Science & Environment

[CaaC (John)+]

Grace gravity mission captures Greenland ice loss

Greenland shed an extraordinary 600 billion tonnes of ice by the end of summer last year.

This melt-driven loss would have raised global sea levels by 2.2mm, say scientists who've just published an analysis of satellite gravity measurements taken over the Arctic.

Of course, when winter set in, some of that mass would have been recovered as it snowed across the ice sheet.

The data comes from the joint US-German space mission known as Grace-FO.

It's actually a pair of satellites that circle the globe, sensing the "lumps and bumps" in Earth's gravity field that correspond to variations in mass.

Key signals being detected are changes in the amount of water stored on land surfaces and the withering state of the planet's great ice fields.

FO stands for "follow on" because the project is a successor to a mission that flew from 2002 to 2017.

The analysis appearing in the journal Geophysical Research Letters (GRL) on Wednesday is essentially a first attempt to match up the new observational tool with the old.

It's a task that was made more challenging than it should have been, concede scientists.

In part that was because there was a seven-month gap in operations (Grace-FO wasn't launched until 2018), but also because the new mission, once in orbit, was found to be carrying an underperforming accelerometer instrument.

The team has had to find a work-around for this disappointment.

"But the exciting news is we are working and we are working well. And that's important because Grace gives us a really unique way of looking at the ice sheets and their glaciers," Prof Isabella Velicogna, from the University of California at Irvine and the US space agency's (Nasa) Jet Propulsion Laboratory, told BBC News.

 

• Greenland and Antarctica ice loss accelerating
• Grace mission launches to weigh Earth's water
• ICESat space laser makes height maps of Earth

Climate change: Greenland's ice faces melting 'death sentence'

Other types of satellite measure the ice sheets by capturing changes in velocity or shape. Grace, on the other hand, literally weighs the ice from orbit. It's, therefore, an independent check on those other satellites' methods.

The big take-home from the GRL paper is that the new gravity mission is capturing all major trends.

The Greenland melt of last summer would have been hard to miss. It was extreme. On a par with the very warm summer of 2012.

In the coastal town of Ilulissat, not far from where the mighty Jakobshavn Glacier enters the ocean, temperatures reached into the high 20s Celsius.

And even in the ice sheet's interior, at its highest point, temperatures got to about zero.

"It's significant that we're now seeing melt and mass loss extending to Greenland's northern glaciers. All of Greenland contributed to the big summer melt of last year," said Prof Velicogna.

Across the entire period of the two missions - 2002 to 2019 - Greenland has lost some 4,550 billion tonnes of ice, an average of 268 billion tonnes annually, which puts the scale of last summer into further context.

In Antarctica, for the full Grace period, the ice sheet is seen to be losing just over 100 billion tonnes every year. The match-up between the old and new gravity measurements is not quite as consistent as in Greenland, but this should improve with time, commented Prof Andrew Shepherd from Leeds University, UK.

"This is the first effort to cross-calibrate the missions which are really welcome because the Grace gravity data is important for our science. That's a massive positive. No-one expects a first paper, the first data from a mission, to be perfect; the processing of the data can only get better," he told BBC News.

https://www.bbc.co.uk/news/science-environment-51954988

 

 

[CaaC (John)+]

Diamond samples in Canada reveal the size of a lost continent

Canadian scientists have discovered a fragment of an ancient continent, suggesting that it was 10% larger than previously thought.

They were studying diamond samples from Baffin Island, a glacier-covered landmass near Greenland when they noticed a remnant of North Atlantic Craton.

Cratons are ancient, stable parts of the Earth's continental crust.

The North American Craton stretched from present-day Scotland to North America and broke apart 150m years ago.

Scientists chanced on the latest evidence as they examined exploration samples of kimberlite, a rock that often contains diamonds, from Baffin Island.

"For researchers, kimberlites are subterranean rockets that pick up passengers on their way to the surface," University of British Columbia geologist Maya Kopylova said. "The passengers are solid chunks of wall rocks that carry a wealth of details on conditions far beneath the surface of our planet over time."

Ms Kopylova and her colleagues says the sample bore a mineral signature that matched other portions of the North Atlantic Craton.

"Finding these 'lost' pieces is like finding a missing piece of a puzzle," Ms Kopylova is quoted as saying in an article published by the University of British Columbia's website.

The samples were taken from deep below the Chidliak Kimberlite Province in southern Baffin Island. Previous reconstructions of the Earth's plates had been based on shallow rock samples formed at depths of one to 10km (six miles).

Ms Kopylova said the discovery adds about 10% to the known size of the craton. "Our knowledge is literally and symbolically deeper," she said.

https://www.bbc.co.uk/news/world-us-canada-51989255

[CaaC (John)+]

Fossil worm shows us our evolutionary beginnings

A worm-like creature that burrowed on the seafloor more than 500 million years ago may be key to the evolution of much of the animal kingdom.

The organism, about the size of a grain of rice, is described as the earliest example yet found in the fossil record of a bilaterian.

These are animals that have a front and back, two symmetrical sides, and openings at either end joined by a gut.

The discovery is described in the journal PNAS.

The scientists behind it say the development of bilateral symmetry was a critical step in the evolution of animal life.

It gave organisms the ability to move purposefully and a common, yet successful way to organise their bodies.

