New Zealand Disasters

Lesson 2: Volcanoes

Shaky Beginnings (1999)

Key Content

• Mt Tarawera Eruption 1886
• Mt Ruapehu Eruption 1996
• Tangiwai Disaster 1953

Learning Outcomes

Students will be able to:

• Briefly outline the sequence of events in a volcanic eruption.
• Describe the effects of a volcanic even on people and the land.
• Describe how people can increase or decrease the effects of a volcanic event.

4. Tarawera 1886 – Extracts from Vulcanism 2006, Messenger Films, 2001

Tararewa, 1886

Primary source material, computer graphics and static images are woven together to tell the Tarawera story. Big focus on the Pink and White Terraces.

a. What natural feature was considered to be the eighth wonder of the world at the time of the 1886 eruption?
The Pink and White Terraces.

b. How was this natural feature formed?
Hotpools discharged water down hill. The water contained ilica – silica built up over 100s of years to form the terraces.

c. What was the first sign of an impending eruption?
The water in the lake had gone.

d. What caused the most damage to people and the land during the eruption?
The lake bed split and the water went into the magma chamber underneath where it was superheated. The steam exploded and dumped boiling mud over a wide area.

e. Do you think there are more risks to humans and property now than in 1886?
Yes because there are many more people near the mountain and more buildings near there than what there was in 1886.

5. Shaky Beginnings (extract), Bryan Bruce Productions, 1999

Shaky Beginnings (1999)

Jim Hickey starts with the volcanic plateau, talks about Ruapehu and lahars and introduces the Tangiwai scenario. Jim Hickey studied Geography at Victoria University and was once a Geography teacher before becoming a TV weather man.

a. What is a lahar?
They are a flow of water, ash and mud and are a by-product of volcanic processes. The can build the landscape (eg . the ring plains around the mountains). As the footage shows they can also be very destructive. This begs the question, should Tranzrail still be using the same route across the lahar prone Whangaehu River and other rivers near by?

6. The Truth About Tangiwai (extracts), Top Shelf, 2002

The Truth About Tangiwai (2002)

The Truth About Tangiwai is the story of a disaster that should never have happened. The scientific and geographic background to the events are highlighted.

a. What could have been done to prevent the disaster?
Building bridges on more suitable ground; proper bridge maintenance; heading warnings from geologists and mountaineers. Today there is a comprehensive network of lahar warning systems in place. These include seismographs and trip wires that run across potential lahar routes (eg. on ski fields) that set of alarms.

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