Geography Natural hazards

Question 1

What is a Hazard?

Answer 1

A hazard is a potential threat to human life and property caused by an event ; an event is only a hazard when it is a threat to human life.

Question 2

What is a multi-hazardous environment?

Answer 2

Where many hazards may be present and where these may occur simultaneously.

Question 3

What are the three major types of geographical hazards?

Answer 3

Geophysical - Caused by land processes ( tectonic plates) e.g. Volcanoe
Atmospheric - Caused by atmospheric proceesses and conditions by weather e.g. wildfires
Hydrological - caused by water bodies and movement e.g. floods

Question 4

What is hazard preception and how do economy and experience affect it?

Answer 4

A persons view on how dangerous hazards are and the risk they pose. Wealthier people will be less frightful of a hazard compared to poorer people but can have a bigger loss. Experience can play a role as someone experienced with a certain hazard will have more knowledge on what to do.

Question 5

What are human responses to hazards?

Answer 5

Prediction ( Scienctific research), Adaptation, Mitigation, Management and Risk Sharing.

Question 6

What is Mitigation?

Answer 6

Strategies carried out to lessen the severity of a hazard (e.g. sandbags to offset impact of flooding).

Question 7

What is Fatalism?

Answer 7

The viewpoint that hazards are uncontrollable natural events, and any losses should be accepted as there is nothing that can be done to stop them.

Question 8

What is the Park Model?

Answer 8

The Park Model is a graphical representation of human responses to hazards, showing the steps carried out in the recovery after a hazard, giving a rough indication of time.

Question 9

What is the hazard management cycle and what does it show?

Answer 9

The Hazard Management Cycle is a systematic process that aims to reduce the impact of disasters by means of planning and response, learning and adaptation after the event.

Question 10

How is the earth structured?

Answer 10

Lithosphere (Crust), Ashenosphere, Mantle, Outer Core, Inner Core

Question 11

What energy sources are found internally in the earth?

Answer 11

Renewable sources of energy including the heat from gravity and nuclear or radioactive decay.

Question 12

What is ridge push?

Answer 12

Ridge push is a tectonic process involving the gravitational force that causes an oceanic plate to move away from a mid-ocean ridge. E.g Mid Atlantic Ridge

Question 13

What is slab pull?

Answer 13

Slab pull is a geophysical process that refers to the force exerted by a subducting tectonic plate as it sinks into the mantle.

Question 14

What is Sea-floor spreading?

Answer 14

Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity.

Question 15

What are convection currents?

Answer 15

Convection currents are heat-driven cycles that move energy from one location to another, primarily occurring in gases and liquids caused by variations of temperature and density.

Question 16

What happens to the plates at each boundary Constructive/Destructive/Conservative?

Answer 16

Constructive - Plates move away from each other.
Destructive - The plates move towards each other.
Conservative - Slide past each other, get stuck and eventually slip.

Question 17

What characteristics and landforms occur at Constructive plate boundaries?

Answer 17

Deep sea trenches, Rift Valleys, Ocean Ridges, shield volcanoes.

Question 18

what landforms/characteristics occur at destructive plate boundaries?

Answer 18

Destructive plate boundary occurs when an oceanic plate is forced under a continental plate creating fold Mountains and Oceanic trenches.

Question 19

What is seismicity?

Answer 19

The occurrence or frequency of earthquakes in a region.

Question 20

What is vulcanicity?

Answer 20

Molten rock/magma erupting onto the surface of the Earth or a solid-surface planet, moon or asteroid.

Question 21

What are young fold mountains/how are they formed?

Answer 21

Young fold mountains are mountains that are formed by the folding of the earth’s crust due to tectonic activity and are less than 15 million years old.

Question 22

What are rift valleys/ how are they formed?

Answer 22

Rift valleys are elongated lowland regions that form due to geological processes such as extensional tectonics, faulting and pulling apart of the lithosphere. e.g. East African rift

Question 23

What are ocean ridges/how are they formed?

Answer 23

An oceanic ridge system is formed during tectonic activity whereby tectonic plates move apart and create gaps.

Question 24

What are island arcs/how are they formed?

Answer 24

An island arc is a chain or group of islands that forms from volcanic activity along a subduction zone.

Question 25

How/Why do volcanoes erupt?

Answer 25

When enough magma builds up in the magma chamber, it forces its way up to the surface and erupts ; eruptions can also be triggered by human or natural factors.

Question 26

What are magma plumes?

Answer 26

Magma plumes are areas of hot, upwelling mantle pushed by convection currents.

Question 27

How are volcanoes distributed globally?

Answer 27

Most volcanoes occur on plate margins in linear clusters at destructive margins (e.g. South American Plate) & constructive plate margins (e.g. Mid-Atlantic Ridge).

Question 28

What are the natural hazards that can occur with volcanic events?

Answer 28

lava flows, mudflows, pyroclastic flows, acid rain, tephra.

Question 29

What are pyroclastic flows?

Answer 29

A pyroclastic flow is a fast-moving current of hot gas and volcanic matter that flows along the ground away from a volcano usually >800 °C/ average speeds of 100 km/h - 700km/h.

Question 30

What is tephra?

Answer 30

Rock fragments and particles ejected by a volcanic eruption.

Question 31

What are Social/Economic/Political impacts of a volcano?

Answer 31

Social - Roads can be blocked and buildings can be destroyed, airlines denied flight. Economic - Cost of damages / Many businesses can shut down for a long time, tourism can be paused. Political - World Leaders cannot fly as ash will spread and prevent flying and pressure to respond quickly to needs.

Question 32

What are primary impacts of volcanoes?

