23

how many hectares of farmland were destroyed by Mt. Pinatubo eruption in 1991?

Answer 23

80, 000 hectares

Question 24

what other hazard does the philippines face? Give an example

Answer 24

landslides, Guinsaugon landslide 2006, killed 1150

Question 25

what triggered the landslide in the philippines in 2006?

Answer 25

2.6 earthquake

Question 26

give 1 human and physical factor that exacerbated the guinsaugon landslide in the philippines?

Answer 26

human = deforestation, shallow rooted coconut trees, mass movement
physical = la nina, caused heavy rain in usually dry month of feb

Question 27

what plate boundary is the san andreas fault in california?

Answer 27

conservative, slide past each other at different speeds

Question 28

how many people densely live in california?

Answer 28

40 million

Question 29

how many major earthquakes have occurred in the last 100 years in Cali?

Answer 29

5

Question 30

in what year did the 7.9 earthquake take place in San Francisco?

Answer 30

1989

Question 31

how much cost of damage was caused by the 1989 san francisco earthquake?

Answer 31

$6 billion!

Question 32

how many homes were destroyed in the san francisco earthquake?

Answer 32

1018 destroyed!

Question 33

in what year was the 6.7 earthquake in LA?

Answer 33

1994

Question 34

how many homes were impacted in the Northridge LA earthquake?

Answer 34

9000 homes without water

Question 35

which rivers are affected by el nino in california?

Answer 35

san gabriel rivers, hillsides deforested so heavy rainfall easy surface run-off

Question 36

why do la nina droughts cause so many problems for california?

Answer 36

• forest fires mean no trees to protect against rainfall in el nino = landslides
• mediterranean climate is hot already without droughts in summer

Question 37

how is advection fog caused & impacts california

Answer 37

• cold air offshore meets hot air onshore
• combines with car pollution
• photochemical smog
• sits in basin of california