When Volcanoes Attack… White Island Edition

Guest commentary by David Middleton

Aerial photo of White Island after the eruption (CNN).

I’m sure many WUWT readers have seen the headlines and videos.

All volcanoes are dangerous

I would normally follow up “Volcanoes are dangerous” with “No schist Sherlock”… Then again, I’ve seen idiot tourists crossing safety barriers at Grand Canyon NP and eating a picnic lunch in the forest at Grand Tetons NP – right under a sign that said, “No Open Food Containers. Bears Present”. There’s a reason the park gift shop sells fire extinguisher-sized pepper spray dispensers.

No active volcano is safe. Neither are dormant volcanoes. White Island was exceptionally unsafe.

I ran across this article some time ago, when researching a possible post on volcanoes:

ERIK KLEMETTI
SCIENCE
08.06.12
How Dangerous is Visiting New Zealand’s White Island?

THERE HAS ALWAYS been a fragile relationship between volcanoes and tourism.

[…]

However, the danger can appear to be low in some places but in reality, you are literally putting your lives in the hands of tour operators when you make the visit.

One of the best examples of this might be White Island in New Zealand. Off the northern coast of the North Island in the Bay of Plenty, White Island is an active volcano that is part of the volcanic arc that stretches from the Kermadec Islands to the north all the way to Ruapehu in the south. Most of the volcanic edifice sits underwater, but the main crater is above water, sitting out like a sentinel in the Bay. Boat tours of White Island occur daily from Whakatane, where tourists can go to the island and actually walk inside the main crater – which, in theory, is nothing more hazardous than taking a stroll through the Norris Geyser Basin at Yellowstone or Bumpass Hell at Lassen. However, unlike those locations, White Island has erupted recently – in fact, between 1998-2001, the volcano produced multiple VEI 2-3 eruptions and is one of the most active in New Zealand.

Does this mean that tours shouldn’t happen? It is a tricky question. I was in New Zealand in 2009 and considered taking the White Island tour. However, the more I thought about it, the more it bothered me that these tours, although offering warning to tourists of the potential dangers, are potentially the perfect cocktail for a Galeras-like tragedy. By making the visits to the White Island crater seem routine, it can lull the tour operators and tourists into a false sense of security, much like what happened with Stanley Williams and the other volcanologists who visited the crater of Galeras in January 1993. In the case of Galeras, the volcanologists were caught off guard by a relatively small explosion in the crater, leading to the deaths of 6 of the science team and 3 tourists. Visiting White Island is almost exactly the same as climbing down into the crater at Galeras, and although GNS Science keeps close tabs on the activity at White Island, the 1993 tragedy at Galeras shows that even seasoned veterans of volcano monitoring can be fooled or volcanoes can erupt with little to no notice (such as what White Island did in 2000) … and unlike the Tongariro Crossing that passes between two active volcanoes, the White Island tours go into the active volcano’s crater.

[…]

For the White Island tours, people are given protective equipment like gas masks and helmets, but if even a small phreatic (steam-driven) explosion were to happen when a group was in the crater, the consequences could be catastrophic. Will it take a half dozen deaths at White Island to change the culture, or is that merely the cost of being adventurous? It is hard to say.

[…]

Wired

Erik Klemetti is a volcanologist and associate professor of geosciences at Denison University. All volcanoes are dangerous, even the dormant ones. Volcanoes like White Island are particularly dangerous. Unlike Yellowstone or Kilauea, there are no safe areas. Yellowstone and Kilauea are intensely monitored. There are areas that are open to tourism and hiking and areas that are not. Back in 2006, we did the crater hike at Kilauea and then, the next day, did the Blue Hawaiian helicopter tour, flying over an active skylight. That was an awe-inspiring sight.

However, White Island is nothing like Yellowstone or Kīlauea.

Why New Zealand’s White Island Erupted Without Warning
Steam volcanic eruptions like this one can only be detected seconds or minutes in advance

By Shane Cronin, The Conversation US on December 9, 2019

The following essay is reprinted with permission fromThe ConversationThe Conversation, an online publication covering the latest research.

[…]

White Island is one of several volcanoes in New Zealand that can produce sudden explosive eruptions at any time. In this case, magma is shallow, and the heat and gases affect surface and ground water to form vigorous hydrothermal systems.

In these, water is trapped in pores of rocks in a super-heated state. Any external process, such as an earthquake, gas input from below, or even a change in the lake water level can tip this delicate balance and release the pressure on the hot and trapped water.

The resulting steam-driven eruption, also called a hydrothermal or phreatic eruption, can happen suddenly and with little to no warning. The expansion of water into steam is supersonic in speed and the liquid can expand to 1,700 times its original volume. This produces catastrophic impacts.

