Physical - Hazards

Question 1

What is a natural hazard?

Answer 1

A perceived event that threatens both life and property. Often results in disasters that cause loss of life and/or built environment.

Question 2

Adaption

Answer 2

Attempts by people/communities to live with hazard events. By adjusting living conditions to reduce vulnerability.

Question 3

Fatalism

Answer 3

View of a hazard event that suggests people cannot influence/shape that outcome so nothing can be done to mitigate against it. People put in place limited or no preventative measures. (‘Gods will’).

Question 4

Perception

Answer 4

The way an individual/group views the threat of a hazard event which will determine the course of action taken by individuals or response they expect from governments or organisations.

Question 5

What factors affect our perception of a hazard?

Answer 5

Socio-Economic 
Level of education 
Occupation/employment status 
Religion, culture or ethnic background 
Family and martial status 
Past experience 
Values, personality, expeditions

Question 6

What different ways can a hazard be seen as?

Answer 6

Fatalism (or acceptance)
Adaption (prediction/protection/prevention)
Fear

Question 7

Community preparedness/risk sharing

Answer 7

Prearranged measures that aim to reduce loss of life and property damage through public education and awareness programs, evacuation procedures, the provision of emergency ,radical, food and shelter supplies and taking out insurance.

Question 8

Frequency

Answer 8

Distribution of a hazard through time.

Question 9

Integrated risk management

Answer 9

Process of considering social, economic, political factors involved in risk analysis; determining acceptability of damage/distribution and deciding on factors to be taken t minimise damage/disruption.

Question 10

Magnitude

Answer 10

Assessment of size of impact of Hazard event.

Question 11

Prediction

Answer 11

Ability to give warning so action can be taken to reduce impact of event. Improved monitoring, info and communications tech mean predictions hazards has become more important in recent years.

Question 12

Primary effects

Answer 12

Effects of a hazard that result directly from the event.

Question 13

Resilience

Answer 13

Sustained ability of individuals or communities to be able to utilise available resources to respond to, withstand and recover from effects of natural hazard event. Communities that are resilient are ale to minimise effects of event enabling them to return to normal life as soon as possible.

Question 14

Secondary effects

Answer 14

Effects that result from primary impacts of event.

Question 15

Distribution

Answer 15

Spatial coverage of hazard and refers to the area affected by a single event some are localised but some are world wide.

Question 16

What hazard can affect the world on a global scale and how?

Answer 16

Volcanic eruptions as they throw dust into the atmosphere and can cause short-term climate change.

Question 17

What are some secondary effects of earthquakes?

Answer 17

Soil liquefaction
Landslides
Tsunami 
Damage to people 
Damage to buildings 
Fires 
Floods

Question 18

What is a disaster/response curve?

Answer 18

It shows how events can have varying impacts over time.

In 1991 Park revised the model.

Question 19

What are the 3 layers of the earth?

Answer 19

Crust
Mantle
Core

Question 20

What is the temp of the core?

Answer 20

5000 degrees Celsius

Question 21

What are the 2 processes that make the core of the earth hot?

Answer 21

Primordial heat leftover from earths formation.

Radiogenic heat produced by radioactive decay.

Question 22

What elements is the crust made of?

Answer 22

Silicon, oxygen, aluminium, potassium, sodium.

Question 23

What is the thickness of the crust in the ocean?

Answer 23

6-10km

Question 24

What is the thickness of the crust below continents?

Answer 24

30-40km

Question 25

What is the thickness of the crust below mountains ?

Answer 25

70km

Question 26

What is the lithosphere?

Answer 26

It’s made of the crust and upper section of the mantle. It is roughly 80-90km thick.

Question 27

What is the Asthenosphere?

Answer 27

It lies beneath the lithosphere and is semi Milton so plates are able to float and move.

Question 28

Who first noticed that continents looked like they once fit together?

Answer 28

Francis bacon

Question 29

Who official published plate tectonic theory.

Answer 29

German, Alfred Wagner in 1912. And said that the earth once consisted of one single continent over 300 million years ago. This super continent was called Pangaea (which later split into 2 smaller ones: Laurasia in the north and Gondwanaland).

Question 30

What is a hot spot?

Answer 30

Areas around the core that generate thermal convection currents in the asthenosphere. Magma rises towards the crust and spreads before cooling and sinking.

