Ocean Mercier’s journey from physics to the science of her ancestors.
Feijoas have become a New Zealand emblem. So how did they end up in Aotearoa, and how did we end up adoring them—to the point of obsession, for some—when feijoas have not really caught on anywhere else?
While normal earthquakes release energy suddenly and catastrophically, the slow-motion variety can last from days to months, can’t be felt by humans, and cause no damage. Slow-slip earthquakes were discovered around 20 years ago, and scientists are still trying to figure out what causes them. New Zealand’s Hikurangi Subduction Zone, off the east coast of the North Island, has become a global hotspot for the study of slow-slip quakes, because they happen at shallower depths than they do elsewhere, and so are easier to measure. The Hikurangi Subduction Zone is where the Pacific Plate is being shoved underneath the North Island, which lies on the edge of the Australian Plate. Off the coast of Wellington and the Wairarapa, the seabed is covered in sediment washed off the Southern Alps. That gives the Pacific Plate a nice, smooth surface, and as it’s pushed underneath the Australian Plate, the two plates tend to lock tightly together. (Every 500 years or so, this breaks in a giant megathrust earthquake of magnitude 8 or 9.) North of Hawke’s Bay, it’s a different story. There’s less sediment, so ancient undersea volcanoes called seamounts stick up out of the Pacific Plate, giving it a bumpy surface. That causes all kinds of strange behaviour as it’s sucked beneath the Australian Plate. GNS Science geophysicist Susan Ellis and her colleagues used a sophisticated computer model to simulate what happens when a seamount is pulled into the subduction zone. “The ground ahead becomes brittle and prone to earthquakes because the water is squeezed out,” says Ellis. As the seamount inches forward, it drags the seabed with it, stretching apart the rocks behind it and allowing fluids to fill tiny gaps in the rock. That weakens the rocks and makes slow-slip earthquakes possible. Researchers are trying to figure out what this means for New Zealand. How much of the stress built up along the fault will be released in slow-slip events? What will happen when the southern part of the Hikurangi Thrust eventually ruptures in “the big one”—something that hasn’t happened in recorded history?
You’ve hurt yourself in the mountains, and you’ll never make it out on your own. What happens next?
The once abundant Hauraki Gulf is on the brink of collapse, and while science is clear on how to repair it, many are putting rights before responsibilities. Here’s what needs to happen.
In the wake of Australia’s catastrophic bushfire season, the country’s forests face yet another pressure: logging. While it may seem reasonable to salvage timber from ravaged eucalypts, evidence suggests otherwise. Semi-burned trees and scorched logs are crucial to ecosystem recovery, offering shelter and food to surviving wildlife. “Many trees that look dead will still be alive. In the months ahead, buds will sprout from under the blackened bark,” says David Lindenmayer, a professor at the Australian National University. Already, a peppering of rain across the Blue Mountains has seen tiny buds of new growth appear after bushfires razed millions of hectares across the UNESCO World Heritage Area and multiple national parks. Following the deadly Black Saturday fires in 2009, post-fire logging in Victorian forests destroyed emerging seedlings and removed tree hollows, which are important for endangered species such as the Leadbeater’s possum and red-tailed black cockatoo. A 2016 study found that tree fern numbers plummet by 94 per cent after post-fire logging, while another study found that soils fail to regain their nutrients and fungal communities even 80 years after fire and logging. Fire risk also increases in areas that have been logged after fires. “At a time when habitat is so scarce,” says Lindenmayer, “practices like burning or mulching remaining timber, salvage logging and mop-up burning rob landscapes of the features that wildlife will need to recover.”
As some humans ponder their own extinction, others are figuring out the best places to run when the bomb drops, or the power goes off, or the supermarkets shut their doors. In a study published in the journal Risk Analysis, researchers Matt Boyd and Nick Wilson rated the appeal of the world’s islands as sanctuaries from a catastrophe such as a global pandemic. “The results indicate that the most suitable island nations for refuge status are Australia, followed closely by New Zealand, and then Iceland, with other nations all well behind,” they concluded. In particular, they considered subnational islands, such as Australia’s Tasmania, Japan’s Hokkaido, and New Zealand’s South Island. “Nevertheless, some key contextual factors remain relatively unexplored,” they cautioned, such as the willingness of those islands to accept refugees. And would we have enough cheese rolls for everyone?
