Our Changing World

Emperor penguin researchers are waiting for tagged birds to return, and an elderly radar system sheds light on a very windy part of the atmosphere.

A team of NIWA researchers spent a month with a couple of thousand Emperor penguins at Cape Crozier on Ross Island, in Antarctica, during November 2019.

They were hoping that high-tech data loggers glued to the birds' backs would shed some insights into their journeys and feeding habits out at sea amongst the pack ice.

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The Cape Crozier emperor penguin colony is being studied by a NIWA team as part of the Ross Sea research and monitoring programme, known as Ross RAMP. The programme is monitoring the effectiveness of the very large Ross Sea marine protected area.

The team, led by Gitte McDonald from the Moss Landing Marine Laboratory, attached video cameras and biologging data tags to 19 breeding birds to study their foraging at sea: where they were going, how often they dived and what they were eating.

Unfortunately, five of the tagged birds didn't come back before the researchers had to leave; these birds included four of the five birds carrying video cameras.

The tags that were retrieved revealed that individual birds travelled to quite different locations - four went east from the colony, but some went west around the northern tip of Ross Island.

The longest foraging trip was 18 days, and in that time the bird travelled at least 250 kilometres in each direction, although its overall journey would have been much further than that.

It was also diving frequently in search of food - as well as many shallow feeding dives it made regular dives to more than 250 metres, when it was probably feeding on the sea floor.

Gitte says this is the first time that Emperor penguins from Cape Crozier have been studied in detail and they are making some of the longest feeding trips and deepest dives recorded for the species.

The adult bird can put on two kilograms in weight during a trip, and feeds most of that to its rapidly growing chick which needs to be fully feathered and independent by the time the sea ice where the colony is situated breaks up.

Long-term monitoring of the atmosphere

Adrian McDonald and colleagues from the University of Canterbury maintain an MF radar at Arrival Heights, near Scott Base, that allows them to gain insights into one of the windiest parts of the atmosphere…

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Alison Ballance meets a colony of Emperor penguins and their NIWA researchers, and finds out about making water on the frozen continent

Back in 1911, a party from the Scott's Antarctic expedition made the 'Worst Journey in the World' - a midwinter sledge haul to collect eggs from the first Emperor penguin colony ever discovered, at Cape Crozier on Ross Island.

Alison Ballance, on the other hand, reckons her early summer trip to meet the Emperors and the NIWA team studying them, is the 'best journey in the world', although she discovers that the penguins are keeping the researchers waiting.

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Apsley Cherry-Gerard wrote the book 'The Worst Journey in the World'. It was about the trials and tribulations he faced back in 1911, along with Edward Wilson and Birdie Bowers.

The three men made the 120-kilometre trek to Cape Crozier in the midwinter dark. It was bitterly cold, their teeth cracked and their sleeping bags and clothes were almost permanently frozen solid.

They found the penguins incubating their eggs through the winter and collected some to take back for study.

Emperor penguins are the largest penguin species, and they breed on the annual sea ice in about 54 colonies around the edge of Antarctica. It is estimated there are about 238,000 breeding pairs.

Emperor penguins incubate their eggs on their feet and don't have a nest. They breed in a large huddle of birds which slowly moves as the birds take turns staying warm in the centre of the group.

Emperor penguins find their mate and chick in the colony by the sound of their call; each bird has a unique call.

The Cape Crozier emperor penguin colony is being studied by a NIWA team as part of the Ross Sea research and monitoring programme, known as Ross RAMP. The programme is monitoring the effectiveness of the very large Ross Sea marine protected area.

There were four Ross RAMP projects taking place in the Ross Sea during the 2019-20 summer: Emperor penguins, past and ancient Adelie penguin colonies and Weddell seals.

The Emperor penguin team was led by Gitte McDonald from the Moss Landing Marine Laboratory. The researchers attached video cameras and biologging data tags to 19 breeding birds to study their foraging at sea: where they were going, how often they dived and what they were eating.

Water, water everywhere but not a drop to drink

In the field in Antarctica, researchers melt snow or ice to make water. The blocks of snow stacked around the blue tent in the photo above are the water supply for the Cape Crozier field camp…

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Keeping Scott Base warm and well-lit no matter the weather outside, and a physics experiment that eavesdrops on messages to submarines.

Small coloured flags fluttering atop bamboo poles are a familiar sight in Antarctica, marking safe routes for travel on the sea ice, where cracks and thin ice can pose a danger.

The way they flutter is a good unofficial barometer for how strong the wind is, but the official Ross Island weather designation varies from Condition 3 - normal conditions - up to Condition 1 - when temperatures are so low and wind so strong that people are confined to base.

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In the Antarctica Specially Protected Area at Arrival Heights, located between Scott Base and McMurdo Station, physicists from the University of Otago maintain a VLF (Very Low Frequency) radar to eavesdrop on communication signals sent to submarines.

