Kermadecs voyage #2: The mystery of the floating pumice

I was planning to write this personal blog at the same time as writing one for Scientific American, but I’m so busy circumnavigating islands in a RHIB, flying into volcanic craters in a Navy Seasprite, fishing for sharks off the back of the HMNZS Canterbury and helping rescue Kermadec storm petrels (it’s my job!) that I haven’t found the time. You can read my Scientific American blog posts but by all the media calls coming into the ship about the pumice raft we encountered a couple of days ago, I’m guessing that there might be a bit of interest in it (I have no internet connection here, just the ability to send out pre-arranged emails using a New Zealand military email addresses).

Just to summarise, here’s the story of the pumice, as I’ve posted on Scientific American’s expedition blog:

Wednesday 8 August 2012

“You can’t escape the geology in New Zealand,” said Helen Bostock, a marine geologist on the voyage. “It’s in your face whether you like it or not.”

It’s true. As we left Auckland this morning we were sailing away from two erupting volcanoes: Tongariro, in the middle of the Taupo Volcanic Zone, had just erupted for the first time in more than 100 years, depositing ash around the central North Island. White Island, a busy little volcano in the middle of the Bay of Plenty, was erupting ash from its Crater Lake.

So where are we heading? We’re sailing north along a chain of underwater volcanoes to another active volcano, Raoul Island, about two days sailing from Auckland. Raoul Island – the top 516 meters of a submerged volcano whose slopes extend for thousands of meters beneath the ocean – last erupted in 2006 and we hope it will stay quiet for our visit.

Thursday 9 August 2012: 

… at midday, our Commanding Officer, Commander Sean Stewart, gave the order to change course. A marine patrol aircraft, flying from Samoa to New Zealand, had spotted “an event” in the ocean north of us. Up to 250 nautical miles long by 30 nautical miles wide, it stood out against the blue-grey of the ocean as a great white froth on the surface of the sea.

Marine geologist Helen Bostock said the deposit could be a mixture of ash and pumice from an underwater volcanic eruption. There was only one way to find out – sample it. By the time we reached the deposit, the ash had dispersed, but blocks of pumice were bobbing past us in the water.

Commanding Officer Sean Stewart and Chief Petty Officer Henry Matangi with a big piece of pumice collected by Matangi. Photo by Helen Bostock.

Sometimes science is about using whatever tools you can find when faced with a serendipitous opportunity. At Helen’s request, a couple of young Navy ratings lowered buckets, tied to a rope, off the gun deck and down into the water. There was a big cheer when they came up with a few small pieces of pumice – brand-new, freshly-minted rock – in the bucket.

But from where? We have some people on board from Geonet, whose role is to monitor seismic and volcanic activity around New Zealand. They say that Monowai, an undersea volcano north of Raoul Island, has been showing activity for the past five days. Helen says that when she gets the pumice back to her NIWA laboratory, they will do a chemical analysis. “It’s like genetic fingerprinting,” she says. “Each volcano has it’s own chemical signature”. If this pumice matches Monowai, or one of the other existing volcanoes, that’s where it’s from. If it doesn’t match anything, it could be from a new volcano.

Friday 10th August 2012

Last night, when Lieutenant Tim Oscar, the Officer of the Watch, arrived at the bridge for his midnight to 4am watch (seriously, that’s what they do, all the lights on the bridge are turned off and they watch the sea) he noticed something strange. He turned the ship’s spotlights on and discovered the ship was ploughing through the wall of pumice we were looking for yesterday. The ship travelled through it for half a nautical mile, and he estimates it was two feet thick and extended sideways as far as the eye could see. “It was like being an ice-breaker hitting an ice shelf,” he said this morning. He described it as “the weirdest thing I’ve seen in 18 years at sea.”

It was too dark and the ship was going too fast to stop and take samples, so he noted down the latitude and longitude (29 59.43 degrees south and 179 25.598 degrees west) and motored on through it.

Saturday 11th August 2012

Helen Bostock with a handful of pumice collected off the side of the HMNZS Canterbury.

