The Challenges of Natural Hazards Flashcards
(94 cards)
1
Q
What is a natural hazard?
A
A natural event that threatens people or has the potential to cause damage, destruction, and death
2
Q
What is a natural disaster?
A
A natural hazard that has happened
3
Q
What are the two types of natural hazards, and give examples.
A
Geological (caused by tectonic plates movement)
eg. earthquakes, volcanoes, avalanches
Meteorological (involving weather, atmosphere and climate)
eg. heatwaves, hurricanes or bushfires
4
Q
What are 3 factors that affect how bad a natural hazard is?
A
- Frequency
- Magnitude
- Predictability
5
Q
What are risks of a natural disaster?
A
- opulation density
- ability to cope/deal with events
- money for protection
- risk of area
6
Q
Why do people live in high risk areas?
A
- can’t predict magnitude, timing or location
- can’t move due to expenses, language barrier, or knowledge
- worth staying for resources, jobs and prices
- don’t want to go as they’re optimistic/overconfident
7
Q
What are the 3 layers of earth?
(inside to out)
A
- Inner metallic core (solid) = hottest part
- Outer core (liquid)
- Mantle = semi-molten rock
- Crust = very thin and broken into large pieces called tectonic plates
8
Q
What is the lithosphere?
A
The rigid outer layer of the Earth, made up of the crust and the uppermost part of the mantle
9
Q
Describe the oceanic plate.
A
- thin (5-10km)
- dense
- young (less than 200 million years old)
- sinks when with continental
- recycled at destructive margins
10
Q
Describe the continental plate.
A
- thick (20-200km)
- less dense
- up to 3.8 billion years old
- granite rock
- not destroyed
11
Q
What is a plate margin/boundary?
A
Location on Earth where 2 tectonic plates meeet or are next to each other
12
Q
What is convection current?
A
- the cyclical movement of fluids caused by temperature and density differences
- happens in upper mantle, the heated molten rock rises and hits the underside of the plate, dragging the tectonic plates
13
Q
What happens at a constructive plate margin?
A
PLATES MOVE APART
- this causes a gap where magma rises up to fill the gap, this cools to form solid rock
- forming part of the oceanic plate.
- magma can also form a shield volcano
14
Q
What happens at a destructive plate margin?
(oceanic + continental)
A
PLATES MOVE TOWARDS EACH OTHER
- oceanic plate slides beneath continental (subduction zone)
- rocks get stuck on each other and pressure builds up, oceanic plate melts and magma can escape through a composite volcano
-until they slip past each other
15
Q
What happens at a destructive plate margin?
(continental + continental)
A
PLATES MOVE TOWARDS EACH OTHER
- two continental plates form fold mountains
- pressure builds up
- until they slip past each other
16
Q
What happens at a conservative plate margin?
A
PLATES SLIDE PAST EACH OTHER
- they get stuck and friction/pressure builds up
- until they slip past each other
17
Q
Which plates margins cause volcanic eruptions?
A
Constructive and destructive (o+c)
18
Q
Which plates margins cause earthquakes?
A
ALL (constructive is weak)
19
Q
What is a hotspot?
A
Hotspots are places where the magma rises up through the crust
20
Q
What is the ring of fire?
A
The ‘ring of fire’ is a group of volcanoes that are located along the plate margin of the Pacific plate
21
Q
What 4 things do volcanos produce?
A
- Pyroclastic flows (superheated lava, gas and ash moving 500km/h)
- Ash (burnt rock fragments)
- Gases (like sulfur)
- Lava (magma at surface)
22
Q
What are primary effects of volcanic activity?
A
- crop/livestock death
- human deaths
- damaged building/houses
- cause suffocation
- ash everywhere
- pyroclastic flows
- lahars (mud flows of water + ash)
23
Q
What are secondary effects of volcanic activity?
A
- famine/starvation
- decreasing population
- homelessness
- disrupting local economy + tourism
- increased soil fertility + volcanic winter
24
Q
What are immediate responses for volcanic activity?
