THERE IS A SUCKER BORN EVERY MINUTE

Tutoring kids who don't need it is a booming business in affluent areas

by Pawan Dhingra, The Conversation

Many families shell out $200 monthly on private ‘learning centers.’ Credit: Beanosity, CC BY-SA

Many relatively well-off parents drive their kids to special activities after school. On top of trips to soccer practices and games or piano lessons and recitals, they increasingly make one more stop: a trip to their local after-school tutoring center.

In most cases these children don't attend underfunded schools or need help competing with those in affluent districts. Nor are they high school students looking to boost their SAT or ACT scores before applying to college. They are typically doing just fine at their schools or are ahead of their classmates. And yet they get private, long-term tutoring on a regular basis.

I've been researching this intensive after-school tutoring, which I call "hyper education," for eight years. It's becoming a more common extracurricular activity for children of all ages.

Even if public schools provided the same quality of education for all, which is demonstrably not the case, I fear that this trend is increasing the advantages that the children of affluent families already have over their peers.

Tutoring franchises

Tutoring, of course, has long been commonplace within and outside of American schools to help kids who are struggling to keep up in class. While for-profit tutoring businesses have been in the United States for decades, they have grown over the past two decades in urban and suburban communities alike.

Franchised chains of after-school learning centers, such as Kumon, Sylvan, Kaplan and Mathnasium, operate in over 50 countries. Parents pay these multinational corporations around US$200 per month for each child to get math, reading and other kinds of lessons once or twice a week with their own curriculum and homework assignments intended to be more challenging than what is offered by the schools.

While researching for my book "Hyper Education: Why Good Schools, Good Grades, and Good Behavior Are Not Enough," I interviewed more than 100 Asian American and white families with children in elementary or middle school whose kids go to after-school tutoring centers or participate in academic competitions, or do both.

Most live in Boston suburbs, but some reside elsewhere in the United States. Nearly all of these children attend high-performing public schools. I also spent time in after-school learning franchises and interviewed around 30 educators inside and outside the public school system.

Traffic patterns

No longer reserved for Manhattan families angling to get their toddlers and preschoolers into elite kindergartens, more and more families from a wide array of backgrounds enroll their kids in tutoring centers. While there is no hard data yet available regarding exactly how many children are getting this type of instruction, I believe it is safe to say the number is growing as parents with disposable income spend increasing amounts of money on their children to give them ever more advantages.

These educational franchises advertise as serving students not only struggling in academics but also those who are "already ahead in math."

Business is booming for Kumon, which has seen its revenue grow 60% in the past decade. Mathnasium, one of its top competitors, is one of North America's fastest-growing franchises.

A mother of children attending public schools in the Boston suburbs observed that one tutoring center is so popular that the town "had to change traffic patterns" to accommodate during drop-off and pickup times.

One center director told me that her growth plan was to open in areas that already have highly ranked school districts, since those families have shown a commitment to education and have the means to pay for more. Another director targeted his advertising efforts to families making at least $125,000 a year in his affluent Boston suburb.

No child is too young to start, it seems. Junior Kumon targets children starting at age three. They teach these little kids how to recognize letters, numbers, patterns and shapes. I even saw a child in diapers who was enrolled at a Kumon center.

Getting further ahead

Parents are keeping their kids enrolled in nonremedial tutoring for years if they feel like it's getting results.

"We just kind of kept her in the program, because it was working," the mother of a fifth grader told me. "It seemed like the public school math program just wasn't anywhere near stretching her capability to do math. So, it felt, like let's keep doing this."

Children enrolled in after-school academics can get confused about which kind of learning matters more. For instance, a fourth-grade student mentioned that her regular teacher counted her private math center assignments as satisfying her school homework. That raises good questions about which curriculum was more relevant and conducive to her learning.

Despite this industry's growth and what parents may believe, the effects of tutoring generally are mixed.

Troublingly, educators believe that the growth of private tutoring is contributing to a sense of academic pressure that can contribute to emotional problems, even for kids who aren't getting this extra instruction. The students who take classes outside of school "make other kids feel bad, because they're brighter, more capable, and they do more, and they can do it faster," a Boston-area elementary school principal told me.

