hazards

Question 1

What is a natural hazard?

Answer 1

A natural process which could cause death, injury or disruption to humans or destroy property and possessions

Question 2

What is a natural disaster?

Answer 2

A natural hazard that has happened

Question 3

What are the two main types of natural hazards?

Answer 3

geological
meteorological

Question 4

What is a geological hazard?

Answer 4

caused by land and tectonic processes
e.g. volcanoes, earthquakes, landslides and avalanches

Question 5

What is a meteorological hazard?

Answer 5

caused by the weather and the climate
e.g. tropical storms, extreme weather

Question 6

What factors affect hazard risk?

Answer 6

vulnerability
capacity to cope
nature of the natural hazard

Question 7

What is vulnerability?

Answer 7

1) The more people that are in an area exposed to natural hazards, the greater the probability they will be affected by a natural hazard.

2) For example, an area with high population density on a floodplain (like much of Bangladesh) is very vulnerable to flooding caused by extreme weather, and a city at the base of a volcano (like Naples, Italy) is very vulnerable to volcanic eruptions.

Question 8

What is the capacity to cope?

Answer 8

1)The better a population can cope with an extreme event, the lower the risk of them being severely affected.

2) higher-income countries (HICs) can better cope with flooding because they can afford to build flood defences and evacuate people.

Question 9

What is the nature of a natural hazard?

Answer 9

1)Type — the risk from some hazards is greater than others.
E.g. tropical storms can be predicted and monitored, giving people time to evacuate.
But earthquakes happen very suddenly, with no warning, so it’s much harder to protect people.

2)Frequency - natural hazards that occur more often may carry a higher risk.

3)Magnitude - more severe natural hazards tend to have the greatest effects.
E.g. a magnitude 9.0 earthquake that struck Japan in 2011 killed over 15 000 people, whereas a 6.3 magnitude earthquake in L’Aquila, Italy, in 2009 killed around 300 people.

Question 10

What is the primary effect of a natural hazard?

Answer 10

immediate impacts caused by the hazard itself

Question 11

What are examples of the primary effects of a hazard?

Answer 11

Buildings and roads are destroyed by earthquakes, - volcanic eruptions or tropical storms.

People are injured or killed, e.g. when buildings collapse.

Crops and water supplies can be damaged or contaminated

Electricity cables, gas pipes and communication networks can be damaged, cutting off supplies.

Question 12

What is the secondary effect of a natural hazard?

Answer 12

happen later on, often as a result of the primary effects

Question 13

What are examples of the secondary effects of a hazard?

Answer 13

The initial hazard can trigger other hazards, e.g. earthquakes can trigger tsunamis (enormous waves caused by seawater being displaced).

Aid and emergency vehicles can’t get through because of blocked
roads or bridges — this can cause more deaths.

A shortage of clean water and a lack of proper sanitation make spreading disease easier.

Food shortages can occur if crops are damaged, livestock are killed, or supply lines are blocked.

The country’s economy can be weakened - damage to businesses can cause unemployment, and the reconstruction process can be costly.

Question 14

What are immediate responses?

Answer 14

1) Evacuate people (before the hazard occurs if possible).

2) Treat the injured and rescue anyone cut off by damage to roads or bridges.

3) Recover dead bodies to prevent disease from spreading.

4)Provide temporary electricity and gas supplies if regular supplies have been damaged.

5) Provide food, drink and shelter to people without homes.

6) Foreign governments or charities may send aid workers, supplies

Question 15

what are the long term responses?

Answer 15

1) Repair homes or rehouse people who have lost their homes.

2) Repair or rebuild buildings, roads, railways and bridges.

3) Reconnect broken electricity, water, gas and communication connections.

4) Improve forecasting, monitoring and evacuation plans.

5) Improve building regulations so that buildings can withstand similar hazards in the future.

6) Boost economic recovery, e.g. by promoting tourism.

Question 16

What is the earth’s crust made up of?

Answer 16

tectonic plates

Question 17

What are the two types of crust?

Answer 17

continental
oceanic

Question 18

What is a continental crust?

Answer 18

Thicker (30-50 km) and less dense.

Question 19

What is the oceanic crust?

Answer 19

Thinner (5-10 km) and more dense.

Question 20

Why do the plates move?

Answer 20

Because of convection currents in the mantle

Question 21

What is it called where two plates meet?

Answer 21

pate boundaries/margins

Question 22

What are the three types of plate margins?