A multitude of animals, from worms to insects to dinosaurs to humans, are organised around this same basic bilaterian body plan.

Scott Evans, of the University of California at Riverside, and colleagues have called the organism Ikaria wariootia.

• Mammal study explains 'why females live longer'
• Earth's deepest ice canyon vulnerable to melting
• Electric car emissions myth 'busted'

It lived 555 million years ago during what geologists term as the Ediacaran Period - the time in Earth history when life started to become multi-celled and much more complex.

The discovery started with tiny burrows being identified in rocks in Nilpena, South Australia, some 15 years ago.

Many who looked at these traces recognised they were likely made by bilaterians, but creatures' presence in the ancient deposits was not obvious.

It was only recently that Scott Evans and Mary Droser, a professor of geology at UC Riverside, noticed minuscule, oval impressions near some of the burrows.

Three-dimensional laser scanning revealed the regular, consistent shape of a cylindrical body with a distinct head and tail and faintly grooved musculature.

Ikaria wariootia ranged in size between 2mm and 7mm long, and about 1-2.5mm wide. The largest of the ovals was just the right size and shape to have made the long-recognised burrows.

"We thought these animals should have existed during this interval, but always understood they would be difficult to recognise," Scott Evans said. "Once we had the 3D scans, we knew that we had made an important discovery."

Ikaria wariootia probably spent its life burrowing through layers of sand on the ocean floor, looking for any organic matter on which it could feed.

https://www.bbc.co.uk/news/science-environment-52019468

 

Edited March 25, 2020 by CaaC (John)

[CaaC (John)+]

19 Everyday Things Science Hasn’t Figured Out

Science has enabled humans to complete some pretty incredible feats, like land on the moon, for example. But when it comes to common things like laughter or hiccups, scientists still can’t quite figure out the reason behind them. In this article, which was adapted from The List Show on YouTube, we look at everyday things that are still a mystery.

1. It's still not understood why we cry.

Crying is still a scientific mystery. Physiologically, it’s clear what’s happening when someone cries. But, it has been more difficult to figure out the evolutionary reason for tears. We know that babies cry to communicate and get attention. So, some experts believe that adults might also cry for social reasons, like to bond or to warn others that something is amiss.

2. The reason we laugh is still unknown.

Like crying, we also don’t know why people evolved the ability to laugh, but experts guess it has something to do with communication—and not just that we find something funny. One researcher found that only 20 per cent of laughs he looked at were preceded by anything deemed in any way humorous.

It's possible we laugh to let other people know that we’re okay or to bond with each other. A study published in 2016 gave evidence for the latter. Researchers found that an outside observer could distinguish whether laughter was produced between a pair of strangers or a pair of friends.

FULL REPORT

Edited April 4, 2020 by CaaC (John)
Add On

[CaaC (John)+]

Crops were cultivated in regions of the Amazon '10,000 years ago'

Far from being a pristine wilderness, some regions of the Amazon have been profoundly altered by humans dating back 10,000 years, say researchers.

An international team found that during this period, crops were being cultivated in a remote location in what is now northern Bolivia.

The scientists believe that the humans who lived here were planting squash, cassava and maize.

The inhabitants also created thousands of artificial islands in the forest.

• Coronavirus: 'Pets no risk to owners' vet's stress
• Some plants recover quickly after crushing blows
• Exploiting nature 'drives the outbreaks of new diseases'

The end of the last ice age, around 12,000 years ago, saw a sustained rise in global temperatures that initiated many changes around the world.

Perhaps the most important of these was that early civilisations began to move away from living as hunter-gatherers and started to cultivate crops for food.

Researchers have previously unearthed evidence that crops were domesticated at four important locations around the world.

So China saw the cultivation of rice, while in the Middle East it was grains, in Central America and Mexico it was maize, while potatoes and quinoa emerged in the Andes.

Now scientists say that the Llanos de Moxos region of southwestern Amazonia should be seen as a fifth key region.

The area is a savannah but is dotted with raised areas of land now covered with trees.

The area floods for part of the year but these "forest islands" remain above the waters.

Some 4,700 of these small mounds were developed by humans over time, in a very mundane way.

"These are just places where people dropped their rubbish, and over time they grow," said lead author Dr Umberto Lombardo from the University of Bern, Switzerland.

"Of course, rubbish is very rich in nutrients, and as these areas grow they rise above the level of the flood during the rainy season, so they become good places to settle with fertile soil, so people come back to the same places all the time."

The researchers examined some 30 of these islands for evidence of crop planting.

They discovered tiny fragments of silica called phytoliths, described as tiny pieces of glass that form inside the cells of plants.

The shape of these tiny glass fragments is different, depending on which plants they come from.

The researchers were able to identify evidence of manioc (cassava, yuca) that were grown 10,350 years ago. Squash appears 10,250 years ago, and maize more recently - just 6,850 years ago.

"This is quite surprising," said Dr Lombardo.

"This is Amazonia, this is one of these places that a few years ago we thought to be like a virgin forest, an untouched environment."

"Now we're finding this evidence that people were living there 10,500 years ago, and they started practising cultivation."

The people who lived at this time probably also survived on sweet potato and peanuts, as well as fish and large herbivores.

The researchers say it's likely that the humans who lived here may have brought their plants with them.

They believe their study is another example of the global impact of the environmental changes being felt as the world warmed up at the end of the last ice age.