As a result, I'm seeing a growing education arms race, of families feeling pressured to ensure their kids learn enough to be above their grade level and ranked at or near the top of their classes. This is starting at younger and younger ages. Many parents told me they enroll their elementary school children in hyper education simply to "keep up" with those who do.

In 2016, Mathnasium teamed up with the National Parent Teachers Association to help boost student performance in mathematics by hosting math games inside and outside of schools—a step that further embeds for-profit businesses into the public schools. Hyper education is growing. And as it does, it's seriously changing what it means to go to school and be a child.

Parents say their children have tutors to fill gaps, not to charge ahead

It's OK to feed wild birds: Here are some tips for doing it the right way

by Julian Avery, The Conversation

Costa’s Hummingbirds are frequent visitors at feeders in Arizona and southern California. Credit: Julian Avery, CC BY-ND

Millions of Americans enjoy feeding and watching backyard birds. Many people make a point of putting food out in winter, when birds needs extra energy, and spring, when many species build nests and raise young.

As a wildlife ecologist and a birder, I know it's important to understand how humans influence bird populations, whether feeding poses risks to wild birds, and how to engage with birds in sustainable ways.

There is still much to learn about the risks and benefits of feeding birds, particularly through large integrated national citizen science networks like Project FeederWatch. But we now have enough information to promote healthy interactions that can inspire future generations to care about conservation.

A long-term relationship

Birds have been taking advantage of human civilization for thousands of years, congregating where grains and waste are abundant. This means that people have been influencing the abundance and distribution of species for a very long time.

Studies show that providing food has myriad effects on birds' decisions, behaviors and reproduction. One significant finding is that winter bird feeding increases individual survival rates, can encourage birds to lay eggs earlier in the year, and can also improve nestling survival.

All of these factors alter species' future reproductive performance and can increase total bird abundance in later years. It's not always clear how increased abundance of feeder birds impacts other species through competition, but rarer and smaller species can be excluded.

Supplemental food has also led to reduced reproductive success in a few species. This may happen because it improves survival odds for less healthy birds that otherwise would be unlikely to survive and reproduce, or because it leads birds to eat fewer types of natural foods, making their diets less nourishing.

Data from Project FeederWatch show Northern Cardinal populations expanding into the upper Midwest, northern New England, the Southwest and southeastern Canada. Credit: Virginia Greene/Cornell Lab of Ornithology, CC BY-ND

Changing bird behavior

Research also shows that birds are extremely promiscuous. One review examined 342 species and found that in approximately 75%, birds had one or more side partners in addition to their nest mate.

It's not always clear why birds cheat, but several studies have found that supplemental feeding can reduce the amount of infidelity in certain species, including house sparrows. This hints that feeding birds might alter their behavior and have an effect on genetic variation in urban populations.

For birds that provide pollinating services, like hummingbirds and lorikeets, there is some evidence that providing them with sugar water—which mimics the nectar they collect from plants—can reduce their visits to native plants. This means they will transfer less pollen. Since much bird feeding happens in densely populated urban areas, it's unclear how much impact this might have.

Some bird populations depend completely on feeding and would collapse over the winter without it. For example, Anna's hummingbirds in British Columbia rely on heated feeders. Other species, such as hummingbirds in the southwest U.S., have become more locally abundant. Northern cardinals and American goldfinches have shifted and expanded their ranges northward with the availability of food.

In one incredible instance, garden feeders seem to have played a role in establishing a new wintering population of migratory blackcaps in the United Kingdom. This group is now genetically distinct from the rest of the population, which migrates further south to Mediterranean wintering grounds.

The band on this black-capped chickadee’s right leg assigns the bird a unique number. Scientists band birds to study their ranges, migration, life spans and other questions. The feeder holds suet, a high-energy food made from animal fat. Credit: Julian Avery, CC BY-ND

Don't feed the predators

Scientists still know little about how bird feeding affects transmission of pathogens and parasites among birds. It is not uncommon for birds at feeders to carry more pathogens than populations away from feeders. Some well-documented outbreaks in the U.S. and U.K. have shown that feeding birds can increase problems associated with disease—evidence that was collected through feeder watch citizen science projects.

Because we still have a poor understanding of pathogen transmission and prevalence in urban areas, it is extremely important to follow hygiene guidelines for feeding and be alert for new recommendations.

