Hazards

Question 1

What is a Natural Hazard

Answer 1

potential threat to human life or property caused by a natural process

Geophysical - earthquake, eruptions, landslide, tsunami

Atmospheric - storms, drought, temp, wildfire

Hydrological - flood, avalanche

Question 2

Perception of Hazard

Answer 2

wealth - afford to move or withstand - smaller risk

education - understanding, reduce risk or mitigate

past experience - used to them

Question 3

Responses - Park Model

Answer 3

Pre disaster-before is normal

Disruption- during/directly after- death/destruction

Relief(hours/days)- rescue, saving, preventing further damage

Rehabilitation(days/weeks)- resolve longer term problems/temporary shelter and aid

Reconstruction(weeks/years)- rebuilding to same standard (normal) or higher (improves)

Question 4

Responses- Hazard management cycle

Answer 4

Mitigate - minimise impacts of future disasters

Preparedness - planning responses/warnings

Response - reaction

Recovery - area back to normal

cycle as hazards are ongoing

Question 5

plate margins

Answer 5

Constructive - move apart
earthquakes and volcanoes
land forms- ocean ridge, rift valley, fault lines

Destructive - towards
earthquake and volcanoes
ocean<->continental - fold mountains and deep sea trench
ocean<->ocean - deep sea trench and island arcs(form by eruption)

Conservative - slide past
earthquake
fault lines

Question 6

Volcanic Hazards (primary)

Answer 6

Pyroclastic Flows(nuée ardente) - hot gas, ash, volcanic rock flows. high speed(80kph) long distance(15km)

Lava Flows - relatively slow

Volcanic Gases - co2 and sulfur dioxide

Pyroclastic/Ash fallout - ejected from eruption
Heavy (rock) deposits close lighter (ash) further away

Question 7

Volcanic hazards (secondary)

Answer 7

Mudflow - volcanic material mixed with water (rain or melted ice). Fast flow +80kph

Acid Rain - volcanic gases react with water vapour forming weak sulphuric acid

Question 8

Seismic Hazards

Answer 8

Tsunamis - large waves triggered by underwater earthquakes

Landslide/Avalanche - happen instant or after (loosen ground water can enter)

Soil Liquefaction - vibrations cause it to act like liquid (buildings/cars sink) hardens again after.

Question 9

Tropical storm

Answer 9

formation - 5°-20° N/S due to coriolis effect week at equator. deep water 27°C

hazards - high wind, storm surge, heavy rain, flooding, landslide

Question 10

Wildfires type/condtion/cause

Answer 10

Ground fire- ground burns, slow, no flame, no smoke
Surface fire- leaf litre/low vegetation burns, low or high intensity
Crown fire - moves rapidly through canopy

Condition - vegetation type(thickness and oily), fuel characteristics(fine/dry), climate(warm/dry/wind), behaviour(creeping/runnng and burning debris)

causes - fuel, oxygen, heat source —>natural (lightning/volcanoe) human(accident/arson)