Follow the November 2012 eruption - here
6.10pm: MetService is predicting rain and showers for the central and lower North Island over the next few days. This should help to dissipate ash from last night's eruption.
Katie Milne, Federated Farmers Adverse Events spokesperson says last night's eruption seems to have had minimal impact on farm pasture and stock drinking water.
5.30pm: Dr Nic Peet says that the Tongariro Alpine Crossing, the Tongariro Northern Circuit and the huts on the mountain will remain closed until the risk to public safety has eased.
He says the wider Tongariro National Park remains open with Mount Ruapehu and the Whakapapa and Turoa skifields unaffected by the event.
Peet says DOC will continue to liaise closely with GNS, local councils and iwi about the situation over coming days.
4.20pm: At the briefing Dr Brad Scott from GNS Science said that "there was some further seismicity at 10.30am this morning, but there was no visual observation that could either confirm or deny this."
"Ash samples are being collected, which may give us a heads up in the next 24 hours if there is any fresh magma present," he said.
Scott also said that three new vents "which were not particularly large", also seem to have appeared on the mountain.
4.00pm: Taupo police hold a briefing regarding the eruption.
At the briefing, DOC Area Manager Ruapehu Dr Nic Peet said the search and rescue effort has now been completed and three of the huts - Ketetahi, Waihohonu, Oturere - were clear of trampers.
Three men found at the Mangatepopo Hut on the opposite side of the mountain were safely walked out of the area.
All police teams are now off the mountain.
Peet said that the Ketetahi hut, located high on the slopes of the mountain has suffered significant boulder damage as a result of the eruption.
The Ketetahi hut has "holes through its roof, bunks and floor."
3.22pm: Air New Zealand advises that services are recommencing to Gisborne, Rotorua, Taupo, and Palmerston North.
Flights to and from Napier are still affected and are subject to delays and cancellations as a result of the eruption.
Air New Zealand General Manager Airline Operations and Safety, Captain David Morgan says the airline is working with, "the relevant authorities to safely make adjustments to flight routes to ensure aircraft remain clear of any ash and keep providing a safe service to the travelling public."
2.30pm: Bay of Plenty's civil defence group said a national advisory from the Ministry of Civil Defence about Tongariro's volcanic activity has been cancelled.
The latest assessment from GNS Science is that eruption activity has subsided.
There is no ash being produced from the volcano presently.
2.09pm: Pip James tweeted: Walked outside for the first time today and I can taste the ash from #Tongariro on my lips.. Gross!
1.53pm: The marketing manager of Lake Taupo said the district is still open for business as usual.
Though the Tongariro Alpine Crossing is closed, tracks around Whakapapa and Mt Ruapehu are still open and unaffected.
The Department of Conservation is expected to make a decision on re-opening the Tongariro Alpine Crossing within 72 hours.
1.45pm: A Turangi resident who watched the eruption from her backyard took footage of Tongariro on an iPhone. She said her dogs barked for hours before the event, and she caught about 30 minutes worth of footage.
1.18pm: The New Zealand Army, though situated at the base of Mt Ruapehu and Mt Tongariro, is still training.
The NZ Army says the Waiouru military training area has not been affected by last night's eruption.
12.55pm: GNS has released a map of the predicted ashfall area. To check the map, click here
12.53pm: Volcanologist Michael Rosenberg says observations of Tongariro show eruption activity has subsided.
Rosenberg says it is too early to predict the next series of events, but heightened activity is expected for the next few weeks.
"There are likely to be specific signals of future magma movement beneath the volcano and we continue to monitor the situation through the GeoNet volcano-seismic network of instruments," he says.
Tongariro, like any volcano, could erupt at any time with little or no warning, he says.
11.24am: ONE News has aerial shots of the area surrounding Mount Tongariro.
11.09am: The Ministry of Civil Defence and Emergency Management says it is still monitoring the ash spread. The ministry advises people in the area to:
1. If possible, stay indoors: volcanic ash is a health hazard, especially if you suffer from breathing difficulty. If outside, seek shelter (e.g. in a car or building)
2. When indoors, close all windows and doors to limit the entry of volcanic ash.
3. If caught in volcanic ash falls: Wear a dust mask or use a handkerchief or cloth over your nose and mouth; protect your eyes by wearing goggles. Wear eyeglasses, NOT contact lenses as fine ash will get under the lens.
4. Listen to the radio for updated emergency information and instructions. Follow any evacuation orders issued by authorities. Refer to the back page of the Yellow Pages for evacuation advice.