"It's interesting in that it confirms again that domestication begins at the start of the Holocene period when we have this climate change that we see as we exit from the ice age," said Dr Lombardo.

"We entered this warm period, when all over the world at the same time, people start cultivating."

The study has been published in the journal Nature.

https://www.bbc.co.uk/news/science-environment-52217636

[CaaC (John)+]

Biggest cosmic mystery 'step closer' to solution

Stars, galaxies, planets, pretty much everything that makes up our everyday lives owes its existence to a cosmic quirk.

The nature of this quirk, which allowed the matter to dominate the Universe at the expense of antimatter, remains a mystery.

Now, results from an experiment in Japan could help researchers solve the puzzle - one of the biggest in science.

It hinges on a difference in the way matter and antimatter particles behave.

The world that's familiar to us - including all the everyday objects we can touch - is made up of matter. The fundamental building blocks of matter are sub-atomic particles, such as electrons, quarks and neutrinos.

• A new clue to anti-matter mystery
• Supernova 'stream' in the lab's sights

But the matter has a shadowy counterpart called antimatter. Each sub-atomic particle of ordinary matter has a corresponding "antiparticle".

Today, there is far more matter than antimatter in the Universe. But it wasn't always this way.

The Big Bang should have created matter and antimatter in equal amounts.

FULL REPORT

[CaaC (John)+]

Tsunami risk identified near the future Indonesian capital

Scientists have identified a potential tsunami risk in the region chosen by Indonesia for its new capital.

The researchers mapped evidence of multiple ancient underwater landslides in the Makassar Strait between the islands of Borneo and Sulawesi.

If the largest of these were repeated today, it would generate tsunami capable of inundating Balikpapan Bay - an area close to the proposed capital.

But the international team cautions against an overreaction.

"We still have a lot more work to do to properly assess the situation. That said, this is something that Indonesian governments probably should have on the risk register somewhere - even if we're only talking about 'low frequency, high impact' events," said Dr Uisdean Nicholson from Heriot-Watt University, UK.

His British-Indonesian research team used seismic data to investigate the sediments and their structure on the Makassar seafloor.

The survey revealed 19 distinct zones along the strait where mud, sand and silt have tumbled downslope into deeper waters.

Some of these slides involved hundreds of cubic kilometres of material - volumes that are more than capable of disturbing the water column, and of producing large waves at the sea surface.

• When your capital is sinking... Start again?
• An ancient tsunami may have struck the Falkland Islands
• Giant blocks from Anak Krakatau litter ocean floor

"These landslides - or mass transport deposits (MTDs) as we call them - are quite easy to spot in the seismic data," explained Aberdeen University's Dr Rachel Brackenridge, the lead author on the paper describing the research.

"They're lens-shaped and the sediments within them are chaotic; they're not flat, ordered, tramline-like layers you expect to find. I mapped 19 events, but that's limited by the resolution of the data. There will be other, smaller events I just couldn't see," she told BBC News.

All of the MTDs are on the western side of the deep (3,000m) channel that runs through the Makassar Strait. And they're also predominantly to the south of the outlet delta for Borneo island''s Mahakam River, which is discharging something in the order of 8 million cubic metres of sediment every year.

The team thinks this material is picked up by currents in the strait and then dumped where the shallower parts of the seafloor fall away into the deep.

The steep piles of sediment sculpted over time ultimately collapse downslope triggered perhaps by the shaking from a local earthquake. This is Indonesia after all.

What the team cannot say right now is when the submarine landslides occurred. The researchers' best estimate is within the current geological period - so, within the last 2.6 million years.

Cores extracted from the MTDs could better constrain their age and the frequency of slope failure - and funding is being sought to do just this.

The team plans also to visit the coastal areas of Borneo to look for physical evidence of ancient tsunami and to model the type of waves that could hit the coastline.

Ben Sapiie, from the Bandung Institute of Technology in Indonesia, said: "This research enriches the Indonesian geological and geophysical communities' knowledge about sedimentation and landslide hazards in the Makassar Strait. The future of earth sciences research is using an integrated, multi-scientific approach with international collaborators."

Prof Dan Parsons is director of the Energy and Environment Institute at Hull University. His group also studies submarine landslides around the world.

He told BBC News: "What is interesting here is how these sediments are being re-worked and piled up over time in the Makassar Straight by oceanic currents.

"This sediment builds up and then fails when it gets unstable. What is then the key is identifying the tipping point, or the trigger, that results in the failure. We have been doing similar work in fjords, exploring the multiple triggers and the magnitude and frequency of the failures that can occur.

"The biggest failures and the largest tsunami will likely occur when sediment delivery rate is very high but the triggers are infrequent, such that when the failures occur they are very large."

Indonesia experienced two landslide-driven tsunami events in 2018 - when the side of the Anak Krakatau volcano collapsed and separately when a quake triggered slope failures in Sulawesi's Palu Bay.

So awareness is certainly growing that tsunami can come from sources other than a seafloor megathrust earthquake like the one-off Sumatra in 2004 which wreaked havoc right around the Indian Ocean.

President Joko Widodo announced last year that Indonesia would move its capital from Jakarta to Borneo.

The new administrative centre is to be built across two regencies - Kutai Kartanegara and North Penajam Paser - in East Kalimantan province, close to the existing cities of Balikpapan and Samarinda.

