Studying for the exam

Question 1

what are the global trends of natural disasters (4 things)

Answer 1

• the number of great natural disasters is increasing
• population is becoming increasingly vulnerable
• number of man made disasters is decreasing
• economic losses from natural disasters are increasing with time

Question 2

what is the formula for risk

Answer 2

• risk = vulnerability x hazard

Question 3

4 (but really 5) pillars of emergency management

Answer 3

• response
• recovery
• mitigation
• preparedness
• adaptation

Question 4

what is the crust made of

Answer 4

• silicon and oxygen

Question 5

what is the mantle made of

Answer 5

• iron and magnesium

Question 6

what is the outer and inner core made of

Answer 6

• outer core: liquid iron
• inner core: solid iron

Question 7

what are the orders of layers of the earth based on strength (7)

Answer 7

• atmosphere (gas)
• liquid hydrosphere (ocean)
• rigid lithosphere (mantle)
• soft plastic asthenosphere (lower mantle)
• stiff plastic mesosphere (lowest mantle)
• liquid outer core
• solid inner core

Question 8

what causes the internal geomagnetic field

Answer 8

• due to the liquid iron in the outer core
• sometimes ends of the polar magnetization switch

Question 9

ocean curst is never older than

Answer 9

• 200 ma because it is always being recycled

Question 10

bathymetry

Answer 10

• depth of the ocean measured at different locations

Question 11

differences between shallow, intermediate and deep earthquakes

Answer 11

• shallow: <100km
• intermediate: 100-300km
• deep: 300-700 km

Question 12

Mercalli intensity scale

Answer 12

• based on eyewitnesses and damage to the surface
• not super accurate and consistent

Question 13

frequency of soil vs hard rock

Answer 13

• soil = <1Hx
• hard rock = >1Hz

Question 14

liquefaction

Answer 14

• strength of the soil is reduced by rapid and violent shaking or loading
• occurs in saturated soils in which the space between articles is filled with water
• low pore pressure = strong binding force

Question 15

what is the flexibility of buildings

Answer 15

• 10 Hz per number of storeys

Question 16

what is building resonance

Answer 16

• the number of seconds it takes of the building to anturally vibrate back and forth

Question 17

body waves, p waves, s waves and surface waves

Answer 17

• body waves:
  - propagate through the whole body of the earth
  - large earthquakes generate body waves recorded all over the world
• P waves:
  - primary waves
  - compressional energy
  - small amplitude
  - travel faster and therefore arrive first
  - faster in water and slower in hard rock
• S waves
  - secondary waves
  - shear energy
  - larger amplitude
  - don’t travel as fast
• surface waves
  - low frequency
  - slow velocity
  - very large amplitude

Question 18

intrusive igneous rocks

Answer 18

• cooling at depth
• slow cooling
• large grains

Question 19

extrusive igneous rocks

Answer 19

• cooling at the surface
• fast cooling
• small grains
• contact with the atmosphere or water

Question 20

low vs high viscosity magma

Answer 20

• low:
• tends to reach the earth’s surface
• erupts peacefully
• basaltic magma
• high temperature
• low volatile content
• lower SiO2 content
• flows quickly
• high:
• tends to form intrusive bodies
• erupts explosively
• andesitic and rhyolitic magma
• low temperature
• high volatile content
• higher SiO2 content
• flows slowly

Question 21

Volatiles

Answer 21

• H2O
• CO2
• SO2

Question 22

pyroclastic material

Answer 22

• classified according to particle size
• ash = <2 mm
• Lapilli = 2-64 mm
• Scoria = >64 mm

Question 23

features of divergent zone volcanoes

Answer 23

• formation of new oceanic crust
• peaceful eruptions: low pressire, rock melts partially, magma rises and flows
• like iceland

Question 24

features of subduction zone volcanoes

Answer 24

• H2O from subducting plate lowers the melting point of rock
• partial melting is induced in the overriding plate
• magma rises and erupts
• potentially explosive eruptions
• low temperature and high SiO2 = high viscosity
• at ocean - continent there is more SiO2 and at ocean - ocean there is less SiO2
• example mt st helens

Question 25

features of hot spots

Answer 25

- peaceful eruptions - low viscosity and low volatile content and low SiO2

Question 26

minimum earthquake for a tsunami to occur

Answer 26

- >7.5 with epicenters underwater

Question 27

shoaling

Answer 27

- occurs when waves interact with the seafloor near the shoreline - interaction starts when depth is less than 2 m - friction slows wave down therefore increasing amplitude

Question 28

size of tsunami waves

Answer 28

- amplitude is 6-15 m - period is 10-60 minutes - second or third wave is the largest - length can be 100 km

Question 29

greenhouse effect

Answer 29

- the lower atmosphere absorb and reradiate the energy to the earth - water vapor (the most abundant gas) - CO2 - methane

Question 30

coriolis effect

Answer 30

- circulation of wind through the earth - forces imposed by the earht's rotation - the force responsible for transporting the energy stored in water around the world (through wind)

Question 31

Pyrolysis

Answer 31

- input: wood material heated above initiation temperature - output: flammable hydrocarbon vapors; water vapor, tar, mineral residue