Our Changing World

Information from past earthquakes can be used to prepare a more resilient society that will be better able to cope with future shakes.

University of Canterbury earthquake engineer Brendon Bradley says we can't predict when and where earthquakes will occur, but "we do have probabilistic models that tell us the likelihood that certain faults are going to rupture over a certain period of time."

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Brendon is the Director of QuakeCoRE - the New Zealand Centre for Earthquake Resilience. It is a Centre of Research Excellence that involves researchers from a wide range of organisations.

Brendon says resilience means "treating the entire earthquake pipeline from occurrence - how can we better understand where and when earthquakes occur - to the ground-shaking, the damage to buildings and other infrastructure, and then how society responds to that damage."

"Ultimately it's how we can reduce damage in the first place and how we can make society more resilient so that we can cope with the inevitable damage to a better degree."

Brendon has been in Christchurch for the past decade and he says his 'professional career has been shaped by the earthquakes", from the 2010 Darfield and 2011 Christchurch quakes to the 2016 Kaikōura quake.

As an earthquake engineer the quakes provided opportunities close to home to study the mechanisms and aftermath of large earthquakes.

"Large earthquakes don't happen very often and as researchers we always immediately try to get out into the field, because there's really no substitute for learning from observations."

There was significant ground-shaking in all three earthquakes, which happens to be Brendon's area of research.

It provided opportunities for "analysing the ground shaking and understanding how consistent that is with models we use to predict ground shaking for the future."

Brendon and colleagues produced a simulation of the ground-shaking that occurred during the 2016 Kaikōura earthquake. It has been intercut with footage recorded by CCTV in an office building in Wellington.

https://www.youtube.com/watch?v=j9c-Fwhaigc

While it is not possible to predict the timing and location of future earthquakes, QuakeCoRE researchers are involved in predicting future earthquake scenarios and their consequences…

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When it comes to having a 'good life', there are several key elements - strong intimate relationships and time to relax.

The secrets to a good life are as simple as a strong intimate relationship and plenty of rest, says Victoria University of Wellington psychologist Joseph Bulbulia.

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More than 40,000 New Zealanders take part in the New Zealand Attitudes and Values Study. They regularly answer hundreds of carefully thought-out questions, posed by a team of researchers who are interested in a wide range of topics.

Joseph studies people and their lives outside work, with a focus on New Zealand society.

"I'm interested in what makes life good," says Joseph. "What are the things that lead people to have a rewarding, satisfying, meaningful life."

"Some of the surprising outcomes in the study have been, for me, the role of relationships," says Joseph. "Much more so than making lots of money, or gaining promotion, or having a child."

"We find people who are in relationships tend to report much greater satisfaction, much lower anxiety and distress."

Joseph is quick to acknowledge that negative relationships can also be anxiety-provoking and distressing, but says that on average "it's those personal relationships, in particular romantic ones, that tend to make people - on average - happier across society."

"And the magnitude of the effect is massive."

Silver lining to the lockdown

Joseph says he is also interested in the role that relaxation and "ease of effort" contribute to a sense of living a good life.

This came out of research carried out during New Zealand's covid lockdown in early 2020.

He says the majority of people surveyed were not as challenged by the situation as the researchers had expected.

Many people reported "a sense of relief from the daily grind," commenting that they were getting more sleep.

"Turning down the volume of the ordinary routine helped us to feel relief and then to cope with the extraordinary challenges," says Joseph.

"We see the coming together of rest, relaxation and relationship in that first lockdown."

"The distress that we do detect in the population at that time was happening in that subset of the population that was experiencing relationship challenges."

Further listening

Biggest risk to ageing well is loneliness - listen to Yoram Borak talking about the power of social relationships in helping us age well.

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Cancer epidemiologist Brian Cox, from the University of Otago, talks about studying the causes of cancer and new research on diet and bowel cancer.

A new study from cancer epidemiologists at the University of Otago reveals that eating dairy products and a low-fat diet can reduce the risk of bowel cancer.

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Diet has long been known as a risk factor for bowel or colorectal cancer, but the new study, by Mary Jane Sneyd and Brian Cox, from the Hugh Adam Cancer Epidemiology Unit at the Otago Medical School, is the first to specifically examine the role of diet as a cause of bowel cancer in New Zealand.