[…]

Monitoring and warning for hydrothermal eruptions is a huge challenge. We don’t normally see these eruptions coming, no matter how much we would like to. Many systems are already “primed” for such events, but the triggers are poorly understood.

[…]

Scientific American

Shane Cronin is a volcanologist and professor of Earth science at the University of Auckland. Phreatic eruptions are extremely dangerous.

Phreatic eruptions are steam-driven explosions that occur when water beneath the ground or on the surface is heated by magmlava, hot rocks, or new volcanic deposits (for example, tephra and pyroclastic-flow deposits). The intense heat of such material (as high as 1,170 ° C for basaltic lava) may cause water to boil and flash to steam, thereby generating an explosion of steam, water, ash, blocks, and bombs.

USGS

According to Brown et al., 2017, there have been at least 278,368 fatalities related to volcanic activity since 1500 AD. As expected, the vast majority (99.7%) of these deaths were among people living in the vicinity of volcanoes. The next largest group was tourism-related.

Table 6 from Brown et al., 2017

Group Incidents Number of fatalities
Tourists or tourism-related 113 561
Scientists 22 67
Miners 6 108
Media 6 30
Emergency response personnel 5 57

Tourism-related fatalities

Many of these deaths resulted from complacency and/or ignoring safety protocols.

Persistent volcanic activity can result in hazard footprints that rarely extend beyond the crater. Such regular activity can engender complacency in tourists and guides, although small changes in activity, topography or wind direction can change the hazard footprint. At least 22 eruptive (and 5 indirect) fatal incidents occurred more than 1 year after the eruption start date, commonly at volcanoes known for regular activity. Long-lived eruptions affect analysis of relationships with VEI, as the VEI in GVP (2013) normally represents the tephra volume over the full length of the eruption. Ninety-one of the 113 incidents (81%) occurred during quiescence or low-explosivity eruptions of VEI 0–2.

[…]

Tourist co-operation is a requirement for safety in any volcanic setting, with visitors being relied upon to heed warnings and exercise appropriate caution. The 23 fatalities at Yellowstone occurred between 1890 (Whittlesey, 1995) and 2016 (Mettler, 2016), where deaths resulted from immersion in the near boiling water of thermal pools. Whittlesey (1995) describes these as accidental falls and misadventure – where the victims believed the pools swimmable. Of these fatalities, nine (36%) were children younger than 10 years old. Educational and safety information is provided and safe boardwalks through thermal areas have been installed, yet injuries are still frequent as visitors choose to engage in risky behaviour (Lalasz, 2013). Despite the frequency of injuries, only two fatalities are recorded in the last 30 years at Yellowstone, suggesting safety measures have been largely successful and the visitor population has become more risk averse at this volcano. Seventeen deaths are recorded at Rotorua, New Zealand since 1946, of which at least seven were tourists. These fatalities occurred primarily at hot pools through quiescent gas emissions. The decrease in incidents over time seen at Yellowstone is not seen here, with seven incidents since 2000. Recommendations were made in 2010 aimed at improving safety at geothermal pools (Bassindale and Hosking, 2011).

Brown et al., 2017

Tourism should have never been allowed on White Island.

Science-related fatalities

Professional geologists know they are risking their lives when they study volcanoes up close – But that’s their job, their chosen profession. And sometimes they pay the ultimate price for trying to increase our knowledge of how volcanoes work. Erik Klemetti mentioned the 1993 Galeras incident, in which 9 members of a 16 person expedition were killed.

USGS volcanologist David Johnston was killed in the 1980 eruption of Mount St. Helens.

David Johnston, a 30-year-old volcanologist with the U.S. Geological Survey, was swept away by the catastrophic eruption of Mount St. Helens on the morning of May 18, 1980. As one of the first members of the U.S. Geological Survey monitoring team to arrive at Mount St. Helens, and the scientist in charge of volcanic-gas studies, Dave spent long hours working on and close to the mountain. Ironically, he was caught at an observation post that was considered relatively safe. From his experience with active Alaskan volcanoes, Dave understood better than most the hazards of explosive volcanism. At the same time, he repeatedly voiced the conviction that adequate hazard evaluations require accepting the dangers of on-site monitoring of active volcanic processes. The volcano-monitoring effort of which Dave was part helped persuade the authorities first to limit access to the area around the volcano, and then to resist heavy pressure to reopen it, thereby holding the May 18 death toll to a few tens instead of hundreds or thousands.

USGS

Volcanologists and Katia &Maurice Krafft and Harry Glicken were killed by a pyrocalstic flow from Mount Unzen in 1991…

In June 1991, while filming eruptions at Mount Unzen (Japan), they were caught in a pyroclastic flow, which unexpectedly swept out of the channel that previous smaller flows had been following and onto the ridge they were standing on. They were killed instantly along with 41 other people, including fellow volcanologist Harry Glicken, several firefighters, and journalists also covering the eruptions.