Question 31

Name some landforms associated with plate movement

Answer 31

``` Oceanic ridges Rift Valleys Deep ocean trenches Island arc You fold mountains ```

Question 32

What is another word for ‘ridge push’ ?

Answer 32

Gravitational sliding

Question 33

What is slab pull?

Answer 33

At destructive plate boundaries a major component is the downward gravitational force acting on cold/dense descending plate as it sinks into mantle. This gravity generated force pulls whole oceanic plate down as a result of negative buoyancy.

Question 34

Lahars

Answer 34

Formed by volcanic ash mixing with water and flowing downhill. Essentially they are volcanic mudflows. In the Philippines, if a typhoon occurs after a volcanic eruption, lahars can result.

Question 35

Lava

Answer 35

``` Morton rock (magma) flowing onto the surface. Acid lava solidifies quick but basic lava (basaltic) tends to flow some distance before solidifying. ```

Question 36

Pyroclastic flows

Answer 36

Formed from mixture of hot gas over 800dc and tephra. After ejection from volcano they flow down side of mountain at speed of over 700km p hr.

Question 37

Tephra

Answer 37

Solid matter ejected by a volcano into the air. Ranges from volcanic bombs to ash.

Question 38

Where can volcanic activity be found?

Answer 38

Along oceanic ridges (where plates are moving apart) In subduction zones Rift valleys Hotspots

Question 39

What is the VEI?

Answer 39

The Volcanic Eruption Index and it measures the magnitude of a volcanic eruption.

Question 40

What are the primary impacts of a volcanic eruption?

Answer 40

Tephra Pyroclastic flows. Lava flows Volcanic gases

Question 41

What are some secondary impacts of volcanic eruptions?

Answer 41

``` Lahars Flooding Volcanic landslides Acid rain Climate change ```

Question 42

Earthquake

Answer 42

Crust of the earth is constantly moving, tends to be slow build up of stress within rocks. When pressure is released, parts of surface experience intense shaking motion.

Question 43

What is retrofitting?

Answer 43

In earthquake-prone areas buildings and other structures can be fitted with devices such as shock absorbers and cross-bracing to make them more earthquake proof.

Question 44

What is a tsunami ?

Answer 44

Giant sea waves generated by shallow-focus underwater earthquakes, violent volcanic eruptions, underwater debris slides and landslides into the sea.

Question 45

What are the 3 categories of earthquakes?

Answer 45

``` Shallow focus (0-70km) cause greatest damage plus account for 75% of all earthquake energy released. Intermediate focus (70-300km deep). Deep focus (300-700km deep). ```

Question 46

What are the different scales of measuring the magnitude of an earthquake?

Answer 46

``` Richter scale (0-8) increases by 30x with each unit. Momat Magnitude Scale (MMS) (1-10) Mercalli scale (1-12) ```

Question 47

What factors effect the impact of a tsunami?

Answer 47

``` Height of wave and distance travelled Length of event Extent to which warnings could be given Coastal physical geography Coastal land use and population density ```

Question 48

How do you decease an areas vulnerability of a hazard?

Answer 48

``` Building hazard resistant structures Education Fire prevention Emergency services Land-use planning Insurance Aid Tsunami protection ```

Question 49

Mitigation

Answer 49

Strategy designed to reduce risks to people/property from natural hazards, money spent prior to a hazardous event to reduce impact of it can result in substantial savings in life and property following event.

Question 50

What are storm surges?

Answer 50

Rapid rise in sea level where water is piled up against coastline far more than high tide level. Usually produced during passage of tropical storm where wind driven waves pile up water against coastline combined with ocean heaving upwards as result of much lower air pressure.

Question 51

What is a tropical storm called in the carribbean and Gulf of Mexico?

Answer 51

Hurricanes and accounts for 10% of all tropical revolving storms

Question 52

What are storms called in the Arabian Sea/bay of Bengal?

Answer 52

Cyclones and account for 8% of all tropical storms

Question 53

What are storms called off Southeast Asia?

Answer 53

Typhoons and 1/3 of all storms every ear occur here .

Question 54

What are retardants?

Answer 54

Chemicals sprayed on fires in order to slow them down. Composed of nitrates, ammonia, phosphates, sulphates and thickening agents.

Question 55

Pyrophytic vegetation

Answer 55

Pyrophytes are plants adapted to tolerate fire. Methods of survival include thick bark, tissue with high moisture content and underground storage structures.

Question 56

What are the 2 things that are needed for a fire to start and spread?

Answer 56

An ignition source | Fuel

Question 57

What are the effects of wildfires?

Answer 57

``` Loss of crops, timber, livestock Loss of lives Loss of property Release of toxic gases/particulates Loss of wildlife Damage to soil structure and nutrient content ```

Question 58

What are some secondary effects of fires?

Answer 58

Evacuation | Increased flood risk