The report showed that "higher than average" consumption of lamb, pork and bread and processed meat such as salami and sausages, was associated with an increased risk of bowel cancer.

For the first time it was found that dairy products - but not cheese - and a low-fat diet were associated with a reduced risk, which may offset the elevated risk from meat consumption.

A reduced risk of bowel cancer was also found with a history of vigorous exercise.

"There are several risk factors for bowel cancer and their relative contribution to the disease differs among countries and between regions within countries," says Brian.

"Therefore, the prevention of bowel cancer here requires New Zealand specific knowledge of the relative contribution of the risk factors for bowel cancer, which is vital for the control of bowel cancer in New Zealand.

Contrary to previous research, this study found greater than average consumption of fresh fruit or vegetables did not significantly reduce the risk of bowel cancer and no reduced risk was found for vegetarians or vegans.

The case control study drew on data from the New Zealand Cancer Registry, and questionnaires completed by 806 bowel cancer patients, aged between 30 and 74-years-old and 1025 people matched as controls.

Brian says that New Zealand has very high rates of bowel cancer, although rates vary considerably by birth year. People born between 1940 and 1956 have less than half the rate of bowel cancer compared to people born earlier. But since 1956 rates have risen again.

Listen to the full podcast to hear Brian talk about cancer epidemiology and why it is important to investigate the causes and risk factors associated with cancer, as well as the effectiveness of various screening and treatment programmes.

You can listen to Brian Cox and Mary Jane Seyd talk about melanoma in an earlier Our Changing World interview.

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How river water reaches out to sea and an epidemiologist talks about work into the causes of cancer.

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Two self-driving underwater robots are making surprising discoveries about where river water ends up at sea, far from land.

Autonomous ocean gliders that measure New Zealand's coastal seas have detected eddies of river water more than one hundred kilometres away from their source.

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Rivers discharging plumes of sediment-rich freshwater into the ocean are a common sight around the New Zealand coast.

But it has taken two ocean robots, named Manaia and Betty, to reveal just how far offshore eddies of this freshwater can travel.

Joe O'Callaghan is a coastal oceanographer NIWA and the Sustainable Seas National Science Challenge. She says that in the past few years the underwater gliders have been carrying out repeated surveys of greater Cook Strait.

The gliders measure salinity, turbidity, temperature and chlorophyll, and Joe says they detected a distinct salinity signature much further offshore from Golden and Tasman bays than previously recorded.

Four rivers feed into these bays, with the Aorere and the Motueka being the largest.

Joe says that traditionally it was thought that water from these rivers would be moved by tides and wind, causing them to meander and shed different sized 'blobs' of rotating water or eddies that carry nutrients and sediment offshore. The idea was that it "would mix locally and just not have a very substantial signal outside of the bays."

"Instead we've got some quite significant far-field signals," says Joe.

The freshwater eddies are about four to ten kilometres across, and last from a few hours to a few days, depending on the strength of the D'Urville current which varies in intensity and direction.

University of Auckland PhD student Khushboo Jhugroo says these eddies "connect the land and the ocean."

"What's new with this study is that it's taking this connection much further out to sea than we previously know," says Khushboo.

The freshwater eddies are buoyant and float on the surface where sunlight can reach them, which means the often nutrient-rich freshwater may contribute to phytoplankton blooms and general ocean productivity.

"The glider observations are more effective at tracking rivers than satellites because they can map the ocean in all weather conditions and at much better resolution", says Joe.

"Betty and Manaia detect not only temperature, like satellites, but also salinity which was key to seeing these eddies."…

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NIWA experts explain the science behind this year's large ozone hole and New Zealand's high UV levels.

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NIWA's Richard Querel talks about the ozone hole, including this year's large one, and Ben Liley explains why NZ has such high UV levels.

The 2020 Antarctic ozone hole is one of the largest and deepest of recent years, due to stratospheric weather conditions trapping cold air high above the frozen continent.

This year also saw the first significant ozone hole appear over the Arctic.

But overall, scientists say the ozone layer remains on a path to recovery.

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The thinning of the ozone layer over Antarctica each southern spring was first detected from the ground in the early 1980s.