Like bubbles in a pot of boiling water, this solar close-up shows convection cells on the sun’s surface. Hot plasma (bright white) rises from the sun’s interior, then cools and sinks (dark outlines). Each convection cell is around 2.5 times the size of New Zealand. It was photographed from a new solar observatory, the Daniel K. Inouye Solar Telescope (DKIST), which looks sunward from the summit of Haleakalā (literally ‘the house of the sun’), a 3000-metre peak in Hawai’i. The facility has a four-metre-wide mirror to resolve our nearest star in intimate detail. Features as small as 30 kilometres across can now be photographed. Looking directly at a burning ball of gas is tricky. Sunlight focused by the telescope generates enough heat to melt metal so, to keep the telescope cool, the facility makes a swimming pool’s worth of ice every night, then distributes it via more than 10 kilometres of piping. Why are we looking so closely at our star? Although the sun is nearly 150 million kilometres away, its weather can cause chaos on Earth. Solar flares and storms emit streams of charged particles that interfere with satellites and power supplies. By zooming in, astronomers hope to understand the magnetic processes behind such phenomena.
Three years ago, our most active volcano warned us of its impulsive and devastating power. We didn’t listen.
We've failed the Hauraki Gulf. Here's why.
When an undulating curve lit up the night sky above a group of Finnish aurora hunters, they flipped through their guidebook to identify it—but the aurora didn’t look like any of the 30 distinct forms pictured within. So the northern lights enthusiasts turned their cameras skyward, capturing the strange shape, which they called “the dunes”. “They told me I had excluded one aurora form from the book,” says Minna Palmroth, a space physicist at the University of Helsinki and author of the guide. Most aurora appear as shimmering green or pink curtains, stretched vertically. But the dunes were horizontal, like fingers of light reaching hundreds of kilometres towards the equator. Researchers from the University of Helsinki, including Palmroth, joined forces with the citizen skywatchers to document the new form, and their findings were reported in AGU Advances in January. Using the aurora hunters’ photos, scientists calculated the altitude of the dunes to be 100 kilometres above sea level. This suggests that the dunes are a visible manifestation of atmospheric waves—specifically, mesospheric bores, a type of wave that behaves like a ripple on the surface of a pond. “For the first time, we can actually observe atmospheric waves through the aurora. This is something that hasn’t been done before,” says Palmroth. Studying the dunes may help scientists understand the dynamics and interactions of Earth’s atmosphere in more detail. The new discovery echoes that of strong thermal emission velocity enhancement, or STEVE, a purple-green sky-glow phenomenon first documented by aurora seekers in Canada in 2016. Subsequent observations have confirmed that STEVE occurs in New Zealand skies—while photos captured by aurora seekers down under suggest that the dunes may also be part of the southern lights spectacle.
Poachers are raiding fragile caves to make a quick buck flogging moa bones to the highest bidder. Is it right?
What would happen if city suburbs as well as offshore islands enjoyed freedom from introduced predators? Is it possible for New Zealand to eliminate them all—stoats, ferrets, weasels, possums, and three species of rat?
Tibet is the rooftop of the world; the highest plateau on earth and an extreme high altitude environment where people have lived for five thousand years. Tibet is a place of ancient wonder and devoted spirituality but here an emerging modernity is now being woven into the tapestry of the region. These mystical people who live so close to heaven are beginning to open up and share their secrets.
Over thousands of years, the natural barriers in China’s remote south-western frontier have created isolated pockets of culture, incubating some of the world’s most extraordinary ways of life. 25 distinct ethnicities live in the province of Yunnan – from the buffalo-worshipping Wa to the water-splashing Dai. As modern development sweeps through the land, ancient secrets are shared with the world.
In the cold, steep world of the fiords, tannins block out sunlight to the world below. The fiords are cold and inhospitable in winter, when they receive little light and freeze over at their extremes. In this unforgiving world there are no second chances
In the Bay of Plenty, New Zealand’s most active volcano fills the sky with plumes of white cloud. Sterile and inhospitable, the forces that built White Island influence the seas around it.
Alone in the Pacific, halfway to Tonga, sit the Kermadec Islands. This remote archipelago is New Zealand’s northernmost frontier and our toehold on the tropics. Everything that lives on and around these young islands has travelled far to be here and a unique mix of creatures thrive in its warm waters. As a marine community the Kermadec is unrivalled in New Zealand waters.
Once at the crossroads of East and West on the ancient Silk Road, the vast expanse of Xinjiang is set to take a pivotal role again as China builds 21st century trade routes to take its goods to the world. In this culturally rich and climatically harsh region, the potential for growth appears as endless as the landscape. Xinjiang’s people may be ethnically diverse but they all share the steely determination required to survive and succeed in one of the most extreme environments on the planet.
From the Pacific Ocean to the Caribbean Sea Mexico is one of the most ecologically rich places anywhere. It draws wild travellers from afar to hunt, breed, rest and survive. At this crossroads life is never easy but there are jewels to be found. The cool blue waters in the west harbour giants, while smaller animals crisscross the nearby desert. In the jungles to the east an unseen multitude celebrate life while the moon shines.
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