White Island eruption

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#2371780 10-Dec-2019 13:56

empacher48:

tdgeek:

Ok, cancel alerts, waste of time, there is no need.

That is a bit extreme, don’t you think? We are dealing with Mother Nature, to whom is rather unpredictable, no matter what we think.

The alert levels do provide a need, but still have a level of uncertainty. The people who monitor the codes are aware of this and do not use the code exclusively when weighing up the risk to operate. If it were, the ski fields on Ruapehu would’ve closed down years ago.

Based on you comments, not extreme. They aren't used. The increased activity at WI in the last 2 weeks was significant. Its towards the end of the eruption cycle. Unused. As you say, its a risk. No need for alerts off they stay at GNS and are not used by those talking passengers to an active crater.

How often is Ruapehu at alert 2? When it is, for how long? When it was, a Google search example May 2016 example, DoC cut off the summit to climbers and trampers.

Many recent signs at WI, been a while since its last eruption cycle, nothing. Well, for some reason its ONLY up to tour operators to go to the crater

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#2371784 10-Dec-2019 14:01

Fred99:

Both White Island and Ruapehu have phreatic eruptions, superheated pressurised steam driven. So while the heat source is still magma (at say a thousand degrees) at depth, lower temperatures above 100 at higher level in non-molten rock create high pressures if confined by the rock and mud etc and it's impossible to predict when it'll let rip - like a pressure cooker full of mud, but you've got no idea what the pressure actually is, and no real idea of how strong the lid is. So they can let rip at any time with very little - or no warning.

One of the regular monitoring methods is sampling crater lake temps and chemical composition and measuring gasses.

The geonet site has alert bulletins - you can look back at years of past alerts. If they closed Ruapehu every time the crater lake warmed or there was a slight uptick in seismic activity etc, that would be the end of skiing in the NI.

More concern is the big volcanoes (ie Taupo) or monogenetic field in Auckland. It's nice to believe that there'd be warning, but as neither have ever been observed, there's only theory and observation of similar (but not the same) events elsewhere to go on. Tarawera was a biggie, there was some warning (quakes) but no instrumental or chemical monitoring back then.

How do you define a light uptick? The last few weeks alerts for WI are they slight? Bear in mind that you are skiing on a mountain or taking a selfie at the crater edge, walking in the crater.

I read somewhere years ago that underneath Taupo is not disimilar in construction to Yellowstone caldera? I.e. a smaller super volcano potentially.

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#2371791 10-Dec-2019 14:04

Fred99:

Both White Island and Ruapehu have phreatic eruptions, superheated pressurised steam driven. So while the heat source is still magma (at say a thousand degrees) at depth, lower temperatures above 100 at higher level in non-molten rock create high pressures if confined by the rock and mud etc and it's impossible to predict when it'll let rip - like a pressure cooker full of mud, but you've got no idea what the pressure actually is, and no real idea of how strong the lid is. So they can let rip at any time with very little - or no warning.

One of the regular monitoring methods is sampling crater lake temps and chemical composition and measuring gasses.

The geonet site has alert bulletins - you can look back at years of past alerts. If they closed Ruapehu every time the crater lake warmed or there was a slight uptick in seismic activity etc, that would be the end of skiing in the NI.

More concern is the big volcanoes (ie Taupo) or monogenetic field in Auckland. It's nice to believe that there'd be warning, but as neither have ever been observed, there's only theory and observation of similar (but not the same) events elsewhere to go on. Tarawera was a biggie, there was some warning (quakes) but no instrumental or chemical monitoring back then.

I recall when Ruapehu erupted in the mid 90's there was increased activity beforehand, so that was a warning to people to stay off it. I think it would be common sense that when there is more than normal activity, volcanoes should be avoided. I wouldn't feel comfortable going up Ruapehu if I knew it was experiencing more than normal activity. There was a major loss of life previously with that train disaster when it erupted last century. Luckily we have better monitoring now, but there is no point in the monitoring if it isn't used to inform people that the risk is higher than normal. But the question is, should it be down to the persons choice, or should be be regulated. Taupo has been dormant for centuries, so no sure how much of a risk it is in our lifetimes. But if it erupts, I think it will affect the whole country, and it probably isn't something that is worth worrying about.

GV27

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#2371792 10-Dec-2019 14:05

Fred99:

More concern is the big volcanoes (ie Taupo) or monogenetic field in Auckland. It's nice to believe that there'd be warning, but as neither have ever been observed, there's only theory and observation of similar (but not the same) events elsewhere to go on. Tarawera was a biggie, there was some warning (quakes) but no instrumental or chemical monitoring back then.

Auckland is more at risk from fallout from other places than the Auckand volcanic field. Wind direction matters.

