Taranaki Blowout

The fictional eruption scenario that unfolds on this page is based on advice from volcanologists and other experts.

Taranaki Blowout logo. Click to go to Blowout home page. Follow the six-week scenario to find out what you can do right now to be ready for the day when our hypothetical event becomes a reality.

Scroll down this page to follow the scenario, or use the links below to click from week to week. If you're a business operator or school teacher, click on the links in the navigation panel at right for information and resources relevant to you.

Taranaki Blowout was run as a community exercise during September and October 2010, with thousands of people taking part. That's not the end of the story, however — the information and advice on these pages can be used at any time.


Week 1 Week 2 Week 3 Week 4 Week 5 Week 6

It all starts with some small shudders

What happens in Week 1

The seismograph network in Taranaki records a slight increase in seismic activity. There is a series of moderate main shocks and aftershocks in the Cape Egmont fault belt, and a few small, deeper earthquakes under the volcano.

What this means

Taranaki has hundreds of earthquakes a year, most not felt by the public. Of itself, a small increase is interesting but of no major concern. Volcanologists pay particular attention to earthquakes right under the mountain, as they may indicate that magma is on the move. However, there's no evidence of that yet.

The Week 1 seismic activity prompts a routine systems check and review of plans at the Taranaki Emergency Management Office on Marsland Hill in New Plymouth, which is the nerve centre during any Civil Defence emergency response in the region. The operator of the seismograph network, GeoNet, asks the public to use its online "felt quake" form if they experience any earthquakes.

What you'll see or experience

You feel one or two of Week 1's earthquakes. They'll be a topic of conversation at morning tea or around the dinner table.


Background information on Week 1 events


Geonet's Taranaki monitoring


Geonet "felt quake" online form


Taranaki Emergency Management Office

What to do in Week 1

If you are aware of the hazards and emergencies that could occur, and if know what to do and practice in advance, you'll be able to care for your family or household better in an emergency. Each week during Taranaki Blowout, we'll look at how you can do this.

You can begin by learning what emergencies could occur in your community and what your risks may be. You should be prepared wherever you may be and learn steps you can take to prevent or avoid disasters:


Volcano hazards — near-vent and distant


Volcano hazard map


NZ Hazardscape: volcanoes (314 KB)

Week 1's action list:
tick. Discuss the types of emergencies or hazards that could affect your community or household.
Graphic showing volcanic hazards. Click for large version.

tick. Discuss and learn about Mount Taranaki and the different types of hazards which will result from a volcanic eruption (see links panel above and diagram at right).
tick. Find out how your home could be affected by a volcanic eruption. Check out the volcanic hazard map for Taranaki which shows areas that could be affected by volcanic hazards (see links panel).
tick. Check that your household insurance is sufficient and up to date and that all of your important documents are in a safe place.
Click on diagram at right for large version
Download a PDF of the diagram (140 KB)


And the shakes go on ...

What happens in Week 2

Large landslides at the headwaters of the Stony River. Earthquake activity declines in the Cape Egmont fault belt, but irregular swarms of quakes continue under the volcano.  Some are felt by the public and are reported via GeoNet.

Two large landslides are reported along Pyramid Stream at the headwaters of the Stony River (see picture at left).

Landslips aren't uncommon in this erosion-prone area, but these ones are assumed to be caused by the ground shaking.

What this means

Because earthquakes are occurring right under the mountain, the volcanic alert level is raised from 0 to 1, signifying initial signs of possible volcano unrest but no eruption threat. GeoNet continues to monitor the mountain.

What you'll see or experience

More earthquakes are felt and some have the potential to cause damage by knocking items off shelves, for example.

 Minor landslides occurr and may cause minor traffic disruption in areas close to the mountain. 

 Rumours begin to spread as some people grow more concerned.


Background information on Week 2 events




Volcano alert levels

What to do in Week 2

Much of the risk of damage caused by earthquakes can be eliminated by taking precautions, planning and practising what to do.

The Earthquake Commission website has useful links on ways to quake-safe your home and the "drop, cover and hold" earthquake drill. See links panel below.