The engineering crew checked the ship’s water filters yesterday and, along with the usual mess of leaves and seaweed, they found a lot of small pieces of pumice. These filters, which suck in water to cool the ship’s engine, are about 10 feet below the sea surface, so when the ship went through the pumice raft on Thursday night it sucked up a lot of pumice with its water. Today, they’re giving the water filters a thorough clean. Helen Bostock has a new collection of pumice to take back to her lab in Wellington and I have a couple of small souvenirs to take home.

I’m transferring to Raoul Island tomorrow. If the weather packs in, as predicted, I’ll have time to write some more.

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Kermadecs voyage #1: On the HMNZS Canterbury

In 1955, when the US and USSR were involved in a nuclear arms race, the British Prime Minister asked New Zealand’s permission to test hydrogen bombs in the Kermadecs, a small group of islands about 800 km north of Auckland. Britain was looking for an uninhabited island, far from population centres and away from shipping lanes, and the Kermadecs filled the bill.

After considering the request, New Zealand’s Prime Minister Sidney Holland declined – it was an election year and the government thought the decision would be unpopular, saying it would be a ‘political H-bomb’ for New Zealand.

I’m glad he said no. For many reasons, but not least because I’m on the way there now. By sea. In a great big Royal New Zealand Navy ship, the HMNZS Canterbury, which looks as much like a big, grey, windowless building as it does like an ocean-going vessel.

HMNZS Canterbury. Note presence of helo pads and gun deck and absence of plunge pool, shuffleboard deck, cruise directors and cabin windows. Isaac the bar tender sadly not in attendance.

This is completely new to me. I’ve flown to Antarctica on a US Air Force C-17 Globemaster. I’ve crossed some of the world’s most dangerous and unpredictable stretches of water – New Zealand’s Cook Strait and Norway’s Maelstrom – but I’ve never been on an ocean voyage that latest more than three-and-a-half hours.

We are now all “embarked forces”. We’ve had safety and familiarisation briefings from the Department of Conservation and the Royal New Zealand Navy and I’m starting to learn what’s what. Left is port, right is starboard. Front is bow, back is stern. Gregory O’Brien, who went on an artists trip to the Kermadecs in May 2011, clued me up on some more of the lingo: it’s not a boat it’s a ship; it’s not a bed, it’s a berth; it’s not a map, it’s a chart. Before we sailed out of range, I got tweets to add to the list: it’s not a toilet, it’s a head (what’s that about?); it’s not a kitchen, it’s a galley. And I already know that it’s not a dining room, it’s a mess.

The view from the back of the helo deck. We now have an Air Force Iriquois on board.

Before we left, I signed forms to say I can swim 50 metres and run three kilometres in 25 minutes. I’ve affirmed that I have no joint or muscle problems that would affect my ability to “grip, reach, pull, push, squat, climb or jump”. All the sorts of things that would come in useful for outrunning an erupting volcano (I hope we won’t have to do that), leaping onto slippery rocks from an inflatable boat (that’s pretty much a definite yes – that’s the usual way onto Raoul Island), or keeping afloat if I end up in the water in one of our transfers from ship to boat to shore (again, hoping not to end up in the drink except for when we’re snorkelling).

I’ve come away with all sorts of advice for avoiding seasickness, like “take a keep cup and sip lemon and ginger tea on deck,” and for managing seasickness, from the useful “get horizontal with your head upwind”, and “Stugeron makes the dead walk,” to the no use at all “get rat arse on rum (the drunk are immune provided they stay drunk and do not get a hangover)” – this is a strict no-alcohol voyage.

But I’m sure there are barrels of rum hidden away somewhere. This is the Navy. While I’m searching for rum barrels, swearing sailors, and the ship’s cat, I shall ponder the question of why I had to tick a form saying I did not suffer from fear of flying, while there was no such question about fear of sailing.

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Why New Zealanders are so excited about the transit of Venus

The weather forecast for tomorrow’s transit of Venus is appalling. Cloud cover, rain, and gale force winds. But I was up in Tolaga Bay today – the focus of New Zealand’s celebrations of the transit – and the local Anglican priest, Stephen Donald, looked up at the sky, pointed to the sea, muttered a bit and said he thinks it’s going to be ok.