These VLF signals travel for thousands of kilometres and bounce off the ionosphere, and Antarctica is a great place to detect them. The physicists use the signals to study sun flare activity.

Lightning strikes are also detectable in the very low frequency range, and the University of Otago Space Physics Group also maintains a lightning detector at Scott Base that is part of a global lightning detection network.

Voices from Antarctica - listen to the full series

Voices from Antarctica 1: Ice Flight

Voices from Antarctica 2: Scott Base

Voices from Antarctica 3: Flags to physics

Voices from Antarctica 4: Best journey in the world

Voices from Antarctica 5: Waiting for Emperors

Voices from Antarctica 6: Seal songs

Voices from Antarctica 7: What the ice is saying

Voices from Antarctica 8: Under the ice

Our Changing World's Antarctic collection

Listen to a wide range of stories recorded in and about Antarctica from our archives.

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Alison Ballance has her first day at New Zealand's Antarctic station, Scott Base, and visits the historic Hillary's Hut.

In the Scott Base episode of Voices from Antarctica, Alison Ballance gets some tips on how to sleep warmly and go to the toilet out in the field, and gets a tour of Hillary Hut with Antarctic Heritage Trust conservator Al Fastier.

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Scott Base is New Zealand's Antarctic station, situated at Pram Point, Hut Point Peninsula on Ross Island in McMurdo Sound. Its exact location is 77°51'S and 166°46'E, and it is 10 metres above sea level. The United States' McMurdo Station lies a few kilometres away.

Hillary Hut, was known as Hut A in the original Scott Base, and was constructed as a kitset in January 1957.

It is officially known as the TAE / IGY hut. This stands for the Commonwealth Trans-Antarctic Expedition - International Geophysical Year.

Hillary's Hut now serves as a museum.

Hillary Hut was built to house a team of New Zealanders, led by Sir Edmund Hillary, who were supporting Sir Vivian Fuchs' effort to cross Antarctica. Sir Ed and his team were just meant to lay supply depots for Fuchs, but they ended up driving all the way to the South Pole in Massey Fergusson tractors where they met 'Bunny' Fuchs and his team who had crossed from the other side of the continent.

The original Scott Base was intended to be a temporary camp only, but in 1962 the New Zealand government decided to make it a permanent Antarctic Base.

Over time, the old base has been mostly replaced by new buildings.

The Antarctic Heritage Trust has recently restored Hillary's Hut, as part of a multi-year mission to restore five historic huts in the Ross Sea region.

https://www.instagram.com/p/B_0rqvaA1pk/

In 2011, Alison Ballance reported on the restoration of Shackleton's Nimrod Hut at Cape Royds.

In 2007, Veronika Meduna reported on the restoration of the Nimrod Hut and Scott's Hut at Cape Evans.

Voices from Antarctica - listen to the full series

Voices from Antarctica 1: Ice Flight

Voices from Antarctica 2: Scott Base

Voices from Antarctica 3: Flags to physics

Voices from Antarctica 4: Best journey in the world

Voices from Antarctica 5: Waiting for Emperors

Voices from Antarctica 6: Seal songs

Voices from Antarctica 7: What the ice is saying

Voices from Antarctica 8: Under the ice

Our Changing World's Antarctic collection

Listen to a wide range of stories recorded in and about Antarctica from our archives.

Go to this episode on rnz.co.nz for more details

Alison Ballance dons her extreme cold weather clothing for a trip to Antarctica - but getting to the frozen continent can take time.

Our Changing World producer Alison Ballance dons her extreme cold weather clothing for a trip to Antarctica - however, she soon discovers that it's all very well to be dressed and ready to go, but getting to the frozen continent can have its logistical challenges.

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I got the opportunity to travel to Antarctica as part of Antarctica New Zealand's community engagement programme.

Antarctica New Zealand represents New Zealand's interests in Antarctica and provides logistical support to a number of different science programmes.

In the 2019-2020 season they supported 18 science projects, ranging from microbes on Mount Erebus to climate change research, with about a hundred scientists involved, from New Zealand and from overseas.

Logistical support includes travel to and from the ice, accommodation - either at Scott Base or in a field camp - as well as a full kit of clothing to cope with sub-zero conditions.

Antarctica New Zealand manages Scott Base, which is situated on the southern tip of Ross Island, in the Ross Sea sector of western Antarctica. The base is just a few kilometres away from the largest base in Antarctica, the USA's McMurdo Station.

Antarctica New Zealand and the United States Antarctic Program share flights to and from the Phoenix runway, which is a permanent year-round runway located on the Ross ice shelf, not far from Scott Base.

The US Air Force flies C17 Globemasters, and both New Zealand and the US also fly Hercules to the ice.

The C17 is a wide-bodied cargo plane with a payload of 100,000 pounds. It can carry up to 130 people, or cargo such as large machinery and helicopters.