 This week, get your family or household together and agree on a Household Emergency Plan.

 A plan will help you respond safely and quickly when a disaster happens. Families may be separated when a disaster happens.

Emergency services will be affected and travel and communications may be interrupted. Plan and practice an evacuation plan and be prepared to shelter-in-place.

To help you get started, download and print the Household Emergency Plan template (see links panel below) and work as a team to complete the simple checklist below.


Quake-safe your home

Earthquake drill: Drop, cover and hold


Taranaki radio frequencies


Household Emergency Plan template


Advice for people with disabilities

Week 2's action list:
tick. Decide where to shelter in your home.  Draw this on a plan of your house
tick. Decide how and where you will meet up during and after a disaster, including one in which you have to leave your neighbourhood.
tick. Decide where you'll store emergency survival items and who's responsible for checking them.
tick. Make arrangements for household members that may have a disability or special requirement. See links panel above for advice.
tick. Know what to do if you have to evacuate your home - take your Getaway Kit and essential emergency items, and turn off water and electricity at the main switches. Turn gas off only if officials advise you to.
tick. Decide what you will need to do for pets and livestock.
tick. Add an "ICE" (In Case of Emergency) number to the contact list in your mobile phone.
tick. Record emergency contact numbers - emergency services (111 if life is threatened), Civil Defence (0800 900 049), neighbours or other contacts.
tick. Record the frequency of the official Civil Defence radio station that you'll tune to for information — see the links panel above for our list of Taranaki frequencies.
tick. Draw a plan of your house showing places to shelter, exits, assembly areas, emergency survival items and where to turn off water, electricity and gas.
tick. Check that your insurance is adequate and up to date.


Is it going to blow? When?

What happens in Week 3

Irregular swarms of earthquakes continue to be recorded by GeoNet under the volcano, and are reported via the web page.  There are indications that the quakes may be getting shallower

Heavy rain on the north-western side of the volcano triggers large landslides into the Stony River. Trampers report the landslides to media. Some of Egmont National Park's walking tracks and walkways are damaged by ground movement.

What this means

While public interest and concern are now high, the Volcano Alert Level still remains at 1 ("possible volcano unrest but no eruption threat"). Scientists still need more conclusive evidence that an eruption may be on the way.

At this stage they can not be sure whether the current level of activity will last for another five weeks, five months or five years, or whether it will die out or lead on to an eruption.


Background information on Week 3 events

What you'll see or experience

Briefing session at the Taranaki Emergency Management Office. The regional media will be running hot with stories and comments, some misinformed, and the activity on the mountain will be the No 1 topic of conversation in Taranaki and big news throughout New Zealand.

The Taranaki Emergency Management Office (see picture at left) is now on permanent activation as Civil Defence responds to media inquiries by highlighting the advice and information received from specialist volcano advisers. Behind the scenes, Civil Defence's welfare, essential services and rural advisory groups are kept fully briefed and prepared.

As GeoNet continues its montoring, it keeps Civil Defence informed about potential high-risk areas, so that evacuation plans can be made.

Civil Defence also consults its Taranaki Volcano Scientific Advisory Group, a panel of experts drawn from agencies and universities, about specific questions and concerns relating to the unrest.

What to do in Week 3

Plan to be able to look after yourself and your household for at least three days or more when a disaster strikes. Assemble and maintain “emergency survival items” for your home. You should also have essential items in your workplace and in your car.

 Store emergency survival items in portable containers where they can be easily accessed and near an exit.


Household emergency checklist


Tips for storing water


Items for first aid kit

You can use some items for everyday use but make sure you replenish them and can find them quickly in an emergency. To help you get started, work through the checklist below as you assemble your household's emergency survival items.

