Academics referenced seven life-threatening "near misses" at Whakaari in the years leading up to December's devastating eruption.
Research shows academics published mounting evidence of the "severe" risks at Whakaari, before the fatal eruption on December 9 fatally injured 21 people and left at least a dozen others critically unwell, with blast injuries and burns.
Thirty-eight of the 47 people on the erupting island were from the Royal Caribbean cruise Ovation of the Seas and this week, Australian law firm Stacks Goudkamp confirmed it had been hired by passengers and their family members to sue the cruise line.
Research funded by the Earthquake Commission (EQC), published in 2018, cited "seven near misses" since 2006, where rocks and lava (ballistics) thrown from Whakaari had threatened lives.
Principal investigator Dr Ben Kennedy from the University of Canterbury, and his team, wrote about the "increasing vulnerable population exposed to ballistic hazards on volcano summits" as volcano tourism grew globally.
They referred to the deaths of 58 lunching hikers in Japan in 2014 after Mt Ontake erupted.
"Only the bad weather and time of eruption (near midnight) prevented casualties being of a similar scale from the August 2012, Upper Te Maari eruption on the Tongariro Crossing," they wrote.
"Similar eruptions have occurred frequently over the last seven years at Whakaari.
"These unheralded eruptions exemplify the hazard and risks from volcanic ballistics are poorly understood and difficult to manage," Kennedy and his team wrote.
They described the hazards as "severe" and concluded volcano ballistics were "often ignored" in hazard assessments.
A master's thesis completed in 2018 by a member of Kennedy's research team, Stephanie Gates, found that up to 21 per cent of the tourism pathway at Whakaari was pelted with "blocks with sufficient impact energies to cause serious injury or death" in an eruption at 9.35pm on April 27, 2016.
The volcano was at alert level 1 at the time.
GNS staff ruled in the weeks after the eruption that "survivability during the eruption most likely would have been low in areas of the main crater floor".
Gates' research analysed the volcanic material left by the eruption, determining that blocks were ejected "at speeds between 45 and 65 metres per second".
Between 404 and 507 tonnes of "ballistic mass" was ejected, removing 13-15m of sediment from the crater lake floor and shearing off and breaking survey pegs at ground level.
Gates said the footprint was "consistent with small Whakaari eruptions in the past".
"The modelling suggests that even small eruptions at Whakaari pose a potentially lethal hazard."
"Daily tours, weather permitting, take about 18,000 visitors per year within the ballistic hazard footprint of previous eruptions, as well as the pyroclastic flow and ash fall hazard footprints," she wrote.
Pyroclastic flows - as seen at White Island on December 9 - destroy nearly everything in their path with fast-moving, extremely hot gases (normally 200-700C) and rock fragments ranging from ash to boulders.
Gates told NZME this month her thesis was not "quantified analysis of the danger or risk posed to tourists" and it "focused on the eruption dynamics and hazard footprint".
Her thesis said the Whakaari hazard footprint was "poorly constrained" and "the proven potential for harm [from ballistics] highlights the need for greater appreciation of their significance".
However, it also acknowledged "closure of attractions due to an eruption can severely impact individuals and community livelihoods" and that Whakaari was a "unique case" because it was privately owned by the Buttle family.
Whakaari was at alert level 2 leading up to December's eruption, meaning scientists at the Crown Research Institute GNS Science had issued a public advisory about moderate to heightened volcanic unrest.
The alert had been in place for exactly three weeks on December 9.
GNS volcanologist Brad Scott spoke to the Herald on Sunday about New Zealand's volcanic alert level system, and tourism at Whakaari, in 2014 - 100 years since an avalanche of volcanic debris killed at least 10 sulphur miners on the island.
The story said, "GNS Science staff have had 'terse discussions' with tour operators who have landed visitors on the island in conditions which make volcanologists anxious" and "anything between a level 2 and 3 would put Scott off going".
"We don't visit but they still go," Scott was quoted saying.
GNS Science staff had planned to install new monitoring equipment on the island on December 12, 2019.
GNS Science said the trip "would have been subject to a risk assessment at the time", in a written statement to NZME this month.
EQC had planned to capture the event by sending a film crew with the staff but the eruption put a halt to the plans that week.
The commission helps fund volcano monitoring and modelling in New Zealand but it also supports public education.