A
- warnings and monitoring
- aids, charities and donations
- temporary infrastructure providing shelter, food, water, electricity
- rescued people
25
What are long-term responses for volcanic activity
- improve local economy by encouraging tourists
- relocation, resettlement programs
- rebuilding infrastructure, transport, power and homes
26
What are the 3 aspects of an earthquake?
1. Focus = where pressure is released
2. Shock waves = most damage, aka seismic waves
3. Epicentre = point directly above the centre of earthquake
27
What is the magnitude scale?
How much energy it releases, the richter scale is logarithmic (goes up in tens)
28
What are primary effects of earthquakes?
- ground shaking, buildings collapse
- ground rupture (split)
- injuries, deaths
- infrastructure damage
29
What are secondary effects of earthquakes?
- water contamination, diseases (cholera)
- power outages
- tsunamis/landslides
- economic loss
- fires
30
What are immediate responses for earthquakes?
- rescue operations
- dead bodies disposed to prevent diseases
- aid, charities, donations
- temporary infrastructure, providing shelter, food, water etc
- evacuation/warnings
31
What are long-term responses for earthquakes?
- improved preparation to withstand future earthquakes
- improve local economy by encouraging tourists
- rebuild infrastructure
32
When and where did the Chile earthquake occur?
February 2010, on the coast
33
What was the magnitude of the Chile earthquake?
8.8 on the Richter scale
34
What were the primary effects of the Chile earthquake?
- 500 killed
-12,000 injured
- 220,000 homes destroyed
- $30 billion damage.
35
What were the secondary effects of the Chile earthquake?
1500km of roads damaged by landslides, tsunami caused coastal flooding.
36
What were the immediate responses to the Chile earthquake?
- emergency services acted quickly
- international help provided field hospitals
- temporary repairs to highway
37
What were the long-term responses to the Chile earthquake?
- government launched housing reconstruction plan
- economy rebuilt without much foreign aid
38
When and where did the Nepal earthquake occur?
April 2015, near Kathmandu, Nepal.
39
What was the magnitude of the Nepal earthquake?
7.9 on the Richter scale
40
What were the primary effects of the Nepal earthquake?
- 9000 killed
- 20,000 injured
- 8 million affected
- $5 billion damage (over 50% of shops and homes destroyed)
41
What were the secondary effects of the Nepal earthquake?
- Avalanches on Mount Everest killed 19
- landslides blocked roads
- shortage of water and electricity
42
What were the immediate responses to the Nepal earthquake?
- Search and rescue teams
- international aid and helicopters
- half a million tents provided.
43
What were the long-term responses to the Nepal earthquake?
- Roads repaired
- over 7000 schools rebuilt
- stricter building codes enforced.
44
Compare the primary effects of the Chile and Nepal earthquakes.
Chile: 500 deaths, $30bn damage. Nepal: 9000 deaths, $5bn damage.
45
Compare the secondary effects of the Chile and Nepal earthquakes.
Chile: Tsunami and landslides. Nepal: Avalanches, landslides, and blocked roads.
46
Compare the immediate responses of the Chile and Nepal earthquakes.
Chile: Quick emergency response, major highways repaired. Nepal: International aid, tents, and helicopters.
47
Compare the long-term responses of the Chile and Nepal earthquakes.
Chile: Strong economy allowed independent rebuilding. Nepal: Relied on international aid, building codes improved.
48
What are the 4 things to reduce the impact of tectonic hazards?
1. Monitoring
2. Predicting
3. Protection
4. Planning
49
Give examples of Monitoring.
- using seismometers to detect movement (saving lives)
- monitoring volcanos is easier because of the oozing, gas emissions and magma
50
Give examples of Predicting.
- looking at tectonic plate boundaries to know where they're likely
- difficult to predrict
51
Give examples of Protecting.
- HIC's can invest in earthquake-proof buildings, fire resistant materials and shock absorbers to reduce damage
- LIC's use a lighter roof material (bamboo) to reduce damage if collapsed
- automatic switches turn off electricity/gas
- drills to education people
52
Give examples of Planning.