Feeding can also attract predators. Domestic cats kill an estimated 1.3 to 4 billion birds in the U.S. every year. Feeders should not be placed in settings where cats are present, and pet cats should be kept indoors.

Feeders can also support both native and introduced birds that outcompete local species. One study found that feeders attracted high numbers of crows, which prey on other birds' chicks, with the result that less than 1% of nearby American robin nests fledged young. In New Zealand, bird feeding largely benefits seed-eating introduced species at the expense of native birds.

Clean feeders and diverse diets

The good news is that studies do not show birds becoming dependent on supplemental food. Once started, though, it is important to maintain a steady food supply during harsh weather.

Treatments on this window at Shaver’s Creek Environmental Center prevent birds from thinking they can fly straight through the building and colliding with the glass. Credit: Julian Avery, CC BY-ND

Birds also need access to native plants, which provide them with habitat, food and insect prey that can both supplement diets and support species that don't eat seeds at feeders. Diverse food resources can counteract some of the negative findings I've mentioned related to competition between species and impacts on bird diets.

Good maintenance, placement and cleaning can help minimize the likelihood of promoting pathogens at feeders. Initiatives like Project FeederWatch have recommendations about feeder design and practices to avoid. For example, platform feeders, where birds wade through the food, are associated with higher mortality, possibly through mixing of waste and food.

It's also important to manage the area around feeders. Be sure to place feeders in ways that minimize the likelihood that birds will fly into windows. For instance, avoid providing a sight line through a house, which birds may perceive as a corridor, and break up window reflections with decals.

There are lots of great reasons to bring birds into your life. Evidence is growing that interacting with nature is good for our mental health and builds public support for conserving plants and wildlife. In my view, these benefits outweigh many of the potential negatives of bird feeding. And if you get involved in a citizen science project, you can help scientists track the health and behavior of your wild guests.

When managing birdfeeders, think bird health and safety

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Provided by The Conversation 

Intelligently recovering and recycling balsa wood

by Fraunhofer-Gesellschaft MARCH 2, 2020

Around 20 percent of electricity in Germany was generated by wind turbines in 2018. Credit: Hans-Peter Merten/MATOfoto

There are 30,000 wind turbines in operation in Germany, many of which are starting to age. In 2019, 2000 rotor blades had to be discarded; in 2024, this figure will shoot up to 15,000. But where to put these up to 90-meter-long, 15-metric-ton behemoths? Researchers from the Fraunhofer Institute for Wood Research, Wilhelm-Klauditz-Institut, WKI have a solution: they used a new recycling technique to recover and process the balsa wood contained in the rotor blades into, for instance, insulation mats for buildings.


Old wind power generators have to be disposed of—whether due to material fatigue or simply because they are being replaced by larger and more efficient systems. A study by the Fraunhofer Institute for Chemical Technology ICT predicts that the 15,000 rotor blades that will have to be discarded in 2024 will be joined by another 72,000 in the subsequent three years. We already have environmentally friendly methods for disposing of the steel and concrete in the wind power generators, but recycling the rotor blades remains problematic.

Firmly bonded and nearly impossible to separate

Rotor blades are not made of steel. "That would be too heavy and inflexible. They are made largely of glass-fiber-reinforced plastic (GFRP) and balsa wood bonded with epoxy or polyester resin," says Peter Meinlschmidt, project manager at the Fraunhofer Institute for Wood Research, Wilhelm-Klauditz-Institut, WKI in Braunschweig. This bond is extremely strong. It has to be: the rotor blades reach top speeds of more than 250 kilometers per hour, subjecting them to an enormous force. For single-origin recycling, however, this is precisely the problem, as it is very difficult to separate the individual components of the composite material.

A rotor blade contains around 15 cubic meters of balsa wood, which is not only one of the world's lightest woods, but also extremely resistant to pressure. "That's the key advantage of balsa over most plastic foams," explains Meinlschmidt. Previously, there was no possibility to recover it when disposing of the old rotor blades. "Although it has hardly any energy content, it is burned as a composite material, usually in cement factories. The cement raw materials have to be heated up to about 1500 degrees Celsius before they coalesce and form cement clinker, so these factories require a great deal of energy. In addition, the melted glass fibers and the ash can later be added to the cement and replace portions of the quartz sand that would otherwise have to be input into the process." But the number of cement plants in Germany is limited (there are 53 in total), and so is their need for rotor blades as combustion material.


