Hazards PG U3 Y13

What is the definition for a hazard?

Atmospheric, hydrologic, geologic and wildfire phenomena that have the potential to affect humans, their structures of activities

What is a natural phenomenon?

A physical event that does not effect humans

What is a natural hazard?

A natural phenomenon that occurs in a populated area, causing large numbers of fatalities or property damage

What is an example of human interference causing natural hazards?

Destroying coral reefs removes the shores firs line of defence against ocean currents and storm surges

What are the three categories of hazards?

• geophysical - hazards caused by internal earth processes or tectonic activity or mass movement

• Hydrological - hazards caused by the occurrence, movement and distribution of surface and underground water

• Atmospheric - processes operating in the atmosphere resulting in extreme weather or atmospheric conditions

What are the characteristics of natural hazards?

• clear causes/ origins

• Little or no warning beforehand

• Distinctive effects

• Scale and impact required an emergency response

What does dregg’s model show?

That a natural disaster occurs when a physical hazard and a vulnerable population intersect

What is a natural disaster stated by 2 organisations?

• UN - when over 10 people are killed, over 100 are effected, state of emergency is declared and international assistance is needed

• 1990 Swiss Reinsurance - an event where at least 20 died or over $16 million in damage is caused

What is meant by vulnerability?

Being more susceptible to the effects of the event

Why may some people be more vulnerable to hazards?

• access to healthcare → if the majority of the population is already healthy

• Ages of individuals → older population more vulnerable to injuries

• Access to transport → to leave the area for safety

• Knowledge of hazard occurring → so there is time to plan and prepare reducing deaths and injuries

the risk of disaster grows as…

global hazards and people’s vulnerability increases, whilst their capacity to cope decreases

What does perception mean?

The way someone understands or interprets a hazard, which may affect how they respond to the hazard

What does the model of vulnerability show?

How different factors such as social, geographic, economic and environmental conditions affect people’s susceptibility to hazards and the impact of hazards

What are the 4 types of responses to hazards?

• fatalism - accepting the fact that hazards and their effects are inevitable as it’s part of ‘God’s Will’

• Adaptation - believing that you can prepare for and survive the event from prediction and prevention

• Fear - moving away from the area as they feel vulnerable to an event and don’t feel safe living there

• Domination - believing hazards are predictable and can be better understood with scientific research

What are some influences that may affect response to hazards?

• level of education

• Past experience

• Employment status

• Religion, cultural, ethnic background

• Family and marital status

What is meant by prediction?

Monitoring the risk of the hazard

What is meant by management?

How the hazard is dealt with

What is socio-economic disruption?

The disruption to social lifestyle or economic aspects

What is meant by environmental degredation?

Deteriation of the natural environment

What is the risk management cycle?

4 strategies that can reduce the impacts of effects of the event:

• preparedness - educating people on how to prepare and act before, during and after a hazard

• Response - immediate help saves people and provides resources

• Recovery - rebuilding infrastructure and rehabilitating affected people

• Prevention - reducing the scale of the next disaster by implementing strategies such as hazard resistant infrastructure

What are the positive and negatives of the risk management cycle?

Positive:

• easy to remember

• centred around the 4 Ps (prediction, preparation, protection, prevention)

• Can be applied to other places and different hazards

Negatives:

• too generic and unquantifiable

What is the Park Model (1991)/ Disaster Response Curve?

• describes a sequence of phases following a hazard event

• It refers to the strategies and events taken to bring ‘back to normal’ after a disaster

What are the stages in the Disaster Response Curve?

1. Pre disaster

2. Hazardous event occurs

3. Search rescue and care

4. Relief (outside help)

5. (Sometimes occurs) joy of people who have survived

6. Reconstruction and recovery of area

What are the positives and negatives of the Park Model (1991)

Positives:

• focuses on the three Rs (relief, rehabilitation and reconstruction) that help understanding of recovery after the event

• Useful when comparing hazard events due to their diff curves

Negatives:

• doesn’t account for different levels of economic development or other issues

How old is the earth?

Around 4.5 million years old

What shape is the earth?

A geoid shape → bulges at equator and flatter at poles caused by centrifugal forces generated by the earths rotation

What is the inner core?

• Around 5500 degrees C

• Consists of mostly iron and nickel

What is the outer core?

• Similar temps to inner core

• Made of mainly iron

• Creates electromagnetic field

What is the mantle?

• widest section of earth

• Temps reach 5000 degrees c

• Upper mantle is rigid and solid

• Lower mantle is liquid iron and magnesium

What is the crust?

• thinnest and lightest layer of the earth due to abundance of oxygen, aluminium, silicon etc

• Crust split into 2: continental (sial) and oceanic (sima)

What is the continental crust?

• 30-70km thick

• Over 1500 mill years old

• Composed of granite, silicon, aluminium and oxygen

What is the oceanic crust?

• 6-10km thick

• Less than 200mill years old

• Composed of basalt, silicon, magnesium, oxygen

Why may some places suffer more from earthquakes than others?

1. Infrastructure → better structurally designed areas for earthquakes suffer less

2. Preparedness → regular earthquake drills and knowing how to respond in the event reduces scale of disaster

3. Development levels → LICS have less rigorous building standards meaning they’re unable to cope with the aftermath of an earthquake whereas HICS suffer less human loss but more financial loss from reconstruction

What are convection currents?

• hot magma near the outer core rises through the mantle due to it being less dense

• As the magmas reaches the lithosphere, it cools and becomes more dense

• The magmas reaches sinks back down to the outer core

• This creates large convection currents, causing plate movements