The Challenges Of Natural Hazards

Question 1

What are natural hazards

Answer 1

Physical events such as earthquakes and volcanoes that have the potential to do damage to humans and property.

Question 2

What affects hazard risk?

Answer 2

-population growth
-climate change
-deforestation
-LIC’s are at more risk because they don’t have the money to protect themselves

Question 3

Structure of the earth

Answer 3

-the core
-mantle
-crust

Question 4

Crust

Answer 4

Split into major sections called tectonic plates.

Question 5

Crust

Answer 5

-oceanic and continental crust
-these plates move due to convection currents in the mantle and where they meet volcanoes and earthquakes occur.

Question 6

Margins

Answer 6

-destructive when they move towards each other
-constructive when they move away from each other
-conservative when they move past each other

Question 7

Volcanoes

Answer 7

Constructive margin - hot magma rises between the plates
Destructive margin - an oceanic plate subducts under a continental plate to melt and pressure forces magma up to form composite volcanoes

Question 8

Earthquakes

Answer 8

Constructive margin - small earthquakes as plates pull apart
Destructive margin - violent earthquakes as pressure builds and is then released
Conservative margin - plates slide past each other. They catch and then as pressure increases it is released

Question 9

Primary and secondary effects of earthquakes

Answer 9

Primary- property of buildings destroyed
- people injured or killed
- damaged services
-water, gas and electricity broken

Secondary- money lost repairing buildings
-blocked transport
-broken gas pipes cause fires
-broken water pipes lead to lack of fresh water

Question 10

Primary and secondary effects of volcanoes

Answer 10

Primary- property and farms destroyed
-people and animals killed and injured
-water supplies contaminated

Secondary- emergency services struggle to arrive
- ash breaks down leading to fertile land

Question 11

Immediate responses to hazards

Answer 11

-issue warnings
-rescue teams
-treat injured
-provide shelter
-extinguish fires

Question 12

Long term responses to hazards

Answer 12

-repair and rebuild properties
-restore utilities
-resettle locals elsewhere

Question 13

Distribution of tectonic activity

Answer 13

Along plate boundaries on the edge of continents and around the edge of the pacific.

Question 14

Monitoring

Answer 14

Seismometers measure earth movement.
Volcanoes give off gases

Question 15

Prediction

Answer 15

By observing monitoring data, this can allow evacuation before event.

Question 16

Protection

Answer 16

Reinforced buildings and making building foundations that absorb movement.
Automatic shut offs for gas and electricity.

Question 17

Planning

Answer 17

Avoid building in areas at risk.
Training for emergency services and planned evacuation drills.

Question 18

Nepal earthquake 2015 April - primary effects

Answer 18

-magnitude 7.8
-9000 deaths
-23000 injured
-500,000 homes destroyed
-26 hospitals destroyed
-50% of schools destroyed

Question 19

Nepal earthquake- secondary effects

Answer 19

-avalanche on mountain killing 19 people
-loss of tourism and income
-food shortages

Question 20

Nepal - immediate response

Answer 20

-raised $126 million
-red cross
-requested international help
-tents for 225,000 people

Question 21

Nepal - long term response

Answer 21

-international conference to discuss reconstruction
-tourist attractions reopened

Question 22

Global atmospheric circulation

Answer 22

At the equator the suns rays are most concentrated this means it is hotter.
High pressure = dry
Low pressure = wet
As the air heat rises - causing low pressure as it cools it sinks causing high pressure. Winds move from high pressure to low pressure. They curve because of the coriolis effect.

Question 23

Tropical storms

Answer 23

In low latitudes between 5 and 30 degrees north and south if the equator. Ocean temperatures needs to be above 27 degree and between summer and autumn.