Disassembling rotor blades with a water jet lance

But there is still hope for getting the impending flood of rotor blades under control: Meinlschmidt and his team—Fraunhofer ICT colleagues and industry partners—have developed a new recycling technology. To recover and recycle the balsa from the rotor blades, the detached blades are disassembled on the spot. "The conventional approach is to use a band saw to cut the rotor blades into thirds or quarters, but this is a relatively complex process. That's why we came up with the idea to try it with a water jet lance instead. And what do you know: it was much faster and better," says an enthusiastic Meinlschmidt. The lance can be mounted on a special vehicle and controlled from there. "The tremendous thrust would make it extremely difficult to guide the lance by hand." Then, while still on site, the 10- to 20-meter-long rotor blade segments are fed into a mobile shredder that breaks them into pieces about the size of the palm of a hand.

Finally, the research team uses an impact mill to separate these pieces into their individual components. To this end, they are set in rotation and hurled against metal at high speed. As Meinlschmidt explains, "The composite material then breaks apart because the wood is viscoplastic, while glass fibers and resin are very hard."

Insulating with rotor blades

At Fraunhofer WKI, the balsa pieces are processed to make, for instance, ultra-light-weight wood-fiber insulation mats. "Currently around 10 percent of building insulation materials are made from renewable resources—there's room for improvement here." With a density of less than 20 kilograms per cubic meter, these mats are so far unique on the market and provide similarly good insulation to common polystyrene-based materials.

The recycled balsa can also be used to produce a novel, elastic wood foam. For this, it is ground to a very fine powder and combined with a foaming agent. The foam's stability is created by the wood's own cohesive forces, which render synthetic adhesives superfluous. The foam is suitable for use as an environmentally friendly insulating material, but also as a packaging material that can simply be disposed of in the paper recycling container.


Explore furtherLightweight rotor blades made from plastic foams for offshore wind turbines

Provided by Fraunhofer-Gesellschaft

Weaving insect wildlife back into the tapestry of life

by Michael Samways, The Conversation

Credit: CC0 Public Domain

Insects are fundamental to the functioning of land and freshwater ecosystems. They permeate all aspects of these ecosystems, chewing and pooing, pollinating, seed spreading and affecting each other's population levels through predation and parasitism. They also provide ecological processes of vital importance for frogs, lizards, birds and mammals, especially as food items for these vertebrates.

Insects also supply ecosystem services of great benefit in support of human activity, especially food and fibre production, through actions such as pollination, nutrient cycling and control of pest insects. This means that the fate of insects is entwined with that of people and of many other vertebrates.

Yet all is not well with this entomological fabric. Insects are declining in abundance in many parts of the world, and species are being lost at a rapid rate, especially through the felling of tropical trees.

Scientists warn that these declines and losses are undermining the ecosystems on which many lives depend. One of the known root causes is habitat loss. This occurs especially through insect population decline and extinctions arising from the carving up of the landscape and planting extensive fields of single crops which causes landscape degradation and eventually leads to loss of their natural habitat.

Other factors are the uncontrolled use of polluting compounds, especially nitrogen-based fertilisers, overuse of pesticides, the spread of invasive alien species and loss because other species on which they depend are also being lost.

Overarching all of these impacts is global climate change, which is complex in its manifestation on insect populations and interacts with the other impacts. Climate change is associated with more extreme weather events and with more intense and frequent fires reducing insect populations. It also changes pest prevalence, making their control more difficult.

In addition to this, landscape fragmentation and habitat loss mean that insects cannot move so easily across the terrain to find the conditions that suit them best, as they once did. And these optimal habitats are becoming further apart and smaller. Yet the future is not at all hopeless. Strategies are being put in place in various parts of the world that when scaled up, will benefit insects globally.

Unequal effect

Not all insects are being affected equally. Individual species responses depend on genetic disposition, crafted by past events, often long before human impact on the landscape.