The seafloor study has been published by the Geological Society of London.

https://www.bbc.co.uk/news/science-environment-52388352

 

[CaaC (John)+]

Science & Environment 

Antarctic meteorites yield global bombardment rate

A team of UK scientists has provided a new estimate for the amount of space rock falling to Earth each year.

It's in excess of 16,000kg. This is for meteorite material above 50g in mass.

It doesn't take account of the dust that's continuously settling on the planet, and of course, just occasionally we'll be hit by a real whopper of an asteroid that will skew the numbers.

But the estimate is said to give a good sense of the general quantity of rocky debris raining down from space.

"The vast, vast majority of objects to hit the Earth are really small," explained Dr Geoff Evatt.

"We're talking about objects for which, when they strike the ground, the fragments sum together to over 50g. So, typically, 50g-10kg in total. Objects bigger than this are very, very infrequent," the University of Manchester mathematician told BBC News.

• UK meteorite hunt thwarted by equipment damage
• 'Dinosaurs walked through Antarctic rainforests'
• Dancing gargantuan black holes perform on cue

One of the other outcomes of the study - produced in conjunction with colleagues from Cambridge University, Imperial College London, and the British Antarctic Survey - is that it enables a risk assessment to be made for the entire planet.

This reveals that the number of falls at the poles is about 60% of what you would expect at the equator.

It explains why you would absolutely want to put any long-term contingency facilities at higher latitudes.

The Global Seed Vault, for example, which aims to retain copies of Earth's plants in case of a crisis, is sited at 78 degrees North on the Svalbard archipelago.

The new estimate, published in the journal Geology, grew out of the project to undertake the first UK-dedicated meteorite hunt in the Antarctic.

Researchers involved in that effort wanted to be sure they would visit the most productive areas to perform such a quest.

The White Continent is the place on Earth where most meteorites have been recovered - with good reason: the "black on white" contrast of fallen space rocks on snow and ice makes searching a lot easier.

And hunters will typically go to places where the movement of the ice sheet concentrates the meteoritic material - so-called stranding zones.

Dr Evatt and colleagues worked out how many objects ought to be in their chosen area - a place called the Outer Recovery Ice Fields, close to the Shackleton range of mountains in East Antarctica.

And they were virtually bang on with their expectation, finding close to 120 meteorites in two systematic searches over 2019 and 2020.

But having worked out a reliable flux for the number of falls at their chosen terrain, the scientists realised they could then use this knowledge to anchor a global assessment.

This incorporated orbital mechanics - how Earth's gravity will pull in nearby passing material - to work out how rates might vary by latitude. The model outputs a grand total of about 17,000 falls a year.

And this can be tested by looking at the data from fireball events. Satellites in orbit tracking the lightning in storms will also catch the blazing trail of a space rock plunging into the atmosphere.

"Satellites monitor these explosions in the sky, working out the energy of the events and also the longitude and latitude of where they happen. And from this, you can see how they vary across the globe with latitude, and very nicely the curve you get from these fireballs fits with what we independently modelled using purely an applied mathematical approach," said Dr Evatt.

Prof Sara Russell leads the planetary materials group at the Natural History Museum in London. She wasn't involved in the research but commented: "I think this is an amazing study, and this estimate sounds like it is in the right sort of ballpark.

"We think a total of about 40,000 tonnes (so 40,000,000 kg) of extraterrestrial material falls to Earth each year, but the vast majority of this is in the form of tiny dust grains.

"This is a very difficult measurement to make with any accuracy and only about half a dozen meteorites are actually seen to fall each year, but of course almost all meteorite falls are not observed because they fall in the sea, in unpopulated areas or just no-one is looking!" she told BBC News.

https://www.bbc.co.uk/news/science-environment-52465237

[nudge+]

A huge breakthrough in malaria control.

https://www.bbc.com/news/health-52530828

[CaaC (John)+]

Science & Environment

Scientists explain the magnetic pole's wanderings

European scientists think they can now describe with confidence what's driving the drift of the North Magnetic Pole.

It's shifted in recent years away from Canada towards Siberia.

And this rapid movement has required more frequent updates to navigation systems, including those that operate the mapping functions in smartphones.

A team, led from Leeds University, says the behaviour is explained by the competition of two magnetic "blobs" on the edge of the Earth's outer core.

Changes in the flow of molten material in the planet's interior have altered the strength of the above regions of negative magnetic flux.

FULL REPORT

[CaaC (John)+]

Science & Environment 

Iceye's small radar satellites achieve a big capability

European "new space" company Iceye has demonstrated a radar technique in its small satellites that have in the past been performed only by the biggest of spacecraft.

Called Interferometric Synthetic Aperture Radar (InSar), it involves making repeat images of a location to detect millimetric changes in height.

The approach has myriad applications, from tracking subsidence to tracing ground ruptures from Earthquakes.

Iceye's satellites weigh under 100kg.

The high-fidelity spacecraft that have traditionally done this work have weighed perhaps a couple of tonnes.

It's another example of how emerging space companies are wringing capability out of small packages - something they can do as they exploit the very latest commercial, "off-the-shelf" technologies, such as those developed for consumer electronics.

• Start-up's space radar has super-sharp eyes
• Space agency teams with Finnish start-up

Iceye, based in Helsinki, Finland, currently operates four radar satellites in orbit but has plans for many more.