- HIC's have warning systems and evacuation plans
- police, paramedics and firefighters trained
- governments can stockpile supplies and education people
53
Why do people still live in areas of risk?
- fertile land, good for farming and producing high yield
- good government, good evacuation/regulations
- family in area
- jobs/cost
- unaware of risks
54
How are winds caused?
The difference in air pressure, caused by convection currents (different temperatures)
55
Where do winds move?
High pressure areas to low pressure areas
56
Winds combine to form global atmospheric circulation cells, what are they made up of?
1. cool sinking air (forming high pressure belts)
2. warm rising air (forming low pressure belts)
57
How many global atmospheric circulation cells are there in each hemisphere, what are the names?
3 cells;
-Hadley
-Ferrel
-Polar
58
1. Earths surface is warned by the ____ at the equator, earth transmits this heat to nearby air which gets hotter and _____, forming a ____ pressure belt. It then cools with water vapour condensing, creating ___ and clouds. The rising air cools and moves ___ from the equator towards _____ north and south.
Earths surface is warned by the SUN at the equator, earth transmits this heat to nearby air which gets hotter and RISES, forming a LOW pressure belt. It then cools with water vapour condensing, creating RAIN and clouds. The rising air cools and moves AWAY from the equator towards 30° north and south.
59
What happens at 30° north and south?
- air is further away from the equator, cool air falls
- resulting in high pressure belt with minimal rainfall and no clouds
- the cool air reaches earth and surface winds blow them towards the equator or the poles
60
What happens at 60° north and south?
- cold air blown from the poles meets warm air surface winds, because warm air is less dense
- it rises and forms low pressure belt
- some return back towards the equator, rest head towards the poles
61
What happens at the north and south pole?
-cool air sinks forming a high pressure belt, moving back to the equator as surface winds
62
1. Where do trade winds move from/to?
2. Where do westerlies move from/to?
3. Where do polar easterlies move from/to?
1. 30° north/south towards the equator
2. 30° north/south towards 60°
3. 60° north/south towards the poles (90°)
63
What is the Coriolis effect?
The earths surface rotates faster at the equator than poles, causing the winds to move in a curved line.
64
To summarise;
sinking air = ___ pressure, ___ clouds/rain
rising air = ___ pressure, ___ clouds/rain
sinking air = high pressure, no clouds/rain
rising air = low pressure, has clouds/rain
65
To summarise;
Poles =
60° north/south =
30° north/south =
equator =
Poles = high pressure
60° north/south = low pressure
30° north/south = high pressure
equator = low pressure
66
What are some UK weather hazards?
- rain
- snow/ice
- drought
- hailstorms/thunderstorms
- wind
- heat waves
67
What are tropical storms called when they're in;
North America
South east Asia
Indian ocean
North America = hurricane
South east Asia = typhoon
Indian ocean = cyclone
68
What are the 3 requirements for tropical storms to form?
1. Sea surface temperature of more than 27°
2. Ocean depth of more than 50m
3. Location between 5°-20° for low pressure weather systems
69
What direction do tropical storms usually move to?
East due to the Coriolis effect
70
Tropical storms are ___ in shape, span hundreds of km wide, last _____ weeks, spin ____ in the northern hemisphere and spin ______ in the southern hemisphere.
Tropical storms are CIRCULAR in shape, span hundreds of km wide, last 1-2 weeks, spin ANTICLOCKWISE in the northern hemisphere and spin CLOCKWISE in the southern hemisphere.
71
What is the eye of a tropical storm?
- calm centre of the storm
- low pressure, clear skies, light winds
- warm air descends.
72
What is the eye wall in a tropical storm?
- the area surrounding the eye
- strongest winds, heaviest rain, thick clouds (up to 15m tall)
- most dangerous part.
72
What are the edges in a tropical storm?
- thinner clouds
- lighter rain and wind
73
What factors increases the damage storms cause?
1. distribution
2. frequency (climate change heats oceans)
3. intensity
74
What are primary effects of tropical storms?
- damage to infrastructure
- floods/sewage overflow
- flying debris injuries
- cables and pylons damaged
- water damage
75
What are secondary effects of tropical storms?