Some species survive well in human-modified circumstances, whether agro-forestry or in cities. Others have the capability of surviving well in certain agro-ecosystems or even city parks. But many are specialists that require particular circumstances or particular host species in order to live.

These specialists are the ones being lost at an alarming rate, especially in tropical forests undergoing rampant deforestation. Their home space is being greatly reduced, lessening their opportunity for survival. When this shrinking space reaches a critically low level, they have nowhere else to go.

In contrast, some genetic modifications enable certain insects to adapt to the changing human environment. The Small ermine moth (Yponomeuta cagnagella), for example, is becoming less responsive to artificial light, improving its chances of survival in the urban environment.

Others can benefit enormously from some artificial environments. This is best seen in the case of artificial ponds. Our research found that these provide many more opportunities for survival, as more options are available, especially when natural ponds are under drought stress.

What needs to be done

International scientists have proposed a roadmap to deal with many of the problems that insects are facing. These are strategies for a way forward not only for long-term insect survival but for ensuring that insect populations continue to provide ecosystem services beneficial to humans. These include the pollination of crops, control of pests using natural predatory and parasitic insects and maintenance of healthy soil.

Recently though, much more detailed strategies have emerged. These focus on specific ecosystems, whether forest, grassland, freshwater, caves or cities. In short, various research activities around the world, in concert with effective implementation, have illustrated that there are positive ways forward.

These strategies involve much more investment in the future, rather than on destructive short-term economic gains. Different parts of the world can benefit from these findings and tailor them to local conditions.

Among the strategies available are implementation of functional corridor networks of natural vegetation among crops and plantations that enable insects to move across the landscape. Planting particular vegetation between crop rows and around field margins can also be beneficial, as can the careful planting of roadsides.

Rivers can be rehabilitated by ensuring no run-off of pollutants and pesticides, and restoring the river banks with natural vegetation. Reduced insecticide input is essential, as pollinating bees in particular are suffering greatly.

Biological alternatives to pest control, such as parasitic wasps and predatory beetles, are available. These often go hand in hand with re-establishment of natural vegetation.

Cities, towns and abandoned land can also make a great contribution by increasing the amount of green space relative to the hard grey of the man-made structures. Vegetated green roofs and walls can also help create habitats for insects.

If this generation doesn't put these strategies in place, the future for future generations will be bleak because options for resilient landscapes are diminishing

Scientists warn humanity about worldwide insect decline

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Provided by The Conversation 

Fish school by randomly copying each other, rather than following the group

by University of New South Wales

A school of trevallies. Credit: Milos Prelevic on Unsplash.

Fish school by copying each other and changing directions randomly, rather than calculating and adapting to an average direction of the group, a group of scientists co-led by UNSW has shown.

In a study published today in Nature Physics, an international team from Australia, India and UK has shed light on the behavioural dynamics that govern alignment, or collective motion, of cichlid fish—offering new insights into the dynamics of schooling, and potentially the coordinated behaviour of other animals.

"In the fish that we have studied, schooling turns out to be noise-induced. It's not what anyone traditionally thought it was," says Dr. Richard Morris from UNSW Science, co-leader of the study and EMBL Australia group leader in UNSW's Single Molecule Science.

"Noise, in this setting, is simply the randomness arising from interactions between individual fish."

In the study, the researchers present the first experimental evidence of noise-induced ordering, which previously only existed as a theoretical possibility. The interdisciplinary team of ecologists, physicists and mathematicians achieved this by combining the capabilities of their scientific disciplines to integrate experiments with computer simulations and analysis.

"Everyone's been aware of noise-induced phenomena, theoretically, but it's quite rare to find in practice. You can only observe it when the individuals in a study can actually make decisions. For example, you wouldn't find this type of noise-induced behaviour studying electrons or particles," says Dr. Morris.

This new model proposed contradicts the standard 'moving average' theories for schooling and herding behaviour, which assume that the animals are capable of estimating the overall direction of the group.

"Every fish only interacts with one other fish at any given time. They either spontaneously change direction, or copy the direction of a different fish. Calculating an average direction of the group—which was the popular theory until now—is likely too complicated for a fish to compute," explains Dr. Morris.

To study the behavioural dynamics, the researchers filmed schools of 15, 30 and 60 cichlid fish, tracking their trajectories to analyse the mechanism behind mutual alignment, or schooling.

