What is a hazard?
A perceived natural event that has the potential to threaten both life and property
What is a disaster?
The realisation of a hazard that causes a significant impact (10+ killed, 100+ affected, $1 million+ damages)
What is vulnerability?
The ability to anticipate, cope with, resist and recover from a natural hazard
What is resilience?
The ability to protect lives, livelihoods and infrastructure from destruction and to restore areas after a natural hazard has occurred
What is the hazard risk equation?
Risk = (Hazard x Vulnerability)/Capacity to Cope
What are the 4 different models used to explain disasters?
Degg’s disaster model
PAR Model
Hazard risk equation
Hazard event profile
What does the PAR model show?
There are root causes which cause vulnerability over time, dynamic pressures and unsafe conditions, which combine with the hazard itself to increase the risk
The release model demonstrates vulnerability can be reduced and resilience increased by addressing root causes and hazard mitigation
Resilience
The ability of a system, community or society exposed to hazards to resist, absorb and recover from the effects of a hazard
Richter scale
A measurement of the height of waves produced by earthquakes on a logarithmic scale
Limitations of Richter scale
-Doesn’t account for spatial differences
-Doesn’t factor the impact on the environment and communities affected
-Inaccurate for magnitudes 6.5+
Mercalli scale
A relative measurement of the impacts of an earthquake based on peoples’ experiences
Limitations of the Mercalli scale
-unreliable, based off of different people’s experiences
-based on perception, so difficult to assign values
Moment magnitude scale (MMS)
A measure of the energy released by an earthquake based on the ‘seismic moment’ of an earthquake, on a logarithmic scale
Limitations of the moment magnitude scale
-hard to obtain quickly
-no human element
-underestimates larger earthquakes
Volcanic explosivity index (VEI)
A measurement of the volume of material ejected from a volcano, height of the cloud, and other observations on a logarithmic scale
Limitations of the volcanic explosivity index
-skewed towards explosive eruptions
-pyroclastic flows/lahars not accounted for
What do hazard event profiles show?
The physical characteristics of different types of hazards, allowing for the comparison of hazards
Limitation of hazard event profile
No human factors, so cannot tell how significant the impacts are since nothing on vulnerability
Secondary hazards of earthquakes
-Landslides
-Soil liquefaction
-Tsunamis
-Debris flow (soil, rock, vegetation + water which behaves like a fluid)
-Avalanches
-Changes to rivers
Primary hazards of volcanoes
Ash clouds
Lava flows
Pyroclastic flows
Gas eruptions
Secondary hazards of volcanoes
Tsunamis
Lahars
Jokulhlaups
Pyroclastic flows
Very large, dense clouds of hot ash and gases resulting from the frothing of magma in the vent of a volcano
Can reach 1000 degrees C and 100km/h
Ash/tephra
Rock fragments ejected into the atmosphere
Can vary from ‘volcanic bombs’ to ‘fine dust’
Lahars
Volcanic mudflows when rainfall mobilises volcanic ash (composed of sand and silt materials)
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Tectonics EQ139
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Tectonics EQ227
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Tectonics EQ317
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Globalisation EQ125
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Globalisation EQ223
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Globalisation EQ334
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Coasts EQ122
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Coasts EQ236
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Coasts EQ333
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Coasts EQ439
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Regeneration EQ123
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Regeneration EQ233
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Regeneration EQ335
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Regeneration EQ45
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Superpowers EQ119
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Superpowers EQ226
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Superpowers EQ316
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Water Cycle EQ133
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Water Cycle EQ230
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Water Cycle EQ331
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Carbon Cycle EQ140
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Carbon Cycle EQ2 and EQ354
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Migration EQ130
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Migration EQ221
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Migration EQ318
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Migration EQ418