InSar marks an important milestone for the company because it is one of the most difficult techniques to master.

It requires very precise control of a spacecraft to ensure that when it comes back over the target scene, its images are coherent.

"It's all down to the details," said Rafal Modrzewski, CEO at Iceye.

"First you have to inject your satellite into its correct orbit, and then precisely monitor and maintain that orbit. And then your radar instrument needs to be precise enough that it retains coherence between consecutive images. Only then it works. These precision achievements tend to be the domain of high-fidelity, expensive systems. It's taken quite a bit of development on our part to get there," he told BBC News.

Iceye has been working very closely with an Austrian firm called Enpulsion, which makes small ion engines for satellites. The European Space Agency (Esa), whose own satellites have very much pioneered InSar, has also been advising on the project.

Like radar images in general, InSar data requires some expertise to interpret. Analysts will use interferograms to illustrate changes in the shape of the ground below from one satellite pass to the next. Each map is made up of a series of coloured "fringes". Each fringe will describe the movement either away or towards the spacecraft.

The technique is used to monitor the stability of infrastructures, such as buildings and bridges. Scientists employ the approach to watch for sagging on a hill slope which might indicate a landslide is imminent, or to alert them to a bulge in the flank of a volcano that's about to erupt.

Leeds University's Prof Tim Wright is director of the Centre for Observation and Modelling of Earthquakes, Volcanoes and Tectonics (Comet). His group regularly exploits InSar data acquired by governmental radar satellites, such as Esa's Sentinel-1 system.

He commented. "The possibility of doing InSar with these microsatellites at very high resolution with rapid revisit time is really exciting and could open up many new monitoring applications (largely commercial I think)." But he added that it was now for Iceye to show it could deliver regular, quality interferograms.

At the moment, the repeat over the same ground target is 18 days. But with many more satellites in orbit, this will come down. Iceye wants to get under 24 hours.

https://www.bbc.co.uk/news/science-environment-52560809

 

[CaaC (John)+]

POPULAR SCIENCE

ENVIRONMENT 

Pangea Broke Apart As Fast As Fingernails Grow

That's pretty fast for a 20-mile thick continent

Hang on to your landmasses: we now know that the continents split apart in a big hurry.

University of Sydney researchers studying seismic data from hundreds of millions of years ago found that tectonic plates experience fast and slow periods of motion. The crust, which is up to 20 miles thick in places, would slowly stretch and then suddenly move at 20 times its previous rate. "It's the equivalent of moving around as a pedestrian to moving around in a very fast BMW," Dietmar Muller, an author of the study, told the New York Times. When the connections between continents became too weak to resist forces tearing them apart, the crust moved at 20 millimetres per year. That's nearly the speed at which fingernails grow.

The study resulted in a publicly available computer simulation of Pangea's movements, available here.

 

Edited May 7, 2020 by CaaC (John)

[Stan]

Sir David Attenborough is 94 years old today!

Hope he is remaining safe in these times! What a hero.

[CaaC (John)+]

Science & Environment

Ozone layer: Concern grows over the threat from replacement chemicals

Substances used for air conditioning in almost all new cars are building up in the environment and may pose a threat to human health, researchers say.

These "ozone-friendly" chemicals have been introduced to replace products that were damaging the ozone layer.

Now widely used across the industry, these alternatives do not break down in the environment.

Scientists have now found increasing levels of these chemicals in Arctic ice samples dating back to the 1990s.

• 'Ozone hole vigilance still required'
• China confirmed as the source of the rise in CFCs
• 'Fastest growing' warming gases face a ban

FULL REPORT

[CaaC (John)+]

Earth's Magnetic North Is Moving From Canada to Russia, And We May Finally Know Why

Our planet wears its magnetic field like an oversized coat that just won't sit comfortably. All that sliding means the north magnetic pole is destined to move ever closer to Siberia's coastline over the coming decade.

There's no conspiracy behind it - but the geological forces responsible have been something of a mystery. Now, we might be a little closer to understanding what's going on.

Researchers from the University of Leeds in the UK and the Technical University of Denmark have analysed 20 years of satellite data, finding that a monolithic competition between two lobes of differing magnetic force near the core is likely to be behind the pole's wanderlust.   

When the precise position of Earth's magnetic north was located for the first time back in 1831, it was squarely in Canada's corner of the Arctic, on the Boothia Peninsula in the territory of Nunavut.

Ever since fresh sets of measurements have recorded this spot drift north by an average of around 15 kilometres (about 9 miles) every year.

Advanced technology means we can now keep a careful watch on the pole's location with unprecedented accuracy. Prior to the 1970s, the north magnetic pole's position was like a drunken stagger. Since then, it's had a mission, marching in a straight line, building speed.

Since the 1990s, its movement has quadrupled in speed, to a current rate of between 50 and 60 kilometres (about 30 and 37 miles) a year. In late 2017, the pole's sprint brought it within 390 kilometres (240 miles) of the geographical north pole.

On its current trajectory, we can expect it to be anywhere between 390 and 660 kilometres (240 and 410 miles) further along its journey in ten years, bringing it within a whisker of the northern limits of the East Siberian Sea.