"Smaller groups of fish schooled more coherently than large groups. This is counterintuitive, since the randomness, or noise, from individual interactions plays a bigger role in smaller groups than larger ones," Dr. Morris says.

When researchers interpret data, noise is usually an unrelated factor that obscures and distracts from the information, like glare from the sun that you would try to eliminate to get a clearer photo.

In this case, Dr. Morris explains that the random copying between pairs of fish gives rise to a different class of noise, and is actually what drives their highly coordinated behaviour. This new insight highlights the importance of noise, showing that noise may encode some important information about behavioural dynamics of fish and other animals.

"Here the signal is the noise. If you ignored the fluctuations completely, you couldn't explain schooling at all."

Beyond fish behaviour, the discovery has the power to reshape the understanding of collective motion in animals, and calls for a revision of how noise is treated in studies of behaviour dynamics.

Noise pollution found to be disruptive for schooling fish

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More information: Noise-induced schooling of fish, Nature Physics (2020). DOI: 10.1038/s41567-020-0787-y , https://nature.com/articles/s41567-020-0787-y

Sinking sea mountains make and muffle earthquakes

by University of Texas at Austin

T?ranganui Knoll is an underwater mountain (seamount) off the coast of New Zealand that was the site of an International Ocean Discovery Program drilling expedition. The seamount will one day collide with the Hikurangi subduction zone, leading to conditions that both generate and dampen earthquakes. Credit: Andrew Gase/National Institute of Water and Atmospheric Research

Subduction zones—places where one tectonic plate dives beneath another—are where the world's largest and most damaging earthquakes occur. A new study has found that when underwater mountains—also known as seamounts—are pulled into subduction zones, not only do they set the stage for these powerful quakes, but also create conditions that end up dampening them.

The findings mean that scientists should more carefully monitor particular areas around a subducting seamount, researchers said. The practice could help scientists better understand and predict where future earthquakes are most likely to occur.

"The Earth ahead of the subducting seamount becomes brittle, favoring powerful earthquakes while the material behind it remains soft and weak, allowing stress to be released more gently," said co-author Demian Saffer, director of the University of Texas Institute for Geophysics (UTIG), a research unit of The University of Texas at Austin Jackson School of Geosciences.

The study was published on March 2 in Nature Geoscience and was led by Tian Sun, who is currently a research scientist at the Geological Survey of Canada. Other co-authors include Susan Ellis, a scientist at the New Zealand research institute GNS Science. Saffer supervised the project and was Sun's postdoctoral advisor at Penn State when they began the study.

The researchers used a computer model to simulate what happens when seamounts enter ocean trenches created by subduction zones. According to the model, when a seamount sinks into a trench, the ground ahead of it becomes brittle, as its slow advance squeezes out water and compacts the Earth. But in its wake, the seamount leaves a trail of softer wet sediment. The hard, brittle rock can be a source for powerful earthquakes, as forces generated by the subducting plate build up in it—but the weakened, wet material behind the seamount creates an opposite, dampening effect on these quakes and tremors.

The researchers integrated data from samples of subducting rock and sediment around seamounts, like these cores which were drilled from offshore Japan in 2000. The cores contain a mixture of rock, sediments and water and give researchers insight into what happens as a seamount is ground between tectonic plates. Credit: Demian Saffer

Although seamounts are found all over the ocean floor, the extraordinary depths at which subduction occurs means that studying or imaging a subducting seamount is extremely difficult. This is why until now, scientists were not sure whether seamounts could affect the style and magnitude of subduction zone earthquakes.

The current research tackled the problem by creating a realistic computer simulation of a subducting seamount and measuring the effects on the surrounding rock and sediment, including the complex interactions between stresses in the Earth and fluid pressure in the surrounding material. Getting realistic data for the model involved conducting experiments on rock samples collected from subduction zones by scientific ocean drilling offshore Japan.

The scientists said the model's results took them completely by surprise. They had expected water pressure and stress to break up material at the head of the seamount and thus weaken the rocks, not strengthen them.

"The seamount creates a feedback loop in the way fluids get squeezed out and the mechanical response of the rock to changes fluid pressure," said Ellis, who co-developed the numerical code at the heart of the study.