EQC head of resilience, strategy and research Dr Jo Horrocks told NZME: "I think we are very aware that New Zealand's next natural hazard could be a volcanic eruption that impacts people and property and economy."
The Buttle family decides who can access Whakaari and since the 1990s, most visitors have come with White Island Tours, formerly known as Peejay Tours.
White Island Tours and other operators at Whakaari are responsible for the health and safety of their staff and their tourists and are registered with WorkSafe.
Operators going to or around the island, such as White Island Tours, Kāhu Helicopters and Volcanic Air, each make their own decisions about whether to go or not.
They factor in GNS Science's latest observations about the level of volcanic unrest and their own observations.
GNS Science is expected to distribute information about geological hazards - such as those at Whakaari - to other government agencies, the wider public and the media, under its agreements with the National Emergency Management Agency.
But the list of roles and responsibilities at Whakaari doesn't end there.
Because it is an island 50km offshore, the Minister of Local Government is the territorial authority for the island, not a district council or regional council.
There is no district plan under the Resource Management Act for the island, because "as an active volcano, it is subject to limited use and development", according to documents released to NZME by the current Local Government Minister, Nanaia Mahuta.
The previous Associate Local Government Minister, Jacqui Dean, signed a Memorandum of Understanding with the Bay of Plenty Civil Defence Emergency Management Group in 2017, putting the group in charge of emergency responses at the island.
These are just some of the decision-makers in the Whakaari web.
Academics have been trying to inform the web without deteriorating connections and relationships within it.
One link in the web was between volcanologist Professor Ben Kennedy and White Island Tours staff member Hayden Marshall-Inman, who died in the eruption.
He had personally guided Kennedy and his researcher colleagues at the island dozens of times, when the operators helped facilitate his research.
"I knew and really liked Hayden, and had a lot of respect for him and what he did for his job," Kennedy said.
"We'd have fish and chips in the evening and a beer and he shared lots of videos and personal observations with me. So I've got a real personal, and ... emotional connection to the whole thing."
He said the operators' interest in the university's research had been growing.
"We were actively trying to speed up the uptake of our research into decision-making, such as developing an educational video suitable for tourists which highlighted new research ... We had been discussing [it] via emails and meetings, but it was slow. Not at the fault of anyone - but the situation."
Academics like Kennedy work closely with GNS Science to make sure their expertise is available and being used.
GNS Science has developed its own framework to help determine when the fatality risk is low enough for the institute's staff to do fieldwork at hazardous sites.
Kennedy uses this "very rigorous protocol" to decide when and where he should and shouldn't go.
He said December's eruption may mean tourism operators operating on or around volcanoes in New Zealand end up following GNS' decision-making system, or something similar.
His University of Canterbury colleague Professor Tom Wilson specialises in assessing and calculating disaster risk from natural hazards.
In his opinion, the volcanic risk governance of Whakaari has been "quite complicated, with lots of different pressures and challenges" but over the past couple of years there has been "an active process, trying to untangle this".
"This volcano could potentially erupt at any time, with no useful warning, and so managing risk in such a highly uncertain environment is really difficult."
Wilson also said the uptake of any academic research "can be very, very slow" and "often needs to be translated" for decision-making.
"What becomes essential, though, is who actually has the responsibility and the role to manage risk, and for whom, at the island?"
When NZME asked WorkSafe this question, it said it could not provide the answer while WorkSafe conducted its Whakaari eruption investigation, "as we do not wish to prejudice the investigation".
NZME asked White Island Tours about its relationships with scientists and researchers, and its responses to findings about Whakaari published in 2018 and 2019.
It also told NZME it would be inappropriate to comment on these matters while WorkSafe's investigation and the Coronial Inquiry in New Zealand took place.
White Island Tours also declined to comment on Australian law firm Stacks Goudkamp's legal action against cruise line Royal Caribbean.
The firm confirmed this week it had been hired by Ovation of the Seas passengers and their family members to take legal action over alleged negligence, breach of contract, and breach of Australian consumer law.
Royal Caribbean said in a media statement to NZME that staff had been focusing on "providing care and support to passengers, their families and crew that were impacted".
It reiterated guests "were on an organised tour [White Island Tours] owned and operated by a local company that was independent from Royal Caribbean".
The 19-year-old was found in a remote area in the hills of Upper Hutt.