The nexus of likely to happen vs. likely to cause damage makes Taranaki our biggest headache.

tdgeek

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#2371794 10-Dec-2019 14:09

mattwnz:

Fred99:

Both White Island and Ruapehu have phreatic eruptions, superheated pressurised steam driven. So while the heat source is still magma (at say a thousand degrees) at depth, lower temperatures above 100 at higher level in non-molten rock create high pressures if confined by the rock and mud etc and it's impossible to predict when it'll let rip - like a pressure cooker full of mud, but you've got no idea what the pressure actually is, and no real idea of how strong the lid is. So they can let rip at any time with very little - or no warning.

One of the regular monitoring methods is sampling crater lake temps and chemical composition and measuring gasses.

The geonet site has alert bulletins - you can look back at years of past alerts. If they closed Ruapehu every time the crater lake warmed or there was a slight uptick in seismic activity etc, that would be the end of skiing in the NI.

More concern is the big volcanoes (ie Taupo) or monogenetic field in Auckland. It's nice to believe that there'd be warning, but as neither have ever been observed, there's only theory and observation of similar (but not the same) events elsewhere to go on. Tarawera was a biggie, there was some warning (quakes) but no instrumental or chemical monitoring back then.

I recall when Ruapehu erupted in the mid 90's there was increased activity beforehand, so that was a warning to people to stay off it. I think it would be common sense that when there is more than normal activity, volcanoes should be avoided. I wouldn't feel comfortable going up Ruapehu if I knew it was experiencing more than normal activity. There was a major loss of life previously with that train disaster when it erupted last century. Luckily we have better monitoring now, but there is no point in the monitoring if it isn't used to inform people that the risk is higher than normal. But the question is, should it be down to the persons choice, or should be be regulated. Taupo has been dormant for centuries, so no sure how much of a risk it is in our lifetimes. But if it erupts, I think it will affect the whole country, and it probably isn't something that is worth worrying about.

I agree. From a post above, there seemed to be little advice offered to the passengers. Thats being the case the alerts are meaningless. Its about the risk, and if you are "in" the volcano, instead of on a skifield, wellaway from the crater, the risks are quite different. As would the alerts be. Except WI has no alert system to decree, go-nogo

Common sense? The tour guy said she is fine, dont worry, eftpos or credit card sir??

Fred99

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#2371797 10-Dec-2019 14:14

tdgeek:

This quote makes it foreseeable. The issue is water. If its a dry volcano, lava tends to flow, and you get more consistent activity changes, such as St Helens, but magma and water dont mix, that's explosion eruptions.

St Helens was a phreatic event. There was warning, but not of the scale of what was to happen.

empacher48

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#2371798 10-Dec-2019 14:14

tdgeek:

Based on you comments, not extreme. They aren't used. The increased activity at WI in the last 2 weeks was significant. Its towards the end of the eruption cycle. Unused. As you say, its a risk. No need for alerts off they stay at GNS and are not used by those talking passengers to an active crater.

How often is Ruapehu at alert 2? When it is, for how long? When it was, a Google search example May 2016 example, DoC cut off the summit to climbers and trampers.

Many recent signs at WI, been a while since its last eruption cycle, nothing. Well, for some reason its ONLY up to tour operators to go to the crater

I never said they were never used.

But I did say that anything can happen in our volcanoes, no matter what the alert level is. Just like Earthquakes happen, no matter what we think.

Yes it is up to the tour operators to go the crater of White Island, just as it is up to the managers of the ski fields to operate on Ruapehu.

They are all trying to make money while managing the risk of an eruption.

As you said, the 2016 Event started on the 11 May and lasted until 5th July(source: GNS weekly alert bulletins), the ski season started on the mountain on the 30th June (2016 Annual Reports), two weeks late due to a lack of snow and were operating while Ruapheu was at alert level 2.

During that event the lake temperature increased to maximum of 54 degrees and was an increase in the volcanic tremor. It was also the last time the aviation code changed from green to yellow, so we had to slightly change our routing across the North Island.

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#2371800 10-Dec-2019 14:15

In an example of really unfortunate coincidence, yesterday's The Detail podcast (an RNZ/Newsroom production) was on the risk to NZ from its volcanoes.

I listened to it yesterday morning, and so had been thinking of one of the points made in the podcast - that the volcanoes we should be most concerned about were the 'cone-shaped' ones, namely Taranaki, Ruapehu, Tongariro and White Island.

Worth a listen for some context - https://www.rnz.co.nz/programmes/the-detail/story/2018715016/when-aotearoa-heats-up-from-below

Fred99

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#2371802 10-Dec-2019 14:16

GV27:

Fred99:

More concern is the big volcanoes (ie Taupo) or monogenetic field in Auckland. It's nice to believe that there'd be warning, but as neither have ever been observed, there's only theory and observation of similar (but not the same) events elsewhere to go on. Tarawera was a biggie, there was some warning (quakes) but no instrumental or chemical monitoring back then.

Auckland is more at risk from fallout from other places than the Auckand volcanic field. Wind direction matters.

The nexus of likely to happen vs. likely to cause damage makes Taranaki our biggest headache.

