Earthquakes & Tsunami

Lesson 1: Introduction to EQ & Tsunami

Key Content

• Plate tectonics theory.
• Patterns caused by earthquakes.
• Subduction, seafloor spreading, collision zones.
• Landscape formation.
• Landscape modification.

Learning Outcomes

Students will be able to:

• Briefly outline how New Zealand was formed over time.
• Discuss the theory of plate tectonics.
• Identify the patterns formed by earthquakes.
• Use terminology correctly (eg, subduction, convection currents, tsunami, epicentre, focus, etc.).

Film Archive Footage and Key Questions

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

Shaky Beginnings (1999)

Jim Hickey astride the Murchison Falls, a product of the 1929 earthquake centred on Buller, gives a brief resume on the two big quakes of the period; Murchison and Hawkes Bay. The science of earthquakes with its particular New Zealand focus is introduced. New Zealand is sitting astride two tectonic plates (Pacific and Indo-Australian). There is a correlation between earthquake activity and plate boundaries. This explains why there are so many earthquakes in New Zealand and that they follow a long line from the south west to north east because that is the direction the plate boundary follows.

a. What did the 1929 Murchison earthquake create (as pointed out my Jim Hickey)? Waterfall.

b. How many people died in the Murchison quake? 17

c. What did New Zealand geologist Harrold Wellman help prove?
That the Earth’s crust was not static, but in fact moved. Led to the ideas about plate tectonics.

d. How many died in the 1931 Napier earthquake? 256

2. What Lies Beneath: Signs of Tsunami, Natural History NZ, 2005

What Lies Beneath (2005)

An overview of the Tsunami in New Zealand’s recent geological history. Evidence of a tsunami 500 years ago in the Wairarapa. The 1960 tsunami at Lyall Bay following a quake off the coast of Chile. The massive 1855 Wairarapa Eartquake produced a Tsunami with ten metre waves rushing over the Rongotai isthmus and back onto where downtown Wellington now is.

a. What is a tsunami?
A massive wave/rush of water that is caused by an underwater earthquake.

b. There is evidence to suggest that a tsunami hit the Wairarapa coast how long ago? 500 years.

c. In what part of Wellington did crows gather to watch a tsunami hit in 1960? Lyall Bay.

3. Murchison Earthquake Scenes June 17 1929 (extracts), L Inkster, 1929

Murchison (1929)

Scenes of the aftermath of the Murchison earthquake. Includes shots of the hospital, twisted railway lines and the Westport Post Office ruins. Seventeen people were killed in the Murchison earthquake. If the earthquake had occurred in a more populated area it could well have been one of New Zealand¹s biggest ever natural disasters.

a. What effect did the quake have on the railway lines? It twisted them.

4. Views of Murchison after the Earthquake Filmed By a Wellington Visitor (extracts), [1929]

Murchison (1929)

The aftermath of the earthquake which struck Murchison and surrounds on June 17, 1929. Shows the building damage, road washouts, collapsed bridges and the struggling inhabitants of the stricken area. This illustrates the economic effects of the hazard, as the cost of repairing the infrastructure is very high. The difficulties of dealing with road washouts, building damage etc. also puts considerable stress on the population.

a. Outline some of the economic effects of the earthquake. Rebuilding costs, shops/post offices/services etc cease trading, cost of repairing infrastructure eg. bridges.

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