This week's action list:
tick. Torch with spare batteries, or a self-charging torch.
tick. Radio with spare batteries.
Check all batteries every three months. Battery powered lighting is the safest and easiest. Do not use candles as they can tip over in earthquake aftershocks or in a gust of wind. Do not use kerosene lamps, which require ventilation and are not designed for indoor use.
tick. Waterproof and wind-proof clothing, sun hats and strong outdoor shoes.
tick. First aid kit and essential medicines.
You can buy ready-made first aid kits or make up your own. See the links panel above for a list of recommended items. First aid training will be invaluable in a disaster so consider taking a first aid course.
tick. Blankets or sleeping bags.
tick. Pet supplies.
tick. Toilet paper and large rubbish bags for your emergency toilet.
tick. Face and dust masks.
Food and water for at least three days:
Check and replace food and water every 12 months. Consider stocking a two-week supply of food and water for prolonged emergencies such as a pandemic. See links panel above for tips on storing water.
tick. Non-perishable food (canned or dried).
tick. Food, formula and drinks for babies and small children.
tick. Water (at least three litres per person per day) for drinking.
tick. Water for washing and cooking.
tick. A Primus stove or gas barbecue to cook on.
tick. A can opener.


Threat confirmed, emergency declared

What happens in Week 4

A state of emergency is declared in Week 4. Earthquakes continue to increase under the mountain, and are becoming shallower.

Trampers still on the mountain report that the water smells like sulphur.

Roads are closed to the west of the mountain. The Continuous GPS monitoring reveals minor indications of ground movement - enough to cause a major rockfall in the headwaters of the Stony River, partially damming it with debris.

Already the bed of the Stony River is up four to five metres and the Blue Rata Reserve is flooded. The western side of the mountain is the most prone to erosion at the best of times. Add volcanic rumblings to this unstable geology and you can expect something to give.

Sure enough, the rockfall dam bursts, sending debris rushing downstream, taking out the Wiremu Road bridge and damaging the gas pipeline. Further downstream, low-lying land near the SH45 bridge is covered with flood deposits. Many roads are impassible in that area.

What this means

GNS Science determines that the earthquakes are defintely volcanic in nature, indicating the movement of magma. The Volcanic Alert Level is raised to 2: "Confirmation of volcanic unrest. Eruption threat." Civil Defence declares a local state of emergency.


Background information on Week 4 events


Precursors to an eruption


Volcano hazard map

What you'll see or experience

On the western side of the mountain near the Stony River, evacuation begins as soon as reports come in that the upper Stony is dammed by debris. Thankfully, there are no casualties when the rockfall dam bursts and thousands of tonnes of debris came tumbling down the river. However, there are stock losses. Access to Coastal Taranaki is impossible from the north.

People living alongside all rivers flowing from the mountain and in other potential eruption hazard zones (see links panel for map) are advised they should prepare themselves to evacuate at short notice. The mountain is now the No 1 news topic in New Zealand and Australia.

What you and your household can do right now ...

You always need to be ready in case you need to evacuate in a hurry. Everyone should have a packed getaway kit in an easily accessible place at home and at work. To help you get started, work through the simple checklist below as you assemble a getaway kit.

Don't forget, you will also need to consider how you will care for your pets during an evacuation.


Taranaki Welfare Centres


Taranaki radio frequencies


Advice for people with disabilities

This week's action list — assemble your getaway kit using the following items:
tick. Torch and radio and spare batteries.
tick. Any special needs such as hearing aids and spare batteries, glasses or mobility aids.
tick. Emergency water and easy-to-carry food rations such as energy bars and dried foods in case there are delays in reaching a welfare centre or a place where you might find support. If you have any special dietary requirements, ensure you have extra supplies.
tick. First aid kit and essential medicines.
tick. Essential items for infants or young children such as formula and food, nappies and a favourite toy.
tick. Change of clothes (windproof and waterproof clothing and strong outdoor shoes).
tick. Toiletries — towel, soap, toothbrush, sanitary items, toilet paper.
tick. Blankets or sleeping bags.
tick. Face and dust masks.
tick. Pet supplies.
tick. Important documents.
Include identification documents (birth and marriage certificates, driver's licences and passports), financial documents (for example, insurance policies and mortgage information), and precious family photos.