Antarctica New Zealand logistics co-ordinator Paul Woodgate says travelling to Antarctica is not like normal air travel, and that the "Antarctic factor" means delays are not uncommon.

Weather is the most common reason that flights are delayed. If weather conditions change while a plane is en route it may have to 'boomerang' and return to New Zealand.

Mechanical faults with the C17s were an issue in the 2019-2020 summer season, and I experienced a delay of a week getting to the ice for my visit. The longest delay that Paul has had to deal with was 16 days…

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Two gems from Our Changing World's Antarctic archive - restoring Shackleton's hut at Cape Royds and hunting for extremophile microbes high on Mt Erebus.

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Experts discuss the findings from a recent NIWA report that shows a small amount of sea-level rise will cause more coastal flooding.

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Scientists warn that a small amount of sea-level rise could have big consequences for some low-lying parts of New Zealand.

Scientists warn that a small amount of sea-level rise could have big consequences for some low-lying parts of New Zealand.

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NIWA coastal scientists Dr Scott Stephens and Dr Rob Bell are co-authors on a recent paper which concludes that small increases in sea level rise are likely to drive huge increases in the frequency of coastal flooding in the next 20-30 years.

The researchers analysed more than a century's worth of extreme sea-level and storm surge events to look for patterns in the timing and occurrence of damaging coastal flooding and found that the worst events happened when a number of factors coincided.

Sea-level 101

There are a number of things that have an effect on sea-level over different time frames.

Sea-level changes over the course of year due to temperature - it is slightly higher in summer as warmer water expands.

"It's not a big fluctuation, just 10 centimetres or so, and yet surprisingly it has quite a strong control on when we observe our highest sea-levels," says Scott.

Every day, sea-level changes with the tides, rising and falling up to four metres around Nelson and less in other parts of New Zealand.

But not all tides are equal; tide height varies with the lunar cycle, and every fortnight spring tides, which coincide with the full and new moons, have a wider range than the intervening neap tides.

Extra-high tides known as king tides occur every seven-or-so months. These are the result of the moon's 29-day elliptical orbit around the earth. These are predictable and NIWA publishes an annual red-alert tide calendar for king tides.

On their own, king tides can cause sunny day flooding in low-lying areas. Nelson's Wakatu Square is susceptible to this nuisance flooding as seawater encroaches up stormwater drains during a king tide and floods the carpark.

"This nuisance flooding is what we're going to see a lot more of due to sea-level rise," says Scott.

However, trouble really arrives in the form a storm surge coinciding with a spring or king tide.

"When we get stormy weather systems with strong winds, the winds push the water up against the land surface, causing ... a storm surge," says Scott.

Scott and Rob's analysis of past coastal flooding events showed that the most damage was usually the consequence of an extreme high tide coinciding with a moderate storm surge.

The sea is going up…

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Ocean floor rock cores drilled into the sunken continent of Zealandia are revolutionising our understanding of Earth's history and how continents form.

Ocean floor rock cores drilled into the sunken continent of Zealandia are revolutionising our understanding of Earth's geological history and how continents form.

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Zealandia might be a hidden continent, but it is twice as large as India. It surrounds New Zealand and stretches north to New Caledonia and south beyond subantarctic Campbell Island.

Professor Rupert Sutherland, from Victoria University of Wellington, says "it was really discovered in the 1960s and 1970s through seafloor mapping." In 1972, three rock cores were drilled into the seafloor, revealing rocks that were continental in nature.

But despite its size it is a newcomer in being recognised as a continent. It was formally recognised, scientifically in 2017, having already been acknowledged legally under the United Nations Convention on the Law of the Sea.

Unlike the world's other continents, which are mostly above water or covered in shallow water, nearly 95 percent of Zealandia is underwater, at depths of a kilometre or more.

"What makes New Zealand different is that so much of it is underwater," says Professor Gerald Dickens, from Rice University in the United States.

In 2017, for the first time in nearly 50 years, an International Ocean Discovery Programme expedition aboard the JOIDES Resolution drilled at six carefully chosen sites to gather evidence that could answer questions about how Zealandia formed and also how other continents formed.

It has been known for a few decades that New Zealand began separating from Australia and Antarctica, which were all part of the ancient continent of Gondwana, about 100 million years ago. This separation stopped about 50 million years ago.

'That's where the history of Zealandia gets truly fascinating," says Gerald.

"It starts going through compression and uplift, so parts of Zealandia are going up and parts are going down, and it becomes a very complicated continent."

Rupert says that what is becoming clear is that these upheavals between 50 and 20 million years ago were in some way related to the Pacific Ring of Fire.

The Ring of Fire is related to the process of subduction, a process where a tectonic plate "subsides and sinks deep into the earth's mantle," says Rupert. The result is an active zone of volcanism and tectonic activity…

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Geologists are probing the secrets of the hidden continent of Zealandia, and ants and viruses from the archives.

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