The rapid displacement is a concern for navigation systems that rely on pinpoint calculations of the pole's location, forcing the US National Geophysical Data Center to fast track its usual updates to the World Magnetic Model last year.

What the world really needs is a solid idea of the physical mechanisms behind this displacement, allowing for accurate predictions on the planet's magnetic movements.

So Earth scientists Philip Livermore and Matthew Bayliff from the University of Leeds in the UK and Christopher Finlay from the Technical University of Denmark reviewed 20 years of geomagnetic data from the ESA's Swarm mission.

The pole's heading lines up neatly with two anomalies called negative magnetic fluxes, one deep beneath Canada, and the other below Siberia.

"The importance of these two patches in determining the structure of the field close to the north magnetic pole has been well known for several centuries," the researchers note in their recently published report.

These large lobes of magnetism grow and shrink with time, having a profound effect on the magnetic field we perceive on the surface.

Between 1970 and 1999, changes to interactions between the flowing mantle and the planet's dense, spinning core caused the patch beneath Canada to elongate, reducing the corresponding magnetic field's strength to drop up top.

"Now historically, the Canadian patch has been winning the war and that's why the pole has been centred over Canada," Livermore told BBC Radio 4's Today programme in a recent interview.

"But in the last few decades, the Canadian patch has weakened and the Siberian patch has strengthened slightly, and that explains why the pole has suddenly accelerated away from its historical position."

While this means we can expect the pole to continue racing for a little longer, it doesn't tell us precisely where it will stop, how long it will stop for, or when it might return.

There is an incredible amount we don't know about the engine whirring away inside our planet's guts.

Given that extensive geological records hint at significant fluctuations in its protective magnetic field, we really ought to know a lot more than we do.

We're going to need more models like this if we're to have a hope of predicting just where our planet's poles will end up in the future.

This research was published in Nature Geoscience.

https://www.msn.com/en-gb/news/techandscience/earths-magnetic-north-is-moving-from-canada-to-russia-and-we-may-finally-know-why/ar-BB148dbk

[CaaC (John)+]

Science & Environment

The project seeks the 4D view of Earth's mantle

Some of the most sophisticated models of the Earth's interior ever constructed will be produced in a new project led from Cardiff University.

Researchers want to simulate the behaviour of the mantle.

This solid rock layer, which resides between the planet's core and crust, moves very slowly over time - roughly at the speed that a fingernail grows.

The scientists will investigate its complex pattern of upwellings and downwellings.

The team hopes its new circulation models will provide fresh insights into how the mantle has influenced the Earth's surface over hundreds of millions of years.

"In the same way that the study of DNA has given us a whole new framework to understand biology, evolution and even this coronavirus we now face - so I want to look to the interior of the Earth to better understand how our planet, our single and sole 'spaceship', really works," project leader Prof Huw Davies told BBC News.

• How Greenland scorched its underside
• When we discovered how the Earth really works
• Space view of Earth's magnetic rocks

Everyone is now familiar with plate tectonics - the description of how the rigid outer shell of our planet (its lithosphere) moves and is recycled.

Great strides have been made in developing this theory in the 50 years since it came to prominence.

For example, early ideas suggested the plates simply rode convection cells in the mantle like groceries on a supermarket check-out belt.

But we can now see that it's actually the weight of the ocean plates where they underthrust the continents that play the major role in driving this remarkable system.

Cold, dense rock at plate margins pulls on everything behind as it sinks into the mantle. And like the slinky dog that's started its journey downstairs, it needs little encouragement to maintain the momentum.

Nonetheless, what goes down is coming back up because the heat of the interior has to be managed and redistributed.

The new project will focus on the where and how of the upwellings, mapping the different regions of temperature, density, and velocity.

Its supercomputer simulations will be constrained by the state of the art knowledge in rock physics, chemistry and magnetism.

Thanks to seismology, the study of how waves of energy from quakes move through the Earth, we have a very good picture of what the planet's interior looks like today. And the team's models, when they're run forwards and backwards, will have to reproduce this anchoring snapshot.

The goal, says Prof Davies, is to get an accurate representation of behaviour back to about one billion years into the past.

A key target is to understand the upwellings that ultimately result in "hotspots" at the Earth's surface - the places where there have been colossal outpourings of lava and gas through geologic history.

"These are what we call the Large Igneous Provinces or LIPs," explained Prof Davies.

"There hasn't been anything like this since the Columbia River flood basalts in North America just over 10 million years ago. So, they're rare. And thank goodness, because they can be absolutely catastrophic.

"The Siberian Traps which cover a large part of West Siberia match up with the largest extinction on Earth. A lot of the great extinction events are linked to these LIPs."

The £3m project is funded by the Natural Environment Research Council and will run for four years.

Prof Davies' team has members from the universities of Bristol, Cambridge, Oxford, Leeds, Liverpool, Imperial College London, Royal Holloway University of London, and University College London - in addition to Cardiff.

https://www.bbc.co.uk/news/science-environment-52701935

[CaaC (John)+]

Science & Environment

Dinosaur asteroid's trajectory was 'perfect storm'

A clear picture is emerging of why the asteroid that struck Earth 66 million years ago was so catastrophic.

The space object, which wiped out 75% of all species including the dinosaurs, hit the worst possible place on the planet and - according to new research - at the most lethal angle.

Investigations at the crater site, together with computer simulations, suggest the impactor dug into the crust at an inclination of up to 60 degrees.