Question 24

Sequence of a tropical storm

Answer 24

-Air is heated above warm tropical storms.
-Air rises under low pressure conditions
-strong winds form as rising air draws in more air and moisture causing torrential rain
-Cold air sinks in the eye so it is clear and dry
-heat is given off as it cools powering the storm
-on meeting land it loses source of heat and moisture so loses power

Climate change will affect tropical storms to. Warmer oceans will lead to more intense storms – but not necessarily more frequent ones


Question 25

Extreme weather in the UK

Answer 25

– Can cause flooding damaging homes and businesses
– Causes damage to properties and crops
– Lightning can cause fires or even death
– Heat waves cause breathing difficulties and can disrupt travel

Weather is getting more extreme due to climate change. Temperatures are more extreme and rain is more frequent and is leading to more flooding events.

Question 26

2003 UK heat wave

Answer 26

A heat wave bringing record temperatures to the UK hit in August 2003. Highest temperature was recorded in Kent

Question 27

Social economic and environmental effects on the heat wave

Answer 27

Social – 2000 UK deaths
-drinking water supplies were affected in some parts of the UK and hosepipe bans introduced

Economic – some railway tracks buckled in the heat. The London underground became unbearable. Some road services melted. Low river levels prevented some boats from sailing.

Environmental – it is thought that one third of the deaths caused by the heat wave in the UK were caused by poor air quality.

Question 28

Management strategies on the heat wave

Answer 28

– Met office issued weather warning
– Network rail in the UK imposed speed restrictions for trains when the temperature was above 30°

Question 29

Natural causes of climate change

Answer 29

– The suns energy on the Earth surface changes as the earths orbit is elliptical its axis is tilted on an angle
– Volcanic aerosols reflect sunlight away reducing global temperatures temporarily

Question 30

Human causes of climate change

Answer 30

– Fossil fuels release carbon dioxide with accounts for 50% of greenhouse gases
-greenhouse gases from methane
– Deforestation reduces ability to plants to absorb carbon through photosynthesis

Question 31

Social and environmental effects of climate change

Answer 31

Social
– Droughts
– Melting ice caps
– Increased skin cancer risk

Environmental
– Sea levels rise
– Warmer rivers affect marine wildlife

Question 32

Mitigation

Answer 32

– Alternative energy production will reduce CO2 production
– Planting trees helps remove carbon dioxide
– Carbon capture takes carbon dioxide from emission sources is stored underground

Question 33

Adaptation

Answer 33

– Managing water supplies by installing water efficient devices and increasing supply through plants
– Thames flood barrier reduces risk of flooding from rising sea levels

Question 34

Chile HIC earthquake causes

Answer 34

on a destructive plate margin the Naza plate subducts under the South American plate
magnitude: 8.8

Question 35

Chile earthquake effects

Answer 35

Primary:
- 500 deaths, 220,000 homes destroyed. Loss of power/water supplies
Secondary:
- 1500km roads damaged by landslides, coastal towns effected by tsunamis

Question 36

Chile earthquake response

Answer 36

Immediate response:
- emergency services quick to respond, highway repaired so aid could get through
Long term response:
- Government launched a housing reconstruction plan

Question 37

Typhoon Haiyan effect

Answer 37

• 6500 deaths
• 130,000 homes destroyed
• water and sewage systems destroyed causing diseases

Question 38

Typhoon Haiyan response

Answer 38

• The UN raised £190mil in aid
• Helicopter delivered aid to remote areas
• Oxfam replaced fishing boats

Question 39

volcanic hazards

Answer 39

ash cloud - small pieces of rock and glass that are throw into the atmosphere
gas - sulphur dioxide, water vapour, and carbon dioxide come out of the volcano
lahar - volcanic mudflow which flows down volcano valley
volcanic bomb - lava fragment that is ejected from the volcano

Question 40

Somerset floods effects

Answer 40

• 600 houses flooded
  -16 farms evacuated
• roads cut off
• sewage mixed with water
• cost £10mil

Question 41

Somerset floods management

Answer 41

• river banks built up
• more pumping stations
• £20mil flood action plan