There are several reasons why we in New Zealand are so excited about the transit of Venus. First, if the cloud clears, we are one of the best-positioned countries in the world to observe the transit. We’re happy about this, because we completely missed the 2004 transit. Tomorrow, when the planet Venus starts to pass between the Earth and the Sun it will be 10.30am local time. And when Venus ends its transit it will be about 4.30pm. If the skies were clear (unlikely at the best of times) we’d get to see the whole thing.

The other reason we’re so excited is because a transit of Venus played a key role in our country’s history. After observations of the 1761 transit of Venus failed to result in a consistent calculation for the distance from the Earth to the Sun – the calculations were so varied that the observations were declared a failure – a successful calculation hinged on observations of the 1769 transit. London’s Royal Society sent James Cook to Tahiti where Cook set up a fort – Fort Venus – where Cook, astronomer Charles Green and botanist Joseph Banks all observed the transit on June 3, 1769, carefully recording the time of contact of the shadow of Venus against the sun. After observing the transit, Cook opened a set of sealed instructions from the Royal Society that directed him to sail south in search of Terra Australis Incognita, the unknown southern continent. If he was unsuccessful, he was to chart the islands of New Zealand then sail home.

“It’s an extremely symbolic event in the history of our country,” said the late Professor Sir Paul Callaghan, who described Cook’s landfall at Uawa/Tolaga Bay, where his men came ashore and communicated and traded with local Maori, as “the beginning of the dual heritage between Maori and European in New Zealand’s history”. And just as science played a role in that first contact, says Callaghan, it can play a key role in New Zealand’s future. As a consequence, a focus of the Transit of Venus conference taking place in Gisborne this Thursday and Friday will be how scientists and a science-based economy can make a difference to New Zealand’s future – in regions like the East Coast as well as in the big cities.

Even if you’re not coming to the forum you can have your say on New Zealand’s future by playing this online game, Pounamu – it works kindof like twitter, so register now and have your say on how you’d like science to play a role in New Zealand in 2022.

Sir Paul and I worked together last year to edit a special issue of the Journal of the Royal Society of New Zealand, themed around the transit of Venus. The issue, which has just been published, has articles about Jeremiah Horrocks, first contact between Maori and European, Banks and Solanders’ botantical and zoological collections in New Zealand, Polynesian and European navigation systems, the 1874 transit of Venus as observed from New Zealand, and more. The entire issue is downloadable for free until 31 July this year.

So … fingers crossed for a sight of the Sun tomorrow!

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Of noddies, humpbacks, tubeworms and sea mats

Late last year I wrote an essay about the science and history of the Kermadec Islands for a gorgeous new book, Kermadec. I was just getting an excerpt from it ready to post when I heard that a Department of Conservation volunteer was missing off Raoul Island, presumed dead, probably the victim of a freak wave. Awful. Mihai Muncus-Nagy was from Romania, he was passionate about conservation and had always wanted to visit New Zealand and its beautiful outer islands.

These islands are wild. Another Department of Conservation worker died there in 2006 when the Raoul Island volcano erupted while he was taking temperature measurements at Green Lake.

I’ve never been to the Kermadec Islands, but when I was writing my essay last year, I immersed myself in the topic, and spent several days sitting in a glass-fronted house in Seatoun, while it rained outside, seabirds dived in the wind and waves crashed against the beach across the road.  A perfect setting to be writing about a group of islands and the marine sanctuary around them. There are calls for the Kermadec Islands and the waters around them to be made an ocean sanctuary, to protect the entire area from fishing and mining, and Pew Environment Group, who published the book, are leading the call.

You can buy Kermadec at Unity Books and Parsons Bookshop if you live in Wellington or Auckland or directly from Pew Environment Group if you don’t. It’s a beautiful book, with photographs as well as art from the group of artists who travelled to the islands last year – Gregory O’Brien, Phil Dadson, Bruce Foster, Fiona Hall, Jason O’Hara, John Pule, John Reynolds, Elisabeth Thomson and Robin White – hard cover, full colour and only $40!