This exacerbated the climatic fallout.

We know that the target rocks, in what is now the Gulf of Mexico, contained huge volumes of sulphur from the mineral gypsum. When this material was thrown high into the atmosphere and mixed with water vapour, it produced a "global winter".

And the angle of attack ensured this environmental crisis was intense and prolonged.

"At 45 to 60 degrees, the impact is very efficient at vaporising and ejecting debris to high altitude. If the impact happens at shallower or much steeper angles, the amount of material that's put into the atmosphere that can then have climate-changing effects is significantly less," explained Prof Gareth Collins from Imperial College London.

"It's evident that the nature of the location where this event happened, together with the impact angle, made for a perfect storm," he told BBC News.

The majority of plant and animal life on Earth succumbed to the challenging conditions.

Prof Collins' and colleagues' work is published in the journal Nature Communications.

FULL REPORT

Edited May 27, 2020 by CaaC (John)

[Lucas]

Apparently you can view the SpaceX rocket tonight?

https://www.google.com/amp/s/www.dailymail.co.uk/sciencetech/article-8360713/amp/SpaceX-rocket-shoot-Britains-skies-9-50pm-TONIGHT.html

It sounds cool, but in reality, are we really going to be able to notice anything?

[Stan]

Just now, Lucas said:

Apparently you can view the SpaceX rocket tonight?

https://www.google.com/amp/s/www.dailymail.co.uk/sciencetech/article-8360713/amp/SpaceX-rocket-shoot-Britains-skies-9-50pm-TONIGHT.html

It sounds cool, but in reality, are we really going to be able to notice anything?

Yep

https://talkfootball365.com/topic/6885-space-the-final-frontier/?page=20&tab=comments#comment-403825

 

[Lucas]

1 minute ago, Stan said:

Yep

https://talkfootball365.com/topic/6885-space-the-final-frontier/?page=20&tab=comments#comment-403825

 

My bad.

That is why I should stick to my usual haunts on the forum.

[Stan]

1 minute ago, Lucas said:

My bad.

That is why I should stick to my usual haunts on the forum.

No! 

Every day is a school day, even in lockdown!

[CaaC (John)+]

Biggest UK solar plant approved

The go-ahead has been given to the UK’s biggest solar farm, stretching 900 acres on the north Kent coast.

The government has approved the controversial scheme, which will supply power to 91,000 homes.

The project could include one of the world’s largest energy storage systems.

But it has been fiercely opposed by many local people, and it’s divided, green groups. Greenpeace, the RSPB and the countryside charity CPRE are against the plan.

They say it’s industrialising the countryside - and may harm an adjacent wildlife site.

But Friends of the Earth offered qualified support, on the grounds that the current intensively-farmed land was bad for wildlife anyway.

Their spokesperson Mike Childs said: “No-one wants to see damage to local habitats, but this is not some lovely, untouched meadow.

“Changing the use of the site from intensive agriculture will reduce the high level of chemicals currently harming insects and wildlife - but we have to hold the developers to account”.

Rooftop panels?

Environmentalists want the developers to offer free rooftop solar panels to local people who are protesting against the solar farm – and especially against the giant energy storage unit, which they fear may prove an explosion risk.

The facility will use 25 acres of the total land and the countryside charity CPRE says the proposed battery storage system has caused fires and explosions around the world.

The developers Wirsol Energy and Hive Energy say it’s safe. They maintain the subsidy-free project will be one of the lowest-cost power generators in the UK and will bring local councils £1m every year that it is running.

Cheap panels

In 2015, the government controversially announced it would phase out subsidies from solar power to a howl of protest from the industry.

But the cost of solar panels has tumbled by two thirds since 2010.

The Energy Secretary Alok Sharma said the decision was taken after careful consideration – but said the project would be a world leader in solar and power storage.

https://www.bbc.co.uk/news/business-52841223

[CaaC (John)+]

‘DNA fingerprinting’ may help to decipher Dead Sea Scrolls

Researchers have analysed the DNA of the animal skins the Dead Sea Scrolls were printed on.

Made up of more than 25,000 fragments of ancient manuscripts, the Dead Sea Scrolls are perhaps the world’s most challenging jigsaw puzzle. Since their discovery in the 1940s and 50s, researchers have worked to painstakingly piece them together with only limited success.

Now, researchers at Tel Aviv University have developed a technique that may help to decipher the ancient scriptures using ‘DNA fingerprints’ lifted from the animal skins on which the enigmatic texts were written.

“The discovery of the 2,000-year-old Dead Sea Scrolls is one of the most important archaeological discoveries ever made,” says Oded Rechavi of Tel Aviv University in Israel.

“However, it poses two major challenges: first, most of them were not found intact but rather disintegrated into thousands of fragments, which had to be sorted and pieced together, with no prior knowledge on how many pieces have been lost forever, or – in the case of non-biblical compositions – how the original text should read.

“Depending on the classification of each fragment, the interpretation of any given text could change dramatically.”

The team extracted ancient DNA of the animals that were used to make the parchments and then used forensic-like analysis to establish genetic relationships between the different fragments.

A tiny fragment of the scrolls being sampled for testing © Courtesy of the Israel Antiquities Authority, Photographer Shai Halevi

The DNA sequences revealed that the parchments were mostly made from sheep and some from a cow. They reasoned that pieces made from the skin of the same animal must be related and that scrolls from closely related animals were more likely to fit together than those from more genetically different animals.