Could be. It gets ignored because it's been very quiet since white folks arrived.

tdgeek

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#2371803 10-Dec-2019 14:17

Fred99:

tdgeek:

This quote makes it foreseeable. The issue is water. If its a dry volcano, lava tends to flow, and you get more consistent activity changes, such as St Helens, but magma and water dont mix, that's explosion eruptions.

St Helens was a phreatic event. There was warning, but not of the scale of what was to happen.

True. The expansion they measured was substantial, but who knows what it would do

tdgeek

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#2371811 10-Dec-2019 14:23

empacher48:

tdgeek:

Based on you comments, not extreme. They aren't used. The increased activity at WI in the last 2 weeks was significant. Its towards the end of the eruption cycle. Unused. As you say, its a risk. No need for alerts off they stay at GNS and are not used by those talking passengers to an active crater.

How often is Ruapehu at alert 2? When it is, for how long? When it was, a Google search example May 2016 example, DoC cut off the summit to climbers and trampers.

Many recent signs at WI, been a while since its last eruption cycle, nothing. Well, for some reason its ONLY up to tour operators to go to the crater

I never said they were never used.

But I did say that anything can happen in our volcanoes, no matter what the alert level is. Just like Earthquakes happen, no matter what we think.

Yes it is up to the tour operators to go the crater of White Island, just as it is up to the managers of the ski fields to operate on Ruapehu.

They are all trying to make money while managing the risk of an eruption.

As you said, the 2016 Event started on the 11 May and lasted until 5th July(source: GNS weekly alert bulletins), the ski season started on the mountain on the 30th June (2016 Annual Reports), two weeks late due to a lack of snow and were operating while Ruapheu was at alert level 2.

During that event the lake temperature increased to maximum of 54 degrees and was an increase in the volcanic tremor. It was also the last time the aviation code changed from green to yellow, so we had to slightly change our routing across the North Island.

I said they are not used. Tour operators make the call, no one else. As I stated, one example where DoC shut down the Ruapehu summit, so they are used to protect the public. Not WI though.

How does Ruapehu crater location to the skifields compare to walking IN the WI crater? Thats not apples with apples. Ruapeha has many minor eruptions, mush less frequent major eruptions, but in the case of WI, an average eruption is a major problem if you are there. You can run fast but you are IN the crater. Very different. Location and risk wise, WI has a major eruption every few short years.

GV27

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#2371829 10-Dec-2019 14:28

Fred99:

Could be. It gets ignored because it's been very quiet since white folks arrived.

We've got a pretty good handle on when the last really big eruption was. Minor eruptive activity/unrest is harder to understand.

Conventional wisdom used to say you had many years of warning as Taranaki would take a while to build up the kind of pressure needed for a large scale eruption but now it seems they model for different kinds of eruptions with rapid onsets as a possibility. But a big Taranaki eruption would make Ruapehu's recent activity look minuscule by comparison.

MikeB4

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#2371831 10-Dec-2019 14:30

tdgeek:

I said they are not used. Tour operators make the call, no one else. As I stated, one example where DoC shut down the Ruapehu summit, so they are used to protect the public. Not WI though.

How does Ruapehu crater location to the skifields compare to walking IN the WI crater? Thats not apples with apples. Ruapeha has many minor eruptions, mush less frequent major eruptions, but in the case of WI, an average eruption is a major problem if you are there. You can run fast but you are IN the crater. Very different. Location and risk wise, WI has a major eruption every few short years.

Ruapehu is part of a National park and comes under DOC. Whakaari/White Island is privately owned.

tdgeek

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#2371832 10-Dec-2019 14:35

MikeB4:

tdgeek:

I said they are not used. Tour operators make the call, no one else. As I stated, one example where DoC shut down the Ruapehu summit, so they are used to protect the public. Not WI though.

How does Ruapehu crater location to the skifields compare to walking IN the WI crater? Thats not apples with apples. Ruapeha has many minor eruptions, mush less frequent major eruptions, but in the case of WI, an average eruption is a major problem if you are there. You can run fast but you are IN the crater. Very different. Location and risk wise, WI has a major eruption every few short years.

Ruapehu is part of a National park and comes under DOC. Whakaari/White Island is privately owned.

Thanks Mike, wasn't aware WI was private property.

PM and Paula Bennett seem to agree that something has to change here

GV27

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#2371839 10-Dec-2019 14:54

https://www.stuff.co.nz/business/industries/118071975/whakaariwhite-island-owner-the-buttle-family-declines-to-comment-after-deadly-eruption

White Island Tours chairman Paul Quinn told TVNZ on Tuesday morning two of its staff were unaccounted for following the eruption.

"We take our health and safety responsibilities very seriously and this is a big tragedy unfortunately for us," Quinn said.

In 2018 it took 17,500 visitors to the island, he said.

It received reports from New Zealand Crown Research Institute GNS on what volcanic activity levels were on the island, he said.

It was deemed safe for tours to operate if it was at "level two" or below, as it was yesterday, subject to weather, he said.

"We take our steer from GNS on that."

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