Hours after a magnitude 4.7 earthquake near Opotiki rocked the Bay of Plenty, it has been revealed that magma is bubbling high within the Mount Tongariro volcano.
Tests have revealed that magma is bubbling high inside Mount Tongariro, which could suggest a larger eruption is imminent.
A series of samples have been tested since the volcano’s Te Mari crater erupted on Monday night, but the latest results give the greatest insight.
The results detected sulphur dioxide and carbon dioxide in the steam plume, which indicated that magma was near the surface of the crater, GNS Science head of volcanology Gill Jolly told Radio New Zealand.
This could lead to a magmatic eruption, but it’s also likely that a series of steam eruptions could follow, Jolly said. Or perhaps, nothing at all.
The volcano was still ejecting steam and gas this morning, GNS vulcanologist Michael Rosenberg said.
Tremors continue to shake the earth below it, he said. more here
It has also been confirmed that White Island, a volcano off the Bay of Plenty, experienced an eruption on Tuesday night and that ash is reaching the mainland.
If a magmatic eruption occurs at Tongariro it could be similar to Mount Ngaruahoe‘s in the 1970s.
In January 1973, Ngauruhoe discharged red-hot blocks of lava, and periodic activity continued throughout the year. In 1974 and 1975 there were explosive eruptions of ash, and blocks of lava were thrown as far as 3 km away. During the last violent eruption, gases streamed from the crater for several hours, producing a churning plume of ash that towered up to 13 km above the crater. This column then collapsed and formed ash and scoria avalanches that swept down the sides of Ngauruhoe, leaving trails of rubble in their wake. source
No word yet as to whether access to the area is to be restricted and as far as we know ski fields in the area are still open. But with advice from GNS ranging from ‘nothing could happen’ to ‘there could be a magmatic eruption’ we’re very surprised that a more precationary approach is not being taken and that the current volcanic activity is being regarded as little more than a scientific curiosity in New Zealand. Indeed there seem to a desire to play down the hazards, which is rather unwise.
“Visitors to White Island are now at the highest level of risk since the end of the 2001 eruptions. Additional hazards to visitors to the island now include the health effects of volcanic ash and acid gas exposure, including respiratory issues, skin and eye sensitivity to acid gases. Explosive eruptions can occur at any time with little or no warning. We advise a high level of caution should be taken, if visiting the island.”
Both volcanoes remain at alert level 2.
Pumice field floating in Pacific Ocean
An massive area of floating pumice 250 nautical miles in length and 30 nautical miles wide was spotted in the South Pacific ocean yesterday by a Royal New Zealand Air Force (RNZAF) Orion. Watch the YouTube VIDEO HERE
Googlemap of the Monowai Seamount
The RNZAF Orion, which was on Maritime patrol from Samoa to New Zealand, relayed the information to HMNZS CANTERBURY and last night, approximately 85 nautical miles West South-West of Raoul Island CANTERBURY spotted the phenomenon.
It is believed that the pumice was ejected from the underwater volcano Monowai, which has been active along the Kermadec Arc.
Auckland could be affected by ash again
Dr Jan Lindsay, Senior Lecturer and vulcanologist at University of Auckland said on Tuesday:
“It will be interesting to see how the (Tongariro) eruption develops – whether it continues for months, or is over already.
Ash from Tongariro has reached Auckland many times over the last 80,000 years.
If the former we may see ash reaching Auckland, depending of course on the wind direction. We know from looking at sediment cores from Auckland lakes that ash from Tongariro has reached Auckland many times over the last 80,000 years. Of course it only needs to be in the atmosphere to cause a problem: we are already seeing flights cancelled and the impact on flights in and out of Auckland airport could be significant.”
Shinmoedake volcano in Japan
“In Jan-Feb 2011, there was an eruption in the Shinmoedake volcano in southern Japan, which is very similar to Tongariro, and it erupts a similar composition of magma. It had a magmatic eruption that was much larger than what we’ve seen today.
We studied its impacts on critical infrastructure, on towns and communities and agriculture. It did cause some disruption. There was centimetres-worth of ash across vast tracts of agricultural land and some towns. There were some direct impacts to agriculture, but after six months, things were mostly back to normal. There were some big issues with towns and roads, and that created coordination and management issues.
There were some disruptions to electricity supplies as well, and surface irrigation water. As far as health concerns, limiting exposure, wearing a mask and avoiding times when ash was blowing around outside was sufficient to mitigate those issues. It’s quite a good example of what might happen if there were a much bigger eruption from Tongariro.”
News report of the Shinmoedake eruption
“Earthquake, tsunami, nuclear plant meltdowns — as if the people of Japan didn’t have enough to cope with, a volcano began erupting Sunday.
Hundreds of people were forced to flee when the Shinmoedake volcano on the southern island of Kyushu began spewing ash and boulders.
The explosion from the eruption could be heard miles away and an ash plume extended two miles into the sky.
Shinmoedake, one of several volcanic peaks in the Kirishima mountain range, is 950 miles from the epicenter of Friday’s earthquake and scientists weren’t sure if the quake triggered the eruption.” source
Volcano – earthquake link
Interestingly there may be a link between the increased activity at Tongariro and White Island and a recent deep earthquake in New Zealand in early July.
A magnitude 7 earthquake occured 60km south of the Taranaki town of Opunake. It was the largest in the area for 120 years and people from Bay of Plenty to Otago reported feeling it.
The quake went largely unreported outside of New Zealand but the Earthquake Commission received almost 1650 claims
To date, there have been 45 claims from New Plymouth, with 34 in South Taranaki and eight in Stratford…
On July 7, EQC spokesman Richard Braddell said most compensation claims received were of low value, almost all of them being contents claims.
He supplied an updated list yesterday which shows that claims have now been received from 50 New Zealand districts and city areas.
By far and away the largest is Christchurch city with 341 claims, followed by Kapiti Coast (124) and Wellington city (114).
Of the lower North Island regions neighbouring Taranaki, there have been 93 claims received from Whanganui.
A claim each was even received from Auckland in the north and Invercargill in the south. ” source
Active volancoes and Recent Earthquakes