Tectonics

Hazard Profiles:

-Size                          -Duration

-Predictability            -Spatial extent 

-Frequency                -Speed of onset 

-Duration 

modifying the event ; zoning, building proofing 

modifying the vulnerability; education, preparation & preparedness

modifying the loss; aid, insurance 

Disaster aid:

via governments, NGOs & private donors for relief, rehabilitation and reconstruction 

appropriate for middle/lower income countries

International governmental aid 

used in emerging/developed countries by spreading financial load through tax payers 

key players:

Aid donors 

emergency aid such as food, water, shelter

Communities

search & rescue, rebuilding communities & improving resilience 

Insurance 

help recovery by providing money for repairs 

Non-Governmental organisations 

help when governments lack funding, help develop reconstruction plans for safer future 

HILP Event: High impact, Low probability 

Mega Disaster: +2000 deaths 

+200,000 homeless 

GDP reduced by 5% or dependence on aid for 1 year 

geophysical hazard: caused by physical processes acting upon, above or within the earth e.g.

earthquakes, volcanoes & tsunamis 

hydro-meteorological hazard: caused by water, weather or both e.g. 

floods, storms & droughts 

Physical & environment 

high population density, poor housing quality (more vulnerable) caused by rapid urbanisation 

Government & political 

poor, inneficient services mean slower recovery, corruption leads to resouce exploitation

Economic 

less money for aid and resources such as proofing etc 

Social 

lack of education means unaware of risk, poor healthcare, vulnerable people unable to survive 

500 deaths = disaster

what determines the severity of a hazard?

-size                                  -regularity

-number of hazards.         -predictability 

-location                            -magnitude 

-frequency                         -duration 

three earthquake scales:

Mercalli (I-XII)

Richter (0-9)

Moment Magnitude scale  (measures energy release)

Industrialised countries 

-higher short term economic loss 

-buildings are proofed, have warning systems 

-have immediate relief & emergency medics 

-property insurance 

Developing countries 

-long term economic & social development drawbacks 

-lack or resources 

-higher number of casualties (population density)

-lack of funding 

P waves = primary waves 

S waves = secondary waves 

Surface waves = move along surface after P&S

Love waves = move side to side 

Raleigh waves = move up and down 

destructive: ocean trenches, fold mountains, tsunamis, earthquakes 

constructive: ridges, rift valleys, volcanoes  

conservative: faults  

hot spots: volcanoes occurring in the middle of a plate, not at the boundary 

Gentle, Basaltic Lava 

higher temperature, lower viscosity, shield volcanoes 

Moderate,Andesitic Lava  

composite volcanoes, medium temperature 

Violent, Rhyolitic Lava 

lower temperature, higher viscosity, composite and supervolcanos 

Measuring volcanoes: seismology, volcanocams, gas analysis, ground deformation 

Prediction: easier than an earthquake, but still difficult, watch for gas release and crater bulging 

Volcanic effects: Lava flows, Pyroclastic flows, Tephra, Ash fall & Gas eruptions 

After shocks 

smaller earthquake shocks after the earthquake caused by sudden change in stress 

Ground shaking 

caused by passage of seismic waves near surface and epicentre 

Crustal fracturing 

cracking/seperation in geological formation that divides the rock 

natural event: event in an isolated place 

natural hazard: potential risk to population 

natural disaster: event that impacts population 

hazard vulnerability: the capacity a person or group has to anticipate, cope with, resist & recover from the impact of a natural hazard 

why do people remain exposed to hazards?

-unpredictability

-lack of alternative e.g. poverty

-changing levels of risk e.g. sea level rise 

-cost vs benefit e.g. fertile soils