Wikipedia

Brown et al., 2017 found that 67 deaths were related to scientific activities in and around active volcanoes. Almost half of these deaths occurred in the 1952 destruction of the Japanese oceanographic research vessel Kaiyo Maru No. 5 while observing a massive eruption of Myōjin-shō in the Bayonnaise Rocks region of a large submarine caldera.

Volcanoes are dangerous… Even to people who understand the risks.

Politician-related fatalities

Whakaari/White Island: Police and WorkSafe launch investigations
Thomas Manch and Henry Cooke
Dec 10 2019

[…]

The dead include tourists and tour guides, who were among 47 people on the island to view the volcano crater that afternoon. 

A spokeswoman for WorkSafe said the investigation would focus on the harm and the loss of life.

WorkSafe New Zealand has opened a health and safety investigation into the harm and loss of life caused by the White Island eruption.

“As the workplace health and safety regulator and administrator of the Adventure Activities Regulations, WorkSafe will be investigating and considering all of the relevant work health and safety issues surrounding this tragic event.”

A day after the eruption, politicians are facing questions on why tours of the volcanic island — which had in recent weeks appeared closer to eruption — were allowed. 

Prime Minister Jacinda Ardern said “bigger questions” would be asked and answered about the death of multiple tourists on Whakaari/White Island. 

The prime minister, along with Tourism Minister Kelvin Davis and Local Government Minister Nanaia Mahuta, were unwilling to comment on the matter on Tuesday afternoon.

[…]

Stuff…

The only people who should be answering questions are the politicians who allowed this to happen. The geology of White Island was not a mystery or a secret.

Geology of White Island

Whakaari/White Island “is an active composite stratovolcano in the Bay of Plenty, New Zealand, that comprises many small volume (<0·1 km3) andesite–dacite lava flows and pyroclastic deposits with phenocryst contents of ∼15–44%”.  It is located in the Taupo Volcanic Zone (TVZ). This is the youngest and most active part of the 22 million year old (22 ma) Cenozoic continental margin arc volcanic system of North Island, New Zealand. It’s actually two over-lapping composite stratocones, the extinct Ngatoro Cone and very active Central Cone (Cole et al., 2000) .

Figure 1 from Cole et al., 2000. “Map of the Bay of Plenty. Offshore faults and main structural elements are from Wright (1992). VR, Volckner Rocks. Inset map of Taupo Volcanic Zone shows location of White Island and other andesitic volcanoes mentioned in the text. Thick dashed line in inset map represents the southern limit of inferred en-echelon cross-fracture structures (Wright, 1992).

“Safe” is an antonym to White Island.

White Island is New Zealand’s most active volcano and in historical times (the last 150 years) has been characterized by sporadic eruptive episodes featuring small phreatic, phreatomagmatic and strombolian eruptions, associated with extensive fumarolic activity. The last eruptive episode on White Island began in 1976, with numerous small phreatomagmatic and strombolian eruptions (Houghton & Nairn, 1989). Olivine-bearing basaltic andesite bombs and blocks were erupted in March 1977 (Cole & Graham, 1987), and it is these samples that are compared and contrasted with the prehistoric lavas exposed in outcrops on Ngatoro and Central cones. The most recent eruptive episode ceased in 1992, although small phreatic explosions continue, and the level of activity is now (1999) again increasing.

Cole et al., 2000

When it comes to volcanoes, these are really bad words:

  1. Phreatic
  2. Phreatomagmatic
  3. Strombolian
  4. Olivine-bearing basaltic andesite bombs and blocks

Under most conditions, Strombolian eruptions are relatively safe to watch; but there’s no safe place on White Island from which to view one.

References

Brown, S.K., Jenkins, S.F., Sparks, R.S.J. et al. “Volcanic fatalities database: analysis of volcanic threat with distance and victim classification”. J Appl. Volcanol.6, 15 (2017) doi:10.1186/s13617-017-0067-4

Cole, J. Wh., T. Thordarson, R. M. Burt. “Magma Origin and Evolution of White Island (Whakaari) Volcano, Bay of Plenty, New Zealand”. Journal of Petrology, Volume 41, Issue 6, June 2000, Pages 867–895, https://doi.org/10.1093/petrology/41.6.867

Featured Image

Phreatic eruptionPhreatic eruption
“Phreatic eruption at the summit of Mount St. Helens, Washington. Hundreds of these steam-driven explosive eruptions occurred as magma steadily rose into the cone and boiled groundwater.” (USGS)

via Watts Up With That?

https://ift.tt/2sguEgm

December 11, 2019 at 05:00AM

2 thoughts on “When Volcanoes Attack… White Island Edition”

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