- causing homelessness
- isolated with no healthcare, illness
- cant work to earn money
- damaged roads, stopping aid
- damage to crops, livestock, food shortages
76
What are immediate responses for tropical storms?
- warnings for evacuation
- temporary shelters, food/water
- sending aid quickly
- bodies found and buried to stop diseases from spreading
77
What are long term responses for tropical storms?
- repair flooded homes, roads
- improve food defences
- encourage economic recovery with tax relief
- improve weather forecasting
- stormproof infrastucture
78
When and where did Hurricane Katrina hit?
August 2005. New Orleans, USA (HIC)
79
What category was katrina, and how strong were the winds?
Category 3 (on the Saffir-Simpson scale)
Around 200km/h
80
What were the primary effects?
- over 1800 people died
- 80% of New Orleans was flooded since levees broke
- electricity cut off for 3 million people
- 150,000 homes were destroyed
81
What were the secondary effects?
- over 1 million people were left homeless
- 2400 businesses closed/went bankrupt
- diseases caused from contaminated water
82
What were some short/long term responses?
Short;
- 1.7 million people evacuated
- 35,000 people rescued
- charities provided aid
Long;
- spent $20 billion on flood defences
- water that flooded was pumped into a lake
83
What is climate change?
Changes in the earth's average temperature
84
What is the quaternary period?
From today to 2.6 million years ago, earth was warmer before
85
How long do the two periods last, and what are the temperatures like?
Glacial periods (cold and lasting 100,000 years)
Interglacial periods (7° warmer lasting 8,000-12,000 years)
86
What is the greenhouse effect?
When greenhouse gases absorb heat that's been reflected off the earth and re-radiate this heat back towards Earth
87
What are the 4 evidence of climate change, explain why?
1. Ice cores = each year a new layer of ice freezes on top of an ice sheet, examining the gases shows the temperature from thousands of years ago
2. Tree rings = each year a new ring forms in the trunks of trees, they are thicker in hot/wet conditions, examining rings tell us conditions for last 10,000 years
3. Temperature records = recorded globally since 1950, its more reliable/accurate now
4. Plant pollen = preserved in sediment, comparing them indicate differences in climate
88
What are the 3 human causes of climate change?
1. Deforestation = photosynthesis takes in CO2, less is removed, and as trees are burned it releases more
2. Farming = digestive systems of cows produce methane, along w rice paddies which are greenhouse gases
3. Burning fossil fuels = including coat, petrol, natural gas, crude oil, CO2 is released
88
What are the 3 natural causes of climate change?
1. Solar output variation = period of high output increases earth's temperature
2. Volcanic activity = particles reflect sun's radiation away, cooling it down (volcanic winter), and also releases greenhouse gases
3. Earth's orbit = changes from circular to elliptical, when earth is closer more radiation reaches us, warming it (interglacial eras)
89
What are the 5 impacts of climate change overall?
1. Changing precipitation patterns
2. Changing distribution of species (malaria can spread by mosquitoes)
3. Reduction of biodiversity (habitats destroys, cant evolve, extinctions)
4. Melting ice (flooding coastal habitats)
5. Sea surface temperature increases (more cyclones/corals bleached)
90
What are the 5 impacts of climate change on people?
1. Deaths due to heat exhaustion
2. Problems with water sources (droughts, wars for water)
3. Lower crop yield (starvation or malnutrition)
4. More extreme weather events (financial consequences, tropical storms)
5. Loss of coastal areas ( inhabitable, forcing migration, poverty, overcrowded areas and wars
91
What are mitigation strategies for reducing greenhouse gases?
- alternative energy production, like solar panels
- reforestation to neutralise carbon footprint
- international agreements to reduce carbon emissions
- carbon capture + storage, bill gates invested in CO2 being transported underground safely.
92
What are adaptations of climate change?
- coping with rising sea levels with flood defences, building houses on stilts for LICs
- changing agricultural systems, meat substitutes, biotechnology for crop resistance
- managing water supply, drier areas capturing rainwater, using efficient taps