The scientists are satisfied their model is robust because the earthquake behavior it predicts consistently matches the behavior of real earthquakes.

Scientific ocean drilling from research vessels such as the JOIDES Resolution provides a key source of data about what happens when an underwater mountain collides with a subduction zone. Credit: Joshua Mountjoy

While the weakened rock left in the wake of seamounts may dampen large earthquakes, the researchers believe that it could be an important factor in a type of earthquake known as a slow slip event. These slow-motion quakes are unique because they can take days, weeks and even months to unfold.

Laura Wallace, a research scientist at UTIG and GNS Science, who was the first to document New Zealand slow slip events, said that the research was a demonstration of how geological structures in the Earth's crust, such as seamounts, could influence a whole spectrum of seismic activity.

"The predictions from the model agree very nicely with what we are seeing in New Zealand in terms of where small earthquakes and tremors are happening relative to the seamount," said Wallace, who was not part of the current study.

Sun believes that their investigations have helped address a knowledge gap about seamounts, but that research will benefit from more measurements.

"We still need high resolution geophysical imaging and offshore earthquake monitoring to better understand patterns of seismic activity," said Sun.

Earthquake triggers 'slow motion' quakes in New Zealand

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More information: Mechanical and hydrological effects of seamount subduction on megathrust stress and slip, Nature Geoscience (2020). DOI: 10.1038/s41561-020-0542-0 , https://nature.com/articles/s41561-020-0542-0

Journal information: Nature Geoscience 

Early Earth may have been a 'waterworld'

by University of Colorado at Boulder

Benjamin Johnson inspects an outcrop in the Panorama district by what was once an ancient hydrothermal vent. Credit: Jana Meixnerova

Kevin Costner, eat your heart out. New research shows that the early Earth, home to some of our planet's first lifeforms, may have been a real-life "waterworld"— without a continent in sight.

The study, which appears March 2 in Nature Geoscience, takes advantage of a quirk of hydrothermal chemistry to suggest that the surface of Earth was likely covered by a global ocean 3.2 billion years ago. It may even have looked a bit like the post-apocalyptic, and land-free, future imagined in Costner's infamous film Waterworld.

The group's findings could help scientists to better understand how and where single-cell organisms first emerged on Earth, said Boswell Wing, a coauthor of the research.

"The history of life on Earth tracks available niches," said Wing, an associate professor in the Department of Geological Sciences at the University of Colorado Boulder. "If you've got a waterworld, a world covered by ocean, then dry niches are just not going to be available."

The study also feeds into an ongoing debate over what ancient Earth may have looked like: Was the planet much hotter than it is today?

"There was seemingly no way forward on that debate," said lead author Benjamin Johnson, who conducted the research during a postdoctoral position in Wing's lab at CU Boulder. "We thought that trying something different might be a good idea."

A crazy place

For him and Wing, that something different centered around a geologic site called the Panorama district located deep in Northwestern Australia's outback.

This pillow basalt lined the seafloor roughly 3.2 billion years ago. Credit: Benjamin Johnson

"Today, there are these really scrubby and rolling hills that are cut through by dry river beds," said Johnson, now an assistant professor at Iowa State University in Ames. "It's a crazy place."

It's also the resting spot for a 3.2 billion-year-old chunk of ocean crust that's been turned on its side.

In the span of a day at Panorama, you can walk across what used to be the hard, outer shell of the planet—all the way from the base of that crust to the spots where water once bubbled up through the seafloor via hydrothermal vents.

The researchers saw it as one-of-a-kind opportunity to pick up clues about the chemistry of ocean water from billions of years ago.

"There are no samples of really ancient ocean water lying around, but we do have rocks that interacted with that seawater and remembered that interaction," Johnson said.

The process, he explained, is like analyzing coffee grounds to gather information about the water that poured through it. To do that, the researchers analyzed data from more than 100 rock samples from across the dry terrain.

They were looking, in particular, for two different flavors—or "isotopes"—of oxygen trapped in stone: a slightly heavier atom called Oxygen-18 and a lighter one called Oxygen-16.

The duo discovered that the ratio of those two isotopes of oxygen may have been a bit off in seawater 3.2 billion years ago—with just a smidge more Oxygen-18 atoms than you'd see today.