The first measurements that showed ozone depletion were made using a Dobson ozone photospectrometer, a machine developed in 1924.

About 120 were built and about 50 are still in use around the world today. There is a Dobsonmeter at Arrival Heights near New Zealand's Scott Base and another at NIWA's Lauder Research Station in Central Otago.

In 1983, the first satellite image of the ozone hole as seen from space was made, and the discovery of the ozone hole was published in 1985.

Scientists think of ozone as a column extending from the earth's surface to the top of the atmosphere. It is measured in Dobson Units.

Average global levels of ozone are about 300 Dobson Units, and an ozone hole is defined as an extended period where ozone is less than 220 Dobson Units.

Ozone levels over Antarctica shrunk to a record low of 89 Dobson Units in 2006.

The annual ozone hole varies in size considerably from year-to-year, depending on regional weather conditions in the stratosphere. Extreme cold creates the right chemical conditions for increased ozone destruction.

The 2020 ozone hole is one of the largest and deepest of recent years.

On 6 October this year, ozone levels got down to 94 Dobson Units,

NOAA and NASA report that at its peak on the 20 September the hole covered an area of 24.8 million square kilometres, the size of North America. There was virtually no ozone in a 6.4-kilometre-high column of the stratosphere over the South Pole.

However, in terms of ozone holes over the past four decades, this year's persistent ozone hole - which started forming in mid-August and is still going strong in late November - is only the 12th largest on record.

https://youtu.be/2tpvU46-CFs

This year's large hole is in contrast to last year's, which was the smallest on record, covering a mere 16.4 million square kilometres…

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Returning the mysterious parasitic flowering plant Dactylanthus or pua o te reinga to Zealandia sanctuary, in Wellington.

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Iwi representatives & conservationists journey to Zealandia sanctuary to plant seeds of the mysterious parasitic flowering plant Dactylanthus or flower of the underworld.

Seeds from one of New Zealand's most mysterious plants have been planted in central Wellington - but it'll be at least five years before it's known if the translocation has been successful.

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Te Pua o te Rēinga, or flower of the underworld, is New Zealand's only fully parasitic flowering plant. It parasitises the roots of trees such as five-finger and lives underground until it flowers, when its nectar-laden flowers push through to the forest floor.

Also known as waewae Atua, the toes or fingers of the Gods, and Dactylanthus taylori, pua o te Rēinga is naturally pollinated by pekapeka, short-tailed bats.

Natural populations of pua o te Rēinga have disappeared from the Wellington region, but efforts are being made to return the species to its former range.

The translocation involves, for the first time in a conservation project, all six iwi from across the Greater Wellington region: Rangitāne, Ngāti Kahungunu, Taranaki Whānui, Ngāti Toa Rangatira, Te Āti Awa ki Whakarongotai and Raukawa.

Holden Hohaia is one of the local iwi, te hau kāinga, with affiliations to Te Āti Awa and Taranaki Whānui

"It brings all together all our iwi, all our whanaunga on our eastern and western side, and gets us working on a kaupapa together," says Holden. "Te pua o te Rēinga actually unites us in a shared kaitiaki responsibility, so that's awesome."

The translocation took place in October 2020.

A group of iwi representatives and conservation staff from Wellington City Council and Zealandia Te Māra a Tāne ecosanctuary went to Pureora Forest to meet the iwi kāinga (Ngāti Rereahu and Ngāti Maniopoto) and collect kākano or seeds.

Hundreds of seeds were then planted at several sites at Otari-Wilton's Bush and Zealandia.

Sharlene Maoate-Davis (Ngati Toa Rangatira, Ngati Wehiwehi, Ngati Huia, Taranaki tuturu, Te Atiawa) says "it's a new love affair that's developed here with te pua o te Rēinga."

She says that a lot of Wellington iwi trace their ancestry back to Taranaki, where there are still natural populations of the plant.

"So kind of reconnecting all the dots together, that's what I think it's doing," says Sharlene.

We won't know for at least five years whether the seeds have successfully germinated and formed an attachment to a suitable tree root…

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The invention of a woven bassinet to save babies' lives & a geneticist seeking to understand plants & animals have won awards at the 2020 Research Honours Aotearoa.

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