Mount Tongariro Erupts, Ash Cloud Heading East – updated

New Zealand’s volcanoes are still active

The North Island’s Mount Tongariro (Mount Doom of the Lord of the Rings movies) has erupted and an ash cloud is headed east. Ash deposits were later found to contain Fluorine which is  toxic and often used in pesticides (including 1080: Sodium monofluoroacetate)

If further falls of greater than 2 mm (0.08 of an inch) are deposited on farmland “ a significant agricultural hazard can be anticipatedsource

Scientists are saying that the activity could continue for months, even years after the volcano had lain dormant for almost 100 years.

Civil Defence has said that volcanic activity may threaten Waikato, Hawke’s Bay, Gisborne, Manawatu-Whanganui, Bay of Plenty and Taranaki. People living in those areas have been advised to stay indoors with all the windows and doors closed and listen to the radio for updated emergency information and instructions.

Despite the volcano showing signs of increasing activity over the last few weeks and the raising of alert levels, NZ scientists are claiming the eruption came as a “total surprise.”

Last night’s eruption was a total surprise, so “we have to expect the unexpected”, GNS volcanologist Michael Rosenberg said.

The mountain erupted at 11.50pm, sending ash across roads and prompting a potential threat warning for central North Island regions.

The eruption threw rocks and spewed ash from the Te Mari craters, near Ketetahi hot springs, on the northern side of the mountain, GNS Science said”

Eyewitnesses told reporters what they’d seen

Truck driver Tama Coker was heading across the Desert Road while the eruption was happening and said the noise was like a train.

“There was a big flash,” he said.

“I thought it was lightning and then it started raining sand. It was pretty thick. I heard it rumbling like a train.”

Coker said that when he drove through the Desert Road he could not see the white lines on the road.

“I could just see the yellow glare on the mountain. I only had visibility of about 10 to 15 feet in front of me. It was a bit scary.

“It’s something I’ll probably never see again in my lifetime.”

He said the sand-like ash had covered his truck, and the sign writing on the trailer was barely visible.

Local resident David Bennett who lives on the southern shores of Lake Rotoaira, about 6km away from the eruption, said he heard and saw the mountain erupt just before midnight last night.

He considered himself fortunate no rocks landed on his house last night.

“There were rocks being thrown out. It was like thunder and lightning and fireworks,” Bennett said.

But a major risk to the region is the Okataina Volcanic Centre…cfm?vnum=0401-05= which is considered to be an imminent danger zone. Scientists are said to be “super holding their breath on that one.”

The  Okataina Volcanic Centre lies east of Rotorua. The dome volcano Tarawera is one of a number of dome volcanoes in the centre. The time between eruptions in the Okataina Volcanic Centre is 700- 3000 years but eruptions are 100 to 10,000 times larger than those of cone volcanoes.

“Tarawera is the site of New Zealand’s largest eruption during the last 500 years. Eruptions which created Mt Tarawera began about 18,000 years ago. The volcano is 1111m high and it has three dome shaped peaks with a central fissure. It is surrounded by a number of lakes created or altered by the 1886 eruption.

On 10 June 1886, the Tarawera eruption began at 1.30am and lasted about 5 hours. Witnesses described earthquakes, lightning storms and fireballs, strong winds, suffocating gases, ash fall and darkness during daylight hours as the ash cloud passed overhead.

A 17 km long rift was blasted across the top of the mountain, through Lake Rotomahana and into the Waimangu Valley area. A mixture of steam and finely fragmented rock known as the ‘Rotomahana Mud’ spread over a wide area and was heavy enough to collapse nearby buildings. The world famous Pink and White Terraces were destroyed, and more than 100 people were killed in villages near the mountain. The ‘Buried Village’ of Te Wairoa has been excavated from the rocks, ash and mud which buried it in 1886.” source

GNS science is monitoring the Okataina Caldera with 8 seismographs, 7 continuous GPS stations, lake monitoring and levelling.


According to updates posted by people on TradeME, there is a strong smell of sulphur in Napier. Residents of Taradale have also reported a sulphurous smell and black deposits on cars. Whakatane has experienced ash falls as has Gisborne and Hastings.

Fluorine contaminated ash near Lake Rotowaira

The volcanic earthquake sequence

Tongariro volcanic earthquake sequence

Our other blogs you may be interested in:

Mount Tongariro Gases Above Normal

Mount Tongariro About To Blow?

and these related blogs:

“Mass Aircraft Grounding Possible In NZ Too” Scientists Say 24 April 2010

North Island Eruption Threat “Real” Warns Expert 7 November 2010

Mount Ruapehu Heating Up, Aviation Code Raised To Yellow, Ash Eruption Danger 5 April 2011

2 thoughts on “Mount Tongariro Erupts, Ash Cloud Heading East – updated

  1. More than 2mm of ash can pose a significant risk to livestock grazing on pasture.

    Latest mitigation advice to farmers in the event of future ashfall is as follows:

    1. If ashfall exceeds 2 mm or coats >50 percent of pasture/feed crops, either move stock to less affected areas of the farm or supply supplementary feed

    2. In these situations refill stock drinking troughs from bore or river supplies.

    3. If ash has not washed off pastures after 2-3 days, raise the quantity of supplementary feed and monitor stock condition closely

    4. In general, to reduce impacts from ashfall, maintain pasture length by regular rotation rather than close cropping. Longer pastures are less likely to be completely covered.

    For rural residents with roof-fed tank water supplies:

    1. Temporarily remove downpipe connections to water tanks during and following ashfall to protect stored water

    2. If possible, wait until rainfall clears ash from roofs before reconnecting intake

    3. Water affected by ash will appear turbid (cloudy) and may have a bitter taste. If this is the case, avoid drinking this water and seek alternative supplies.

  2. If the ash winds up on leaves or hay, it will get eaten by cows.
    What about the water supply and milk? Nobody seems to be mentioning anything about how the purity of these essentials are going to be maintained – or how the steps that are in place will be checked for efficacy.
    Food/water security is vitally important when a large environmental disaster threatens contamination.

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