5. Do not tie up phone lines with non-emergency calls.
6. Stay out of designated restricted zones. Effects of a volcanic eruption can be experienced many miles from a volcano.
10.40am: ONE News reporter Ruth Wynn-Williams tweeted :
"Ash covers everything here on this stretch of road... Feels a little bit lunar (not that I have anything 2base that on)"
10.29am: Scott said if there were to be a magmatic eruption from Tongariro there would be more warning.
10.25am: Brad Scott from GNS said he would "really like to be able to tell us what's going to happen next", but all indicators point to the volcanic activity calming down.
Scott said there were no escalations of volcanic activity before the erruption to signal it was going to happen.
He said there was an unrest episode for several weeks, but eruptions like Tongariro's last night could happen at any time.
10.20am: The Department of Conservation's Dr Nick Peet said its primary function is to support the Police in keeping the public safe.
The department will be looking over the next 24-36 hours to reopen huts on the mountain, which are closed at Tongariro.
Ski fields surrounding Tongariro are still open for business.
10.17am: The press conference kicks off, chaired by Brent Crowe from the Bay of Plenty Police.
He urges people in the area to check their water supplies to check they are not contaminated.
9.57am: Farms have seemingly come out of the eruption unscathed, according to initial reports from Federated Farmers.
According to spokesperson David Broome, the eruption has minimally affected farm pasture and stock drinking water.
"Four farms have been contacted in different geographical parts of the Hawke's Bay and they are yet to report ash," he said.
9.52am: ONE News Facebook users are contributing their experiences with the ash this morning.
Karla Jurczakowski commented: I smelt the sulphur early this morning and now the sun has revealed the ash coating on my vehicle... and that's in Napier so must be a bit of it around...
9.42am: Another update from Air New Zealand, saying a number of domestic flights have been disrupted this morning.
Flights arriving from Auckland Airport to all other domestic and international destinations are going ahead as scheduled.
As at 8.50am, 13 domestic arrivals were delayed and 10 cancelled.
For departures, nine were delayed and 10 were cancelled.
9.30am: Wanganui's civil defence crew is also monitoring the situation. The group said there is no immediate concern for Wanganui, as ash is moving east from the central plateau.
Wanganui Civil Defence and Emergency Management said schools have been told "at this stage there are no safety concerns about children being outside".
9.06am: Julie Nicholson commented on the ONE News Facebook page:
"Not a lot to show you as mist is covering Mt. Pihanga. A helicopter has gone up to check out the eruption.
Just before midnight there was what sounded like a long clap of thunder. The dogs went berserk barking in this area. There was a plume of smoke going eastward after midnight. Then it was all quiet again."
Jan Abbot sent in this picture from Ohakune.
8.50am: The New Zealand Police have advised State Highway 46 is open again.
8.30am: GNS Science has issued a Volcanic Alert Bulletin which retains the volcanic alert level as Level 2 but increases the Aviation Colour Code from Orange to Red.
8.25am:Bay of Plenty Civil Defence Emergency Management Group is on standby and continuing to monitor volcanic activity in the region.
The group has been in contact with the Waikato civil defence groups, and it has offered its support if required.
GNS Science's webcam image of the eruption happening at midnight:
7.55am: State Highway 1 has been re-opened.
7.41am: Air New Zealand says flights to the east of Mount Tongariro, including Gisborne, Rotorua, Taupo, Napier and Palmerston North, may be delayed.
The airline says it is working closely with the Civil Aviation Authority and the MetService to keep up to date with ash movements.
Passengers are advised to check the Air New Zealand website for flight arrivals and departures information which will be updated throughout the day.
7.38am:Peter Lechener from the Civil Aviation Authority told TV ONE's Breakfast the ash cloud extends from the volcano, to Gisborne and Hawke's Bay.
"It stretches up to about 20,000 feet high and it's moving eastward," he said.
Lechner said there is a volcanic hazard zone warning over Tongariro, and planes cannot fly within an 8 mile ring of it.
7.10am: Road closures will be re-assessed once daylight reveals the extent of the ash cloud and other related safety risks have been assessed.
7.00am: Flights have been delayed across the country, while police are warning motorists to avoid travel in the Central Plateau, after the eruption of Mount Tongariro overnight. For the latest information click here.
6.30am: Police are warning motorists in the Central Plateau region to avoid the region.
The situation so far:
News came in around 11.50pm that Mount Tongariro had erupted.
Around five centimetres of ash has fallen on State Highway 46 around the mountain. The road has been closed because of poor visibility, as has the Desert Road section of SH1.