Here is a slightly abriged excerpt from my 3000 word essay that appears in the book. Unusual for me, this time I got to write about critters.

A line in the ocean
On Raoul Island, tuis and red-crowned parakeets forage for nectar and insects in the pohutukawa and nikau that blanket the mist-shrouded slopes. Near the centre of the island, a caldera – a depression formed by land subsidence after a large eruption – holds three lakes that are home to the island’s grey ducks and pukeko. The smallest, Tui Lake, is a pond nestled in the bush, but Blue Lake is large enough for swimming and, until a 1964 volcanic eruption deposited sediment in the lake, was a fresh water source for the island’s meteorological camp.

Green Lake 2011, Elizabeth Thomson, acrylic, optically clear epoxy resin, glass spheres on wood panel, 1200 x 1200 x 30mm

The eruption came from Green Lake, Raoul Island’s steaming volcanic crater, where it’s said that the alkaline water will erase your fingerprints in 10 minutes. The Raoul Island volcano remains active. In 2006, a Department of Conservation worker was killed when the volcano erupted while he was taking a temperature measurement from Green Lake. The 30-minute eruption – the first in more than 40 years – came without warning and deposited metres of ash, mud and rocks around the lake. There have been no eruptions since, but earthquakes are an almost daily occurrence.

Raoul, with its fresh water and cloud forests, is the only island in the Kermadec group with a human settlement. The rest of the islands belong to the seabirds. Six million birds breed on the islands, and twice that many – representing more than 40 other species, including albatrosses, prions, petrels, and frigatebirds – frequent the area. While some seabirds make annual visits to the islands from breeding sites in Siberia and Alaska, 14 species breed in the islands, building their nests in branches of trees, high on cliffs, on rocky ledges and in crevices and underground burrows. Three of the nesting species are endemic – the Kermadec storm petrel, the Kermadec little shearwater and the white-naped petrel. Now that the rats are gone, the bird population is growing.

Some birds, the pelagic species, forage widely. A black-winged petrel was tracked travelling to Tonga and the Chatham Islands, a round trip of 3000 km, before returning to the burrow to feed her chick the oily mix of digested squid, krill and fish she had gathered. Other birds, like the small noddies and storm petrels, stay close to the islands, where they feed on tiny fish eggs, larvae and crustaceans from just beneath the water’s surface; or dive for squid, wings outstretched, as if in flight.

The endless sea
The ocean around the Kermadec islands, once a favourite with whalers, is now home to at least 35 species of whales and dolphins, many of them vulnerable or endangered. Bottlenose dolphins now frolic around the islands while families of sperm whales and mother and calf humpback whales pass by in their hundreds on an annual migration to Antarctic feeding grounds. Alongside them, critically endangered giant leatherback turtles, far from their tropical nesting sites, paddle through the deep water in pursuit of their jellyfish prey. Smaller green and hawksbill turtles forage in shallower waters closer to shore.

For 12 nautical miles around each island, the waters are protected, part of a marine reserve from which no species may be taken. These waters provide a sanctuary for a unique mix of tropical, sub-tropical and temperate species of fish. This is a rare ecosystem, where large predators rule, untroubled by fishing lines or nets. In the shallow waters, the Galapagos sharks and the spotted black grouper swim fearlessly. Deeper down the spiny dogfish competes with bass and bluenose for the tastiest prey.

Raoul Island is only the top 516 metres of a submerged giant volcano whose slopes extend for thousands of metres beneath the ocean. On the submerged flanks of the volcano, giant limpets park on the rocks, and anemones wave their multi coloured tentacles in the crystal-clear waters, gathering and grazing on passing plankton. Strange and wonderful species of corals, crustaceans, and molluscs make up a complex ecosystem that scientists are only beginning to understand.

The zone of imagination
Around the islands, deep beneath the ocean, is an undersea world of seamounts, trenches, black smokers and strange exothermic species that stretch the limits of the scientists’ imagination.

