Vulcanism

Lesson 4: Volcanoes & Human Activity

Mount Ruapehu, 1995. Shaky Beginnings (Bryan Bruce Productions, 1999)

Key Content

• The Tangiwai Disaster.
• The 1996 Ruapehu eruption.
• Auckland’s volcanic field.

Learning Outcomes

Students will be able to:

• Outline the sequence of events that occurred leading up to the Tangiwai disaster.
• Discuss the hazards posed to humans by volcanoes.
• Describe how humans can plan for and mitigate the effects of hazardous volcanic events.
• Use terminology correctly (eg, lahar, volcanic field, fire fountain).

Relevant Film Archive Footage and Key Questions

10. The Tangiwai Disaster (1953) Shaky Beginnings

Shaky Beginnings (1999)

Jim Hickey studied Geography at Victoria University and used to be a Geography teacher before becoming a weather man.

a. What is a lahar?
They area volcanic mud flow of water, ash and mud. Lahars 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?

11. The Truth About Tangiwai

IThe Truth About Tangiwai (2002)

The PH level at the Tangiwai site is about three. This means that there is quite a bit of sulphurous acid in the river coming of the mountain.

a. Why do you think so many of the earlier warnings about a potential disaster at Tangiwai went unheeded?

b. 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.

12. Ash Monday

Ash Monday (1996)

a. How humans have been affected by the ash from the volcanic eruption? Identify at least three points. eg. Ash on cars, damage to paintwork, poor driving visibility, air traffic problems, taste of ash in mouth.

13. Auckland Shaky Beginnings

Auckland in Shaky Beginnings (1999)

Auckland is on a volcanic field. Basalt volcanoes come from basic magma that rises to form magma chambers near the surface. The subsequent eruption produces very liquid lava, or, if gas is released, lava fountains.

a. What is the statistic that may worry Aucklanders?
A 3 % chance that in the next 100 years a new volcano could break through somewhere in the city.

14. Landmarks: A Land Apart

Landmarks: A Land Apart (1981)

a. Why do you think Auckland was built on a cluster of volcanoes?

b. What impacts on Auckland (and indeed NZ) would there be when a new volcano breaks through in Auckland city?

c. Do you think Aucklanders are as concerned or informed about an inevitable volcanic disaster happening in their city as Wellingtonians are about earthquakes?

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