Effects of an Extreme Natural Event in New Zealand: Napier Earthquake

1. Choose an extreme natural event in New Zealand which you have studied. Describe in detail how ONE natural process that occurs above OR below the earth’s surface produces your selected extreme natural event. You may answer in paragraph form or use a combination of diagrams and notes. Plate tectonics – the earth’s crust is made up of a series of giant plates which float on the molten mantle. Convection currents in the mantle cause the plates to move – converging, diverging, sliding and subducting. Pressure builds up along fault lines and when it is released it causes an earthquake. Foreshocks may occur – an indication that rocks are at breaking point. Cultural processes – people choose to live in earthquake prone zones e.g. fertile soil, beautiful landscape.

2. Choose an extreme natural event in New Zealand which you have studied. Describe in detail the effects on the earth’s surface of your selected extreme natural event. Specific references to a named case study (or studies) must be included in your answer. Main shock occurs. Rocks fracture or slip along the existing fault line e.g. Napier earthquake – stress had been building up as the Pacific Plate subducted under the Indian-Australian Plate. Magnitude 7.8. Shaking is felt as soon as seismic waves reach the surface. P Waves bring the first shock, but most shaking often comes with the S Waves or Surface Waves. The shaking may last for seconds or minutes e.g. Seismic Waves shook Napier for two minutes. Sudden and dramatic effects. Direct effects – ground movement. Secondary effects – effects caused by the ground movement. Stressed rocks crack and dilate causing the surface to tilt or bulge. Faults can move laterally, which pulls the rocks apart and creates fissures e.g. Napier – fault moved 6m. Vertical movement causes scarp faces e.g. Napier - fault moved 7m. Maximum uplift was 2.7m and caused Napier’s tidal Ahuriri Lagoon was raised out of the sea. Continued vertical movement causes horsts and grabens e.g. Mt Cook and the Southern Alps. Liquefaction – loose soils behave like liquid. Landslides – on unstable hills e.g. Napier. Tsunami – when the sea floor rises or falls. Seiches – waves which move back and forth e.g. Wellington harbour. Left-lateral / Right-lateral – causes streams to be offset.

3. Briefly describe TWO actions people can take before the event and TWO actions people can take after the event to DECREASE the effects of your selected extreme natural event. Specific references to a named case study (or studies) must be included in your answer. BEFORE: 1.) Strict building codes needed to prevent catastrophic damage. Napier – central town was devastated. Brick and concrete buildings were most severely damaged and only 3 were left standing. Broken gas pipes started fires so wooden buildings were also destroyed. 2.) Emergency plans needed so people know what action to take during and after the extreme natural event. Napier – many people were killed when they ran outside in panic and buildings fell on them. AFTER: 1.) Napier – within a few hours navy ships with relief supplies and workers were sent from Auckland. Restoring essential services and repairing homes were their first priority. 2.) Napier – businesses were assisted with a government loan which paid for a temporary “tin town” shopping centre for 54 shops. However, many businesses did not recover.

4. In the space below, describe the human response both during and after the extreme natural event you selected. Specific references to a named case study (or studies) must be included in your answer. Human response during the event: Immediate Response – The earth moves and severe shaking of the ground is felt as seismic waves radiate from the focus. People often respond to this by standing under door frames or sheltering under tables or desks. Others leave buildings as rapidly as possible, however, there are also people who respond by panicking and placing themselves in further danger. Napier – people ran out into the streets and were crushed by falling masonry. Emergency Response (days) - Civil Defence Emergency is declared. Emergency services put out fires, search for survivors and treat the injured. Search and rescue teams use specialist equipment e.g. dogs. Transport routes are re-established. Field hospitals are set up. Evacuees are sent to Evacuation Centres and security forces keep people out of the evacuated areas to prevent further loss of life and looting. Aftershocks are a continuing threat. Napier – 674 aftershocks in the following moths, some of them large.

5. In the space below, describe the human response both during and after the extreme natural event you selected. Specific references to a named case study must be included in your answer. Human response after the event: Clean Up & Assessment (weeks) – Government assesses damage in order to establish what assistance will be needed. Napier – damage was estimated at $10 million in 1931, which is $900 million today. Weakened buildings are demolished. Lifelines e.g. water, electricity, are restored. Repair (months) – Counselling, Insurance claims. Some evacuees may return home. Some businesses reopen. More services restored. Recovery (years) – If the earthquake was in a major centre the economy may be affected for years. Repair of major infrastructure may take years. Tourism may be negatively affected as news reports make tourists stay away. Napier – became a tourist attraction because it was rebuilt in the distinctive 1930s art deco style. Disaster plans are re-evaluated. Napier – building codes were re-written.

6. Describe TWO social and TWO economic effects on the community of this extreme natural event. Specific references to a named case study must be included in your answer. SOCIAL EFFECT ONE: Loss of life. Napier – 161 people were killed in Napier and another 95 elsewhere in the Hawke’s Bay. Many were killed when they ran outside in panic and buildings fell on them. Others, trapped in buildings, died in the fires which followed the quake as a result of broken gas pipes. Firefighting was impossible as a result of broken water pipes. SOCIAL EFFECT TWO: Loss of homes and property. Napier – hospital was badly damaged and had to be evacuated. A tent field hospital was set up on a racecourse. A refugee camp was set up in a park and other camped on the beach or in their gardens. Building codes had to be re-written after the earthquake.

7. Describe TWO social and TWO economic effects on the community of this extreme natural event. Specific references to a named case study must be included in your answer. ECONOMIC EFFECT ONE: Local economy is damaged. Napier – damage was estimated at $10 million in 1931, which is $900 million today. Businesses had to be assisted with a government loan which paid for a temporary “tin town” shopping centre for 54 shops. However, many businesses did not recover. ECONOMIC EFFECT TWO: Jobs can be lost or created. Napier – some benefits were brought because the once cramped city was able to expand onto land raised out of the harbour. Napier airport and the suburb of Marewa were built, so builders were needed.