Answer 22

destructive
constructive
conservative

Question 23

What is a destructive plate margin?

Answer 23

These are where two plates are moving towards each other.

Where an oceanic plate meets a continental plate, the denser oceanic plate is subducted (forced down into the mantle) and destroyed, creating gas-rich magma. Volcanoes and ocean trenches occur here.

The ground is folded upwards where two continental plates meet, creating fold mountains.

Question 24

What is an example of a destructive plate boundary?

Answer 24

Along the west coast of South America, the oceanic Nazca plate is subducted beneath the continental South American plate, creating the Atacama Trench.

Question 25

What is a constructive plate boundary?

Answer 25

Constructive margins occur when two plates move away from each other. Magma rises from the mantle to fill the gap and cools, creating a new crust.

Question 26

What is an example of a constructive plate boundary?

Answer 26

The movement of the Eurasian and North American plates away from one another forms the mid-Atlantic ridge.

Question 27

What is a constructive plate boundary?

Answer 27

conservative margins are where two plates are moving sideways past each other or are moving in the same direction but at different speeds. Crust isn't created or destroyed.

Question 28

What is an example of a conservative plate boundary?

Answer 28

San Andreas Fault

Question 29

Where do volcanoes occur?

Answer 29

at Destructive and Constructive Plate Margins

Question 30

How do volcanoes form at destructive plate boundaries?

Answer 30

The denser oceanic plate moves down into the mantle, where it melts. A pool of magma forms, which then rises through cracks in the crust called vents. The magma erupts, forming a volcano.

Question 31

How do volcanoes form at constructive plate boundaries?

Answer 31

The magma rises up into the gap created by the plates moving apart, forming a volcano.

Question 32

Where do earthquakes occur?

Answer 32

All three types of boundaries?

Question 33

How do earthquakes form at destructive margins?

Answer 33

Tension builds when one plate gets stuck as it moves past the other.

Question 34

How do earthquakes form at constructive margins?

Answer 34

Tension builds along cracks in the plates as they move away from each other.

Question 35

How do earthquakes form at conservative margins?

Answer 35

Tension builds up when plates that are grinding past each other get stuck.

Question 36

What happens when the plates eventually jerk past each other?

Answer 36

They send out shock waves. These vibrations are the earthquake

Question 37

What is the epicentre?

Answer 37

the point on the earth's surface straight above the focus

Question 38

What is the focus of an earthquake?

Answer 38

The point on the earth where the earthquake starts

Question 39

How are earthquakes measured?

Answer 39

the moment magnitude scale

Question 40

What is the moment magnitude scale?

Answer 40

Measures the amount of energy an earthquake releases (called the magnitude). It is a logarithmic scale - so a magnitude 7 earthquake would cause ten times as much ground shaking as a magnitude 6 earthquake.

Question 41

Where in New Zealand did an earthquake happen?

Answer 41

Kaikoura

Question 42

When did the earthquake happen in New Zealand?

Answer 42

14th November 2016

Question 43

What plate boundary caused the New Zealand earthquake?

Answer 43

Destructive and conservative - the Pacific plate is subducting beneath the Australian plate to the north, and sliding past it to the south.

Question 44

What was the magnitude of the New Zealand earthquake?

Answer 44

7.8

Question 45

What were the primary effects of the New Zealand earthquake?

Answer 45

2 people died and over 50 people were injured. Tens of thousands of homes were damaged, and some were destroyed. 60 people needed emergency housing. The total cost of damage was around US S8.5 billion. Over 200 km of road and over 190 km of rail line were destroyed. Communications, water, sewerage and power supplies were cut off.

Question 46

What were the secondary effects of the New Zealand earthquake?

Answer 46

The earthquake triggered up to 100 000 landslides, which blocked major road and rail routes. A major landslide blocked the Clarence River, leading to flooding and the evacuation of 10 farms. The earthquake generated a tsunami with waves of around 5m, leaving debris up to 250 m inland.

Question 47

How did New Zealand respond to the earthquake?

Answer 47

quickly

Question 48

What were the immediate responses to the New Zealand earthquake?

Answer 48

A tsunami warning was issued quickly, and residents of coastal areas were told to move to higher ground. Hundreds of people were housed in emergency shelters and community centres. 200 of the most vulnerable people were evacuated from Kaikoura by helicopter within 24 hours of the earthquake. Power was restored to most places within a few hours. Temporary water supplies were set up. International warships were sent to Kaikoura with supplies such as food, medicine and portable toilets.