Answer 32

When volcanoes erupt they can spew hot, dangerous gases, ash and lava causing disastrous loss of life and property, especially in heavily populated areas.

Question 33

What are secondary impacts of a volcano?

Answer 33

Roads can become blocked by solidified lava flows and airports can be shutdown making it difficult to travel around.

Question 34

Case Study: What were the impacts and responses to the Iceland 2010 volcanic eruption?

Answer 34

- Ten million passengers were affected, and more than 100,000 flights were cancelled all over Europe. - The cost to the aviation industry was estimated to be over £1.2 billion. - The volcano released approximately 150,000 tonnes of CO2 each day, or approximately 4.5 million tonnes of carbon dioxide by 19 April 2010.

Question 35

Which plates create earthquakes?

Answer 35

Most seismic activity occurs at three types of plate boundaries—divergent, convergent, and transform.

Question 36

How are earthquakes distributed globally?

Answer 36

80%+ of large earthquakes occur around the edges of the Pacific Ocean, known as the 'Ring of Fire'; this where the Pacific plate is being subducted beneath the surrounding plates.

Question 37

How is the magnitude of earthquakes measured?

Answer 37

They are measured by using seismometers and then are measured on The Richter scale then the intensity is measured on The Mercalli scale.

Question 38

How is the magnitude of a volcano measured?

Answer 38

Volume of products and eruption cloud height are studied then used for the VEI (Volcanic explosivity Index)

Question 39

What are forms of seismic hazards?

Answer 39

Earthquakes, tsunamis, liquefaction and landslides.

Question 40

What are the Social/Economic/Environmental impacts of earthquakes?

Answer 40

Social - Many families become seperated/lack of access to food and water. Economic - Cost of damages, businesses closed/ destroyed. Environmental - Disruption of soil and vegetation, soil Liquefactions.

Question 41

What are the primary impacts of an earthquake?

Answer 41

The primary effects of an earthquake include ground shaking, ground rupture, and landslides.

Question 42

What are secondary impacts of an earthquake?

Answer 42

Secondary effects may include subsidance, tsunamis, fires, contamination of water supplies, gas leaks, and power outages.

Question 43

Case Study: What were the impacts and responses to the Haiti Earthquake 2010?

Answer 43

The earthquake was 7 on the richter scale left more than 1.5 million people homeless, killed 222,570 people and injured 300,000. Many countries responded to appeals for aid with rescue and medical teams, cost of damage 14 billion US.

Question 44

What are wildfires?

Answer 44

A fire that starts in a wild area such as a forest spreading rapidly and causing great damage.

Question 45

What conditions help wildfires?

Answer 45

Dry seasons resulting in dry plants and high temperatures but also wind helping the spreading.

Question 46

What are human and natural causes of fire?

Answer 46

Human - Slash and burning, discarded cigarettes, campfires. Natural - Lightning and high temperatures

Question 47

What are the Social/Economic/Environmental impacts of wildfires?

Answer 47

Social - Evacuation and homes destroyed Economic - Cost of damage (agriculture) and firefighters Environmental - Animal habitats destroyed and lots of CO2 emitted from the flames.

Question 48

What are the primary impacts of wildfires?

Answer 48

Disruption to transport, infrastructure/surrounding businesses and smoke threatening health.

Question 49

What are secondary impacts of wildfires?

Answer 49

Burnt areas become prone to flash floods, soil erosion, landslides and desertification.

Question 50

Case Study: What are the impacts and responses to the Alberta, Fort Mcmurray wildfire 2016?

Answer 50

- Estimated damage cost of C$9.9 billion (US$7.61 billion) - 500 species of wildlife lost their habitats or were in danger due to the fire. - 90,000 forced to evacuate homes in Fort Mcmurray.

Question 51

What are tropical storms?

Answer 51

A tropical cyclone is a rapidly rotating storm system with a low-pressure area with strong winds and terential rain.

Question 52

How are tropical storms formed?

Answer 52

They're formed by sea temperatures of 27°C or more and converging winds between 39mph and 73mph on the ocean surface forcing air to rise and form storm clouds over 60m of water.

Question 53

What hazards do tropical storms trigger?

Answer 53

High winds, terential rain, storm surges, coastal flooding, river flooding and landslides.

Question 54

What is the global distribution of tropical storms?

Answer 54

Most tropical storms form 5–15° north and south of the Equator also more tropical storms occur in the northern hemisphere.

Question 55

What are the Social/Economic/Environmental impacts of tropical storms?

Answer 55

Social - Roofs can be blown off houses, people may be trapped in their own buildings and a lack of clean water Economic - Unemployment caused by businesses being damaged Environmental - Coastal habitats like beaches and mangroves can be damaged by storm surge floods.

Question 56

What are primary impacts of tropical storms?

Answer 56

Immediate effects of strong winds, high rainfall and storm surges.

Question 57

What are secondary impacts of tropical storms?

Answer 57

Landslides which can cause people to become homeless and can block roads and railways.

Question 58

LIC Tropical Storm Case Study: What are the impacts and responses to Typhoon Haiyan 2013?

Answer 58

The typhoon damaged 1.1 million houses destroyed, 33 million coconut trees and pushed approximately 2.3 million people into poverty. Overall damage is estimated at $13 billion.

Question 59

HIC Tropical Storm Case Study: What are the impacts and responses to Hurricane Sandy?

Answer 59

346,000 houses were damaged/destroyed in New Jersey, $20Billion damage to Subway stations in New York . More than 18,000 flights were cancelled.

Question 60

Why are LICs more affected by hazards than HICs?

Answer 60

HICs have more money to spend on hazard proof buildings and technology to predict hazards but also for recovery whilst LICs don't have funds for technology and have lower economies to recover from hazards.