"Though these mass differences seem small, they are super sensitive," Wing said.

A vista of the Panorama district looking down from the top of the ancient ocean crust to its base. Credit: Benjamin Johnson

Lost at sea

Sensitive, it turns out, to the presence of continents. Wing explained that today's land masses are covered by clay-rich soils that disproportionately take up heavier oxygen isotopes from the water—like mineral vacuums for Oxygen-18.

The team theorized that the most likely explanation for that excess Oxygen-18 in the ancient oceans was that there simply weren't any soil-rich continents around to suck the isotopes up. That doesn't mean, however, that there weren't any spots of dry land around.

"There's nothing in what we've done that says you can't have teeny, micro-continents sticking out of the oceans," Wing said. "We just don't think that there were global-scale formation of continental soils like we have today."

Which leaves a big question: When did plate tectonics push up the chunks of rock that would eventually become the continents we know and love?

Wing and Johnson aren't sure. But they're planning to scour other, younger rock formations at sites from Arizona to South Africa to see if they can spot when land masses first roared onto the scene.

"Trying to fill that gap is really important," Johnson said.

For now, Costner may want to start planning the prequel

Lost continents found deep underground as old as Earth shed light on planet's formation

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More information: Limited Archaean continental emergence reflected in an early Archaean 18O-enriched ocean, Nature Geoscience (2020). DOI: 10.1038/s41561-020-0538-9 , https://nature.com/articles/s41561-020-0538-9

RACIST JINGOISM

Trump administration to cap number of employees at Chinese media outlets in U.S

WASHINGTON (Reuters) - The United States on Monday said it was slashing the number of Chinese employees permitted to work at the U.S. offices of major Chinese state-owned media outlets to retaliate against Beijing over its “long-standing intimidation and harassment of journalists.”

Citing a “deepening crackdown” on all forms of independent reporting inside China, administration officials said Beijing’s attack on free speech was worse than it was a decade ago, comparing it to that of the Soviet Union at the height of the Cold War.

China last month revoked the visas of three Wall Street Journal reporters in Beijing after the newspaper declined to apologize for a column with a headline calling China the “real sick man of Asia”. Another reporter with the paper had to leave last year after China declined to renew his visa.

“For years, the government of the People’s Republic of China has imposed increasingly harsh surveillance, harassment, and intimidation against American and other foreign journalists operating in China,” U.S. Secretary of State Mike Pompeo said in a statement.

Effective March 13, Washington will be capping the number of U.S. based employees of Xinhua News Agency, China Global Television Network, China Radio International, China Daily Distribution Corp to a total of 100, from 160.

Monday’s decision was not particularly linked to the Wall Street Journal case, senior state Department officials, speaking on the condition of anonymity, told reporters.


“We’ve been imploring the Chinese for years and years now to improve their treatment of journalists in China. So, this is not linked to any one particular incident,” one U.S. official said, but added that the expulsion of Journal reporters was a “fairly egregious” example.

The four outlets were among five designated by the United States as foreign embassies earlier this month, as a first step of this move.

Tensions between the two superpowers have escalated since President Donald Trump came to office three years ago, with disputes over issues ranging from trade to accusations of Chinese spying in the United States and to U.S. support for Taiwan.

On Monday, the Foreign Correspondents Club of China said in a report that the Chinese government has “weaponized” visas as part of a stepped-up campaign of pressure on foreign journalists.

“It is our hope that this action will spur Beijing to adopt a more fair and reciprocal approach to U.S. and other foreign press in China,” Pompeo said, while State Department officials said Washington was ready to take further action if Beijing retaliated.

“If in fact they decide to take this in a further negative direction however of course..all options would be on the table. I can’t tell you what in particular we would do, but we’d sit down review the circumstances and then consider all of our options,” the official said.

The personnel caps would be placed on the entities as opposed to people hence it would be up to the media outlets to decide the necessary staffing cuts, the officials said.

While the United States will not be sending anyone back, the officials acknowledged that the Chinese individuals whose visas are contingent on their ability to work in the United States may be forced to leave the country.

The United States would also be announcing in near future limits on duration of stay for Chinese citizens, administration officials said.