Hazardous Environments Flashcards
1
Q
Formation of an earthquake
A
- convection current in the mantle
- plates move
- at plate margins
- plates catch on each other
- pressure builds up
- sudden release = seismic waves
2
Q
What do you use to measure an earthquake
A
A seismometer
3
Q
What scale do you use to measure earthquakes
A
Richter scale
4
Q
Where is the epicentre
A
The place directly above the focus on the crust
5
Q
What happens every time a Richter scale goes up by one
A
x10 from the previous number
6
Q
What type of scale is the Richter scale
A
Logarithmic scale (log)
7
Q
What effects the amount of damage caused by the Richter scale
A
The vulnerability
8
Q
What does the Modified Mercalli intensity scale do
A
Deals with the amount of damage that will be caused
9
Q
What does the Richter scale do
A
Measure strength of the earthquake
10
Q
What are the two scales used to measure earthquakes
A
- Richter scale
- modified Mecalli intensity scale
11
Q
What is a primary wave
A
- can be detected
- fast travelling
12
Q
What is a secondary wave
A
13
Q
Reasons people live in hazardous environments
A
- fertile soil
- ignorance
- dont think it will happen in their life
- tourism
14
Q
What is a hazard
A
An event that threatens or actually causes damage and destruction to people, their properties and settlements
15
Q
Examples of natural disasters
A
- storms
- floods
- earthquakes
- volcanic eruptions
16
Q
Why are some places more hazardous
A
- experience more than one type of natural hazard event
- experience natural hazards more frequently than others
- hazards are stronger and more destruction than in others
- better able to cope with the damaging impacts of natural hazards
17
Q
Types of geological hazards
A
- earthquake
- volcanic eruptions
- landslides
18
Q
Type of climatic hazards
A
- storms
- floods
- drought
19
Q
Types of biological hazards
A
- fires
- pests
- diseases
20
Q
Types of technological hazards
A
- nuclear explosions
- transport accidents
- pollution
21
Q
What is used to measure hurricanes
A
Saffir-Simpson scale
22
Q
What is a hazard
A
An event that threatens or actually causes damage and destruction to people, their property and settlements
23
Q
What is a natural hazard
A
Produced by environmental processes
- storms
- floods
- earthquakes
- volcanic eruptions
24
Q
Reasons places are more hazardous
A
- experience more than one type of hazard
- experience them more frequently
- more strong and destructive
- better able to cope with the impacts
25
What is the formation of a cyclone/hurricane
- when 2 air masses meet
- ocean temp is greater than 27 C (not too hot)
- sea at its warmest (dec/jan in southern. June in northern)
- move from east to west
- water vapour in the air condenses to make clouds
26
What is the Coriolis force
- happens as the earth rotates
- northern hemisphere: air move from high to low pressure. Air goes to the right
- Southern Hemisphere: air moves from low to high pressure. Air goes to the left
27
Where are tropical cyclones found
- in between the tropics
| - not on the equator
28
What are tropical cyclones
- areas of very low air pressure
- often 600-750 km across
- torrential rain
- thunder and lightning
- very strong winds
29
What causes damage from cyclones
- very strong winds: damage
- torrential rain: flooding, landslides, mud
- storm surges: sea level rise, floods
30
How are volcanoes formed
- destructive plate margin
- oceanic plate travels beneath continental plate
- plate starts to melt called subduction
- molten rock rises to surface to form a volcano
- (friction causes an earthquake)
31
What is a hotspot
A concentration of heat/radioactive decay
32
Examples of hotspots
Hawaii was formed by hotspots
33
Distribution of volcanoes and earthquakes
Along tectonic plates
34
Characteristics of a volcano
- lava flows
- ash
- gas emissions
35
What is a pyroclastic flow
Fast moving current of gas and volcanic matter
36
Characteristics of earthquakes
- sudden and brief period of intense shaking of the ground
37
What is the focus
The center of the earthquake underground
38
What is the epicenter
The point on the surface directly above the focus
39
What effects the amount of damage caused by an earthquake
- depth of the focus
| - type of rock
40
What do shock waves do to rocks
Liquify them
41
Secondary impacts of earthquakes
- fires due to ruptured gas mains
- tsunamis
- aftershocks
42
What is used to measure volcanoes
Volcanic explosivity index (VEI)
43
What is the VEI
- logarithmic scale
- measures the volume of gas ejected
- measures the height the gas reaches into the atmosphere
44
Problem with the VEI
Only suitable for one type of volcanic eruption
45
Factors that effect the damage caused by a natural disaster
- size of area affected
- density of population affected
- how long it lasts for
- how much warning people get in advance
- how prepared people are
- the countries ability to cope
46
Primary impacts of earthquakes
- collapsed buildings
- broken water, gas pipelines
- electric power lines down
47
Primary impacts of volcanoes
- buildings, roads and crops destroyed by lava flow
- death and injury from lava, ash and gas
- contamination of water
48
Secondary impacts of volcanoes
- lahars created
- fires
- psychological trauma
49
What is a lahar
Mix of ash and mud with rainwater/melting snow
50
Reasons someone would live in a high risk area
- lack of education
- aware but still choose to live there
- unable to move away
- dont think it will happen to them
- have lived there their whole life
- minerals
- fertile soil
- geothermal energy
- tourism
51
Short term impacts of cyclones
- damage to property (high winds)
- people killed or injured
- disruption of businesses
- landslides
- flooding
- soil erosion
52
Ways to reduce the impacts of a hazardous event
- know when and where the hazard will happen (prediction)
| - take precautions before the event happens (preparation)
53
Sequence of steps to manage natural hazards
- identify natural hazard threats
- risk assessment
- prediction
- preparation
- HAZARD EVENT
- recovery
- appraisal (know what needs to be improved)
54
What is a risk
The probability of a particular event happening and the scale of its possible damage
55
Things you need to know in order to access a hazards risk
- distribution
- frequency
- scale
- predictability
56
Ways to predict hazards
- weather stations
- weather satellites
- radar
57
Ways to prepare for hazards
- building design
- location of settlements
- warning systems
- education
58
Ways to respond to hazards
- releases people/bodies trapped
- use lifting gear
- restore basic derives (water, sewage, gas, electricity, communications)
- providing medical help
- temporary shelters
- transport for emergency suplies
59
Long term planning questions
- do the risks need to be reassessed
- do the warning systems need to be improved
- are the evacuation procedures adequate
- can delivery for emergency aid be improved
- can buildings be made better
- are maps or hazards up to date
- should settlement be relocated
- is the rebuilding program fit for purpose
60
What affects the speed and direction the waves travel
The layers of the earth
61
What is the outer core made out of
It is a liquid
- iron
- nickle
62
What is the inner core made of
It is a solid
- iron
- nickel
63
Why is the core still hot
Atomic decay
64
What is convection current
- magma rises from heat of the core: less dense
| - then cools down and falls: more dense
65
Cyclone impacts
Physical: damage to property. High winds, rain
Social: number of people killed or injured
Economic: businesses, transport, services
Environmental: landslides, erosion, flooding
66
What is a constructive plate boundary
- divergent plate boundary
| - where two plates are moving apart
67
What are destructive plate boundaries
- collision plate boundaries
| - where the plates are moving together
68
What are conservative plate boundaries
- transform plate boundaries
| - when the plates are sliding past eachother
69
What model shows how a country recovers from a hazard
The parts model
70
What is wind shear
Sudden change in direction of wind
71
What are the characteristics of the eye of a hurricane
Low pressure and low wind speed