If you've been following Taranaki Blowout since week 1 you should now have:

  • Household emergency plan
  • Emergency survival items
  • Getaway kits

If you haven't, then use the checklists from previous weeks to prepare them:

Week 2 — Household emergency plan

Week 3 — Emergency survival items

... and what to do when a real eruption threatens

tick. Listen to your local radio stations for advice from Civil Defence and other agencies. (See links panel above for list of Taranaki frequencies).
tick. Put your emergency plan into action.
tick. Check your plans for sheltering in place at home.
tick. If you are in a high-risk area, talk to friends and relatives both in your neighbourhood and outside the area about arrangements if you have to evacuate quickly.
tick. Organise evacuation routes and transport arrangements.
tick. Know where your nearest Emergency Welfare Centres are (see links panel above).
tick. If you have a disability or need assistance, make contact with your support network and follow Civil Defence advice. See links panel for advice.
tick. Put all machinery inside a garage or shed, or cover with tarpaulins, to protect them from volcanic ash.
tick. Bring animals and livestock into closed shelters, if possible, to protect them from volcanic ash.
tick. Protect sensitive electronic equipment and do not uncover until the environment is totally ash-free.
tick. Ashfall may affect water supplies, so check your drinking-water supplies and fill bathtubs and sinks with water.
tick. Check on friends and neighbours who may require special assistance.



Eruption! Eruption!


What happens in Week 5

The continuous GPS monitoring equipment detects a bulge on the western side of the volcano.

Volcanologists fly near the mountain in a helicopter equipped with a thermal imaging camera. They detect hot spots that may be fumaroles but the cloud cover forces them to retreat with little more information.

Fumaroles are steam-fed features, formed as groundwater becomes super-heated to steam by the heat of the rising magma below. As this super-hot steam reaches the surface, it can generate small eruptions, creating small pits and craters.

 Soon loud booms are heard as more fumaroles are created. Then a new larger vent opens near the summit with loud booms, and the first eruption occurrs with an explosion heard throughout the region. As a hot rock avalanche spews down the slopes of the mountain towards the headwaters of the Stony River, snow and ice melts instantly and pours into the rivers and streams on the western and southwestern side of the mountain.


Background information on Week 5 events






Pyroclastic flows

A second eruption shortly afterwards sends steam and ash 5 km into the air before raining down on the upper slopes. The hot material instantly melts snow and ice and this drains into the Waikwhakaiho and Kapuni Rivers, generating floods which damage their banks in places.

Then a third eruption sends a plume of steam and ash 5 km into the air, where it begns drifting towards the south-east.

The effect of lahars on the Waiwhakaiho Valley? Hot rock tumbles down the north-eastern flank, crushing vegetation and setting it alight. Ash mixed with water and boulders loosened by the eruptions continues to feed into the Waiwhakaiho River, and a lahar reaches as far as Lake Mangamahoe.

As the clouds clear, a small lava dome become svisible near the summit. Every 15 minutes or so, avalanches of hot rock tumble down the upper slopes from the steep margins of the new dome.

Gradually, the explosive activity dies down until the late afternoon, when a 4.7 magnitude earthquake shakes the whole region. This appears to set off two violent eruptions, sending a plume of ash and steam 12 km into the air.

This results in a deadly and awesome display of what scientists call pyroclastic flows. The dense eruption columns are made up of of magma, rock and ash that is searing hot. As these collapse under the pull of gravity, they drop to the upper slopes forming volcanic landslides, or pyryclastic flows. These are part-solid, part-liquid, part-gaseous clouds heated to hundreds of degrees. They race down the side of the mountain at speeds of up to 200 kmh, obliterating everything in their path for 7 km to 10 km.

These pyroclastic flows are seen reaching The Turtle, Pyramid Track, Big Pyramid and Puniho Hill. A smaller one is also seen at the base of Carrington Ridge.

Meanwhile, another lahar sweeps down the Waiwhakaiho River to the water treatment station at Lake Mangamahoe.