They found that pieces previously thought to belong together in a copy of the biblical prophetic book of Jeremiah came from a sheep and a cow, suggesting they don’t in fact belong together.

They also found that different copies of a non-biblical, liturgical work known as the Songs of the Sabbath Sacrifice, found in Qumran and Masada were significantly genetically different, suggesting that the work was more widespread than originally believed.

“What we learn from the scrolls is probably relevant also to what happened in the country at the time,” said Prof Noam Mizrahi.

“As the Songs of the Sabbath Sacrifice foreshadows revolutionary developments in poetic design and religious thinking, this conclusion has implications for the history of Western mysticism and Jewish liturgy.”

The researchers now hope to build on their initial success by testing more samples to add to the database with the end goal of creating a Dead Sea Scroll genome.

https://www.sciencefocus.com/news/dna-fingerprinting-may-help-to-decipher-dead-sea-scrolls/

[CaaC (John)+]

Dark matter hunt yields unexplained signal

An experiment searching for signs of elusive dark matter has detected an unexplained signal.

Scientists working on the Xenon1T experiment have detected more activity within their detector than they would otherwise expect.

This "excess of events" could point to the existence of a previously undetected dark matter particle called an axion.

Dark matter comprises 85% of matter in the cosmos, but its nature is unknown.

Whatever it is, it does not reflect or emit detectable light, hence the name.

There are three potential explanations for the new signal from the Xenon1T experiment. Two require new physics to explain, while one of them is consistent with a hypothesised dark matter particle called a solar axion.

The findings have been published on the Arxiv pre-print server.

So far, scientists have only observed indirect evidence of dark matter. A definitive, direct detection of dark matter particles has yet to be made.

• Dark matter becomes less 'ghostly'
• Dark matter map yields first results

There are several theories to account for what that particle might be like. The most favoured one has been the WIMP or Weakly Interacting Massive Particle.

Physicists working on the Xenon series of experiments have spent more than a decade hunting for signs of these WIMPs. But the search has been fruitless.

But Xenon1T, the most recent iteration was also sensitive to other candidate particles.

Background noise

The experiment was operated deep underground at the Gran Sasso facility in Italy, from 2016 to 2018.

Its detector was filled with 3.2 tonnes of ultra-pure liquefied xenon, two tonnes of which served as a "target" for interactions between the xenon atoms and other particles that were passing through.

When a particle crosses the target, it can generate tiny flashes of light and free electrons from a xenon atom.

Most of these interactions - also known as events - are with particles we already know about, such as muons, cosmic rays and neutrinos. This constitutes what scientists refer to as the background signal.

A potential signal from an undiscovered particle needs to be strong enough to rise above this background noise.

Scientists carefully estimated the number of background events in Xenon1T. They expected to see roughly 232, but the experiment instead saw 285 - an excess of 53 events.

One explanation could be a new, previously unconsidered source of background contamination, caused by the presence of tiny amounts of tritium in the Xenon1T detector.

It could also be due to neutrinos, trillions of which pass through your body, unhindered, every second. One explanation could be that the magnetic moment (a property of all particles) of neutrinos is larger than its value in the Standard Model, which categorises the elementary particles in physics.

New physics

This would be a strong hint that some other new physics is needed to explain it.

However, the excess is most consistent with a signal from solar axions, a very light as-yet undetected particle, which is also a dark matter candidate.

In statistical terms, the solar axion hypothesis has a significance of 3.5 sigmas.

While this significance is fairly high, it is not large enough to conclude that axions exist. Five sigmas are generally the accepted threshold for a discovery.

The significance of both the tritium and neutrino magnetic moment hypotheses corresponds to 3.2 sigmas, meaning that they are also consistent with the data.

Scientists working on the Xenon collaboration are currently upgrading to a different iteration called XENONnT. With better data from this future version, they are confident they will soon find out whether the excess is a statistical fluke, a background contaminant, or something far more exciting.

https://www.bbc.co.uk/news/science-environment-53085260

Edited June 18, 2020 by CaaC (John)

[CaaC (John)+]

Science & Environment 

Britain's 'blindingly cool' engineering innovation

Ted Humble-Smith is a conceptual still-life photographer. He's well known for his fashion work. Ted can take a lipstick or a watch and with his extraordinary vision and skill turn the beautiful into something even more gorgeous.

But speak to him for just a few minutes and it's clear he sees not just the colour and form of his subjects, but the engineering that underpins their design.

In fact, it's obvious Ted has a passion for it. He points to the 4-inch stiletto heel.

"Everyone laughs when I talk about it," he told me. "But you have this thing that's so elegant, so beautiful - and yet at the same time, there has to be some serious engineering and mathematics in there as well.

"Eight stones at least is going through a square centimetre. These are big loads but you rarely see people snap their heels these days."

Ted has just put his inquisitive eye to a project for the Royal Academy of Engineering.

He's produced a series of images to celebrate the 50th anniversary of the MacRobert Award, which honours examples of remarkable British innovation. From the aerodynamic design of the Severn Bridge to the composite wing of an Airbus jet.

FULL REPORT AND MORE PHOTOS

Edited June 25, 2020 by CaaC (John)
Add Link