Question 49

What were the long-term responses to the New Zealand earthquake?

Answer 49

The Kaikoura District Council provided $5.3 million in funding to help rebuild the town's water systems and harbour. Most road and rail routes were repaired and reopened within 2 years. The Kaikoura Mayoral Earthquake Relief Fund was established to help residents who couldn't afford basic supplies, and donations came from around the world. By March 2017, a permanent water main had been laid in Kaikoura. The new pipe was designed to move with future earthquakes and not break.

Question 50

Where in Nepal did the earthquake happen?

Answer 50

Gorkha

Question 51

When did the Nepal earthquake happen?

Answer 51

25th April 2015

Question 52

What plate boundary caused the Nepal earthquake?

Answer 52

Destructive — the Indo-Australian plate is being subducted beneath the Eurasian plate.

Question 53

What magnitude was the Nepal earthquake?

Answer 53

7.8

Question 54

What were the primary effects of the Nepal earthquake?

Answer 54

Around 9000 people died, and more than 22.000 were injured. An estimated 800,000 buildings were damaged or destroyed. 4 million people were left homeless. The cost of damage was over US S5 billion. Roads and bridges were destroyed. Water tanks and pipes were destroyed, leaving 2 million people without access to clean water and sanitation.

Question 55

What were the secondary effects of the Nepal earthquake?

Answer 55

The earthquake triggered avalanches on Mount Everest which killed 18 people. Many mountain roads were blocked by landslides, preventing emergency aid from reaching remote areas. A lack of clean water caused outbreaks of typhus, which killed at least 13 people.

Question 56

How did Nepal respond to the earthquake?

Answer 56

slowly and less effective

Question 57

What was the immediate response to the Nepal earthquake?

Answer 57

India and China sent teams to help residents rescue people trapped by debris, but a lack of tools and machinery slowed down rescue efforts. People tried to recover the dead and treat the injured, but damaged roads made it hard for emergency workers and aid to get through. Charities such as Oxfam provided medicine, food and temporary water supplies. The Red Cross set up emergency shelters for 130 000 families who had lost their homes.

Question 58

What were the long-term responses to the Nepal earthquake?

Answer 58

The World Bank Group financed $500 million worth of projects to build earthquake-resistant housing, and repair roads and irrigation systems. Some projects are still ongoing. the road from Nepal into Tibet was reopened 2 years after the earthquake, but many other routes remain damaged Many heritage sites were reopened in June 2015 to encourage tourists back to the area. Water supply is being restored, but two years after the event, many people still didn't have access to clean water. NGOs are working with residents to increase their resilience to disasters, for example by providing alternative energy sources.

Question 59

Why do people live near tectonic hazards?

Answer 59

* They've always lived there - moving means leaving their jobs or families. * In wealthier countries, effective monitoring and evacuation plans can minimise risk. * They're confident that their government will support them after an earthquake or volcanic eruption. In 2001, the Italian government provided financial aid and tax breaks for local residents when Mount Etna erupted. * The minerals from volcanic ash makes volcanic soil very fertile, attracting farmers. For example, the mineral-rich soil around Mount Etna is ideal for producing grapes. * Volcanoes are tourist attractions, so lots of people live nearby to work in the tourist industry - Mount Etna receives hundred of thousands of visitors when it is erupting.

Question 60

What can management do to the effects of tectonic hazards?

Answer 60

reduce them

Question 61

As a management strategy, what does monitoring do?

Answer 61

Earthquakes: Seismometers and lasers monitor the earth's movements and can be used in early warning systems to give a small but vital warning before a large earthquake occurs. Volcanic eruptions — scientists can monitor the tell-tale signs that come before an eruption, such as tiny earthquakes, escaping gas, and changes in the shape of a volcano.

Question 62

As a management strategy, what does prediction do?

Answer 62

Earthquakes - cannot be reliably predicted, but scientists can forecast where they may occur by monitoring the movement of tectonic plates. Volcanic eruptions — can be predicted if scientists monitor volcanoes closely.

Question 63

As a management strategy, what does protection do?

Answer 63

Earthquakes - new buildings can use reinforced concrete that absorb an earthquake's energy. Existing buildings and bridges can be strengthened with steel frames so they're less likely to collapse. Automatic shut-off switches can turn off gas and electricity supplies to prevent fires. Volcanic eruptions - buildings can be strengthened so that they're less likely to collapse under the weight of ash. Trenches and barriers have been used to try to divert lava away from settlements, but with little success.