What this means

The Volcanic Alert is quickly raised to 3  ("Minor eruptions commenced. Real possibility of hazardous eruptions.") then 4 ("Hazardous local eruption in progress."). The bulge forming on the western slopes is a signal for evacuation of the 70-odd houses bounded by the Stony River, Wiremu Road, Punehu Stream and the Egmont National Park boundary before the eruption develops. Civil Defence Emergency Welfare Centres are opened at Manaia and Rahotu for around 200 displaced residents.

When snow and ice is rapidly melted by the eruption and comes flooding down the western side of the mountain, bridges on Wiremu Road are destroyed and Opunake loses its water supply. The Stony River, Okahu, Warea and Oaonui Streams, the Waiaua River and the Mangahume and Punehu Streams all burst their banks within the hour. Up to 8000 ha of farmland is either inundated or cut off by floodwaters.

However, bridges on SH45 south of Opunake remain intact, allowing a fleet of tankers to bring water to the town.

Elsewhere, the first rush of ice and snow melt along the Waiwhakaiho and Kapuni Rivers brings the evacuation of some houses close to the river banks. The occupants were advised well in advance that this may be necessary.

Then the Waiwhakaiho gets its first lahar. The intake gates at the Lake Mangamahoe water treatment plant are closed to prevent contamination of the water supply for New Plymouth District's 70,000 people, and the whole district is immediately put on water restrictions.

The second lahar in the afternoon tests the intake gates, but they hold. However, water supply is emerging as a major issue as resources are managed during the eruption.

View video of lahar in Indonesia

Stratford and South Taranaki experience relatively light ashfall - only around 1 mm - as the morning's plumes drift slowly to the south-east. This is enough to discolour some smaller water supply sources.

It could also threaten the safety of aircraft and cause minor damage to aircraft, vehicles, equipment and houses, as well as irritate lungs and eyes and affect road visibility and traction.

What you'll see or experience

Many of the eruptions will be heard throughout the region. If you live along or above Wiremu Road between the Stony River and Punehu Stream, you'll have to evacuate your home. People living close to the banks of the Waiwhakaiho and Kapuni Rivers may also have to evacuate. If you're in Opunake you'll have had no tapwater and will have to get your supplies from tankers at the roadside.

Residents throughout the region are asked to restrict their use of water. In those areas affected by ashfall, schools are closed and people are advised to stay indoors and off the roads.

What to do during a volcanic eruption

A volcanic eruption will produce a wide variety of hazards that can kill people and destroy property. Study the advice below and discuss it with your family.

If you or any members of your household have a disability, see the link below for advice on measures you can take.


Ashfall Guidelines (425 KB)


Taranaki radio frequencies


Advice for people with disabilities

To help protect you and your family during a volcanic eruption:
tick. Take turns listening for short periods to the radio or TV for Civil Defence advice, and follow instructions. See Links panel above for radio frequencies.
tick. If outside at the time of eruption, seek shelter in a car or building. If caught in volcanic ashfalls, wear a dust mask or use a handkerchief or cloth over your nose and mouth.
tick. If the advice is to shelter at home, you should stay indoors. Volcanic ash is a health hazard, especially if you have respiratory difficulties such as asthma or bronchitis.
tick. When indoors, close all windows and doors to limit the entry of volcanic ash. Place damp towels at thresholds.
tick. Do not tie up phone lines with non-emergency calls.
tick. If you have to go outside use protective gear such as masks and goggles and keep as much of your skin covered as possible. Wear eyeglasses, not contact lenses, as these can cause corneal abrasions.
tick. Disconnect drainpipes/downspouts from gutters to stop drains clogging. If you use a rainwater collection system for your water supply, disconnect the tank.
tick. Stay out of designated restricted zones.
If you are in a high-risk area that is evacuated:
tick. Listen to your local radio stations for advice from Civil Defence and other authorities for your community and situation. See links panel above for radio frequencies.
tick. Evacuate quickly if told to do so by authorities. Take your getaway kit with you. If you are outside the evacuation zone when a warning is issued, do not go into an at-risk area to collect your belongings.
tick. If there is time, secure your home as you normally would when leaving for an extended period.
tick. Turn off electricity and water at the mains if there is time. Do not turn off natural gas unless you smell a leak or hear a blowing or hissing sound, or are advised to do so by the authorities.
tick. Take your pets with you when you leave if you can safely do so.
tick. If you have livestock, evacuate your family and staff first. If there is time, move livestock and domestic animals to a safer area.
tick. Use travel routes specified by local authorities. Some areas may be impassable or dangerous so avoid shortcuts. Do not drive through moving water. If you come upon a barrier, follow detour signs.