The Kermadec Islands stretch over 2 degrees of latitude, or 250 km. But in recent years, exploration of the ocean between New Zealand and Tonga has revealed that these islands are part of a 2500 km chain of mostly underwater volcanoes. This line of mountains – the longest underwater volcanic arc on the planet and the most hydrothermally active – is the result of a collision between the Pacific and Australian Plates. On the east side of the collision zone is the Kermadec-Tonga Trench, a slash in the ocean floor that extends 10,800 metres deep and into which no one has seen. West of the trench, stretching from New Zealand’s Bay of Plenty to Tonga, are more than 50 underwater volcanoes and the Kermadec Islands.

A crown for the Kermadec King 2011, Gregory O'Brien, acrylic on canvas, 460 x 460 mm

Scientists are only just beginning to learn about these underwater volcanoes, or seamounts, which were discovered in the 1990s. Recent underwater excursions, by deep sea submersible, have found widespread volcanic activity in the form of diffuse hydrothermal vents, where gas-rich hot water flows into the surrounding sea, and black smokers, where high pressure plumes of super-heated, mineral-rich water jet out of the rock, leaving chimney-like deposits of heavy minerals like iron and manganese, copper and gold.

Some of the strangest creatures in the Kermadecs exist around the hydrothermal vents. Living so far from sunlight, with no opportunity to photosynthesise, these “chemosynthetic” species draw energy from chemicals and minerals in the hydrothermal fluids. Around the vents are forests of stalked barnacles and clumps of giant mussels that provide food for predatory starfish and gastropods. Tiny orange shrimps swarm towards the warm waters where hot vent fluid mixes with the cool sea. Among the many odd creatures are the giant tubeworms, with their symbiotic bacteria that turn hydrogen sulphide – a poison to many species – into food. On top of the vent mussels, strange and tiny marine animals called bryozoans, whose intricate structures can only be seen through powerful microscopes, form colonies of hermaphrodite clones. Other species of bryozoan are found throughout the Kermadec waters – from the shallow waters around the islands to 8000 metres down the Kermadec Trench. The scientists who first named these creatures had an creative bent, and their names are rich with metaphor: different types of bryozoan are known as lace corals, moss animals, or sea mats.

The first major scientific exploration of the Kermadec Islands was in 1908, when New Zealand naturalist Walter Oliver led a small group of scientists in a year-long exploration of Raoul Island’s flora, fauna and geology. More than 100 years later, visiting geologists and biologists are still making discoveries about this remarkable group of islands and the ocean that surrounds them. Even so, the Kermadec region remains the least explored of all of New Zealand’s waters, and every visit yields new discoveries. In 2011, a group of plant, fish, shark and ecology specialists travelled to the Islands on a biodiscovery expedition that revealed new marine species, like the brilliant orange zebra fish, a small left-eyed flounder and a silver flying fish that landed on the boat in front of a surprised photographer.

Shoot the Breeze, 2011, Fiona Hall, tin and video, 230 x 190 x 30mm

Just as the biology and geology of the Kermadecs have long inspired scientists, who have shared their understanding of this world through scientific articles, lectures and photographs, the islands have now inspired a group of artists, who are sharing their experiences through poetry, paintings, sculpture and music.

Science and art might seem, at first glance, to be two different worlds, but in these islands the disciplines intersect, with both artists and scientists diving into this new environment, driven by a desire to discover, to interpret, to see things no one has seen before. Art and science merge when a scientist lovingly renders a map or an illustration, or carefully frames a photograph, or when an artist spends hours watching a bird or a fish, immersing herself in her subject and obsessively recording every detail. Beyond the specialist languages of science and art, the visitors use a common language, describing the Kermadecs as “exhilarating”, “spectacular” or “stupendous”; “a frontier of wonders” that’s “better than my imagination”; a “classroom”, a “mystic garden” that’s “wonderful and frightening”. But there’s one word that comes up more often that most. Again and again, visitors refer to the islands and the marine ecosystem as “pristine”. To scientists, this pristine, unspoilt environment is a “baseline of normality” that shows us what the world was like before humans began changing the planet.


