What are Extreme Natural Events?

Learning outcomes:1. Understanding the difference between an

extreme natural event and a natural

disaster.2. Explain the difference between natural

disasters and other hazards.

3. Identify natural hazards in NZ, Australia & the South-west Pacific

4. Draw and interpret a Venn diagram

Natural eventsCaused by natureOccur frequently in many

environmentsIs a result of a series of

processes.Example: The rainfall process

Extreme natural eventsOccur less frequentlyThey are natural hazards only if

they threaten people’s activities and property

Extreme natural events put people’s actions, property and resources at risk.

They are likely to modify or change environment.

A river after a flood

Examples of Extreme Natural events

Damage after a tornado

Earth quake damage

Damage after a volcano erupted

Human error vs. Extreme natural event

Ballantyne’s fire-possibly caused by electric fault

Napier fire-caused by 1931 earthquake

Important terms:Onset Period-Some natural events build

up more slowly, and give more warning, than others. A tropical cyclone has a much slower onset period than a hailstorm

Duration-Some extreme natural events last longer than others. A drought lasts much longer than an earthquake which may be over in a few seconds.

Frequency-Some extreme natural events occur less frequently than others but cause more damage when they occur.

New Zealand’s Natural hazardsNew Zealand’s environment is largely

mountainous and geologically active. It is surrounded by ocean and lies across a belt of westerly winds. Consequently extreme natural events occur frequently in New Zealand.

New Zealand’s population distribution and cultural processes (eg. farming, urbanisation) expose it to a range of natural hazards.

Natural hazards in New ZealandFlooding EarthquakesVolcanic Eruptions LandslipsTornados Coastal erosion

Bush firesCyclones Blizzards

Thunderstorms Hailstorms Droughts

Australia’s Natural HazardsAustralia’s natural and coltural

environments are different from New Zealand’s

Natural hazards in Australia include droughts, bush fires, tropical cyclones and floods

Different parts of Australia are affected by different natural hazards

South–west Pacific Islands natural hazardsThe islands of the South-west Pacific

have different natural and cultural environments from both New Zealand and Australia.

They have a tropical climate, are surrounded by ocean, and consist mainly of small volcanic islands and coral atolls.

The most common extreme natural events are tropical cyclones, earthquakes, volcanic eruptions, tsunamis and droughts.

Now consolidate your learning through completing the following activities:

1. Venn Diagram activity 2. Learning Activity