Living with a volcano

What happens in Week 6

The lava dome continues to grow and occasionally collapses.  Occasional pyroclastic flows are generated as a result.

As the weeks go on, ash and steam occasionally erupt from the mountain, generating ashfall. When it rains on the cone, the loose ash is remobilsed and lahars are generated into most of the catchments that are fed by mountain streams and rivers.

Geological records indicate that periods of violent explosions and quiet periods should be expected for one to 10 years.


Background information on Week 6 events


Ashfall Guidelines (425 KB)


Actions to take for ashfall

What this means

 The mountain continues to be a dangerous place during lava dome collapses and pyroclastic flows. These may gradually die out but the possibility of ash falls will remain and lahars will occur whenever it rains on the mountain.

What you'll see or experience

  In the short term, there may be ash fall affecting your property or workplace. Lahars and floods may damage farmland, roads and bridges, and disrupt traffic and communications. There may also be water restrictions.

Longer term, some changes may be necessary to enable us to live alongside a periodically active volcano. To get an idea of what this may entail, click on "Background information" in the links table.

What you should do in the first few days after a volcanic eruption

See the links table above to access useful information on coping with ash fall.

  • Listen to your local radio stations for Civil Defence advice and follow instructions.

  • Stay indoors and away from volcanic ashfall areas as much as possible.

  • When it is safe to go outside, keep your gutters and roof clear of ash, as heavy ash deposits can collapse your roof.

  • If there is a lot of ash in the water supply, do not use your dishwasher or washing machine.

  • Avoid driving in heavy ashfall, as ash can clog engines and cause serious abrasion damage to your vehicle.

  • Keep animals indoors where possible, wash away ash on their paws or skin to keep them from ingesting the ash, and provide clean drinking water.

  • Use a mask or a damp cloth and eye protection when cleaning up.

  • Moisten the ash sparingly with a sprinkler before cleaning up. Do not soak the ash, as it will become hard and the added weight could cause roof collapse.

  • Look for and report broken utility lines to appropriate authorities.

  • If your property is damaged, take notes and photographs for insurance purposes. If you rent your property, contact your landlord and your contents insurance company as soon as possible.

  • Residential property damage from volcanic activity is covered by Earthquake Commission (EQC) insurance provided you already have house/contents insurance.

Get ready for another eruption

  • Check your emergency kits and replace anything that's been used.
  • Update your household plan with anything you've learnt during the eruption.
  • If you have to repair your house, think about how you can reduce damage in future, eg increase the roof pitch to reduce ash buildup; if you collect water from your roof, install diverters to protect your supply.
  • Check to see if you can help others in your community who have been affected by the eruption.


What you need to be ready

If you've been following Taranaki Blowout over the past six weeks, you'll have seen our information and advice on preparing a household emergency plan,  household emergency supplies, and a getaway kit. If not, click on the links below:

Household emergency plan

Household emergency supplies

Getaway kit


Who was behind Taranaki Blowout?

This exercise was run by the Taranaki Civil Defence Emergency Management Group in partnership with New Zealand Red Cross and with input from GNS Science. Red Cross logo.
Taranaki CDEM Group - click for more info.
The CDEM Group acknowledged the support of these organisations:
GNS Science logo.
GNS Science
Ministry of Civil Defence logo.
Ministry of Civil Defence
and Emergency Management

M&O Pacific
Powerco logo.
Classic Hits 90FM Taranaki - click for website.
Classic Hits
90FM Taranaki
93.2 More FM Taranaki. Click to go to website
93.2 More FM
Methanex NZ Ltd. Click to go to website.
New Zealand Ltd
Pace Engineering Ltd - click to go to website
Pace Engineering Ltd


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