For artists and scientists, the Kermadec Islands, where birds fly underwater and fish jump into the air, where black smokers spew into the sea and earthquakes shake the land, are a place of imagination and inspiration. For the seabirds, sea creatures and marine mammals that live on and around the islands, they are a safe passage from breeding grounds to feeding grounds or, to many species, home.

But at the same time as new underwater species and ecosystems are starting to be documented – many of them weird and wonderful, and some of them endemic to the Kermadecs – they are under threat. The Kermadec Islands Marine Reserve, established in 1990, protects the waters near the islands, but outside of the 12 nautical mile no-take zone around the islands, fishing boats gather to net species shoaling above the newly-discovered seamounts, and mining companies fund exploration to assess the seafloor for minerals like gold, copper and lead.

Ghost Net 2011, Fiona Hall, Tongan tapa dye, ochre on barkcloth, 2040 x 2400 mm

Our planet is currently in its biggest mass extinction for 65 million years. If we want to protect our planet’s biodiversity – which scientists believe is essential for the health and resilience of our earth ecosystem – this pristine group of islands, and the expanse of ocean around them, is a great place to start. There are not many “baselines for normality” left on this planet. Let’s protect the ones we still have.

You can find out more about the campaign to protect the waters around the Kermadec Islands at The Pew Environment Group’s Global Ocean Legacy site.

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Antarctic playlist update

Before I went to Antarctica I asked people for recommendations on music to listen to while there, and I put together an Antarctic playlist.

Turned out I didn’t listen to much music while I was in Antarctica. It was too noisy in the C-17 flight down (those in the know were wearing noise cancelling ear muff thingies) and the rest of the time I was too busy being in Antarctica. Around Scott Base and McMurdo the soundscape was helicopters, monster trucks and wind turbines. On walks around the pressure ridges there was the gentle sound of flags flapping and whipping in the wind and the occasional sear roar. On bigger walks, though, when I wasn’t listening to the silence I did sometimes listen to music, and these are the songs that now evoke Antarctica best for me.

1. Glosoli by Sigur Ros for the endless trudging beat that goes through the song that echoed the sound of my boots trudge, trudge, trudging in the snow.

2. Holocene by Bon Ivor for the line “I can see for miles and miles and miles”.

3. A new song, that wasn’t on my list, but Alice played it to me while we were at Scott Base and sent me when we got home: Our Retired Explorer (Dines With Michel Foucault In Paris, 1961) by The Weakerthans. I smile every time I hear it. As well as just being a great song it manages to capture the foolish and fun aspect of our time in Antarctica: sometimes the only response to being somewhere so amazing and incredible – we’re in Antarctica! – was a bit of inappropriate giggling and we managed plenty of that.

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Alice’s Antarctic diaries

On my recent trip to Antarctica, my fellow writer and near-constant companion was Wellington poet and all-round writer person Alice Miller. We shared a bunk room together, made each other many coffees, bought each other many drinks, and went on daily excursions to visit historical huts and remote field stations and to have adventures like camping on the sea ice, cross-country skiing and ice fishing.  Best of all though, we walked. Sometimes with other new friends and sometimes just us, often walking close enough to each other to be safe in the case of sudden whiteout but far away from each other enough to have the sense of being alone in the Antarctic whiteness. I think it was in those almost-alone times that we each did the most writing.

Alice and Rebecca walking on the sea ice near Scott Base. Photo by Dr Nick Golledge.

While Alice was in Antarctica she kept an audio diary. I seemed to be constantly interrupting her while she was speaking but thankfully, that’s not on tape. Her Antarctic diary has been playing on Radio New Zealand’s Summer Nights. I’ve enjoyed listening to them over the last week or so. I’m fully immersed in my Wellington life now and it’s wonderful to be reminded of what we were doing just a month ago – to be reminded that it was real.

Here are links to her audio diary posts. Each entry is just a few minutes long:
Alice Miller Antarctica audio diary 1
Alice Miller Antarctica audio diary 2
Alice Miller Antarctica audio diary 3
Alice Miller Antarctica audio diary 4
Alice Miller Antarctica audio diary 5
Alice Miller Antarctica audio diary 6
Alice Miller Antarctica audio diary 7

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