Science & Environment

[CaaC (John)+]

How a 'forgotten' 600-year-old tsunami changed history

Megan Gannon

On Dec. 26, 2004, roiling tides as high as 100 feet rushed onto the shores of Aceh, the Indonesian province on the northwest tip of Sumatra.

An undersea earthquake had struck just off the coast and triggered a destructive tsunami, which hit shorelines all along the Indian Ocean as far away as Somalia. More than 160,000 people were killed in Aceh alone, and even more, were displaced.

A similar tsunami appears to have wiped out coastal villages in Aceh more than 600 years ago, and the resulting devastation may have played a role in the rise of the powerful Aceh Sultanate, according to new evidence, published today in the Proceedings of the National Academy of Sciences.

In 2006, archaeologist Patrick Daly was working with Acehnese authorities to preserve cultural and religious sites damaged by the 2004 tsunami when he saw beautifully carved historic Muslim gravestones toppled over and eroding away along the coastline

Historic grave markers revealed by the 2004 Indian Ocean tsunami prompted researchers to look for evidence of earlier tsunamis.

"To see them thrown up and tossed aside, that was quite heartbreaking," he says.

Daly started wondering how often these tsunamis had happened in the past, and if so, how they affected the people living in Aceh. The northwest tip of Sumatra, where Aceh's capital Banda Aceh is now, was either the first or last port of call for ships crossing the Bay of Bengal, and the Aceh Sultanate that arose there in the 16th century became one of the few Southeast Asian powers to successfully resist colonialism for centuries. Archaeologists, however, didn't have much hard evidence for settlements in the area before the 17th century.

Tsunamis101

Daly, who works at the Earth Observatory of Singapore, and his colleagues at Syiah Kuala University in Aceh began systematically studying the coast, fanning out to about 40 coastal villages to sit down with elders and map any traces of historic human presence, such as gravestones, ceramic fragments, and old mosque foundations.

"The very first map I got back told most of the story," Daly says. "It was stunning. We can see all these very discrete concretions of material along the coast. Ten settlements came up really distinctly."

Based on the age of the ceramic scatters in these settlements, the researchers found something even more striking. The coastal villages all seem to pop up around the 11th and 12th centuries, but then all nine low-lying settlements along a 25-mile section of coast seem to have been abandoned around 1400.

Recently discovered geologic evidence suggested that a tsunami had struck the region in 1394, but, Daly says, ""We had no idea of the extent of it—how big, how powerful, how destructive was it." The new archaeological evidence suggests the tsunami, possibly par with the 2004 event, destroyed all the low-lying villages in the region.

The one Acehnese settlement that seemed to survive the 1394 tsunami was a hilltop site out of reach of the tides. Daly and his colleagues have identified the settlement as Lamri, a trading site known from historical records on the medieval maritime Silk Road. At Lamri, the researchers found high-end ceramics from all different parts of China and even as far away as Syria that they didn't see in the low-lying villages.

Lamri, however, went into rapid decline around the beginning 16th century. Just a few decades earlier, people had started rebuilding in the villages that had been destroyed by the tsunami. Trade was getting rerouted to those low-lying areas, as evidenced by the uptick in higher quality ceramics and gravestones with names of elites from other parts of the Straits of Malacca, which separates Sumatra from the Malay Peninsula.

Daly and his colleagues don't think the low-lying coastal areas were resettled by local survivors moving back home. Rather, they believe the tsunami destruction offered prime, vacated real estate for Muslim traders who were being displaced elsewhere as Europeans started vying for influence in the region. (The Portuguese conquered the nearby state of Malacca in 1511.) These newcomers may have formed the core of what became the Aceh Sultanate, a powerful Islamic kingdom.

"You can have a tsunami event followed by a period of absolute renaissance and construction," says Beverly Goodman, a geoarchaeologist at the University of Haifa in Israel, who also studies past tsunamis. (Goodman was not part of the study.)

Geologists and archaeologists hope that reconstructing past tsunamis can help us better understand modern risks.

"If we rely only on the record that we're aware of, we end up significantly underestimating how often and how big the impact of tsunamis is around the world," says Goodman.

She noted that because of the 2004 event, Aceh was shown to be very vulnerable. But the same methods of this new study, which Goodman wasn't involved in, could help recognize vulnerability in places that haven't had a recently recorded event.

"This type of research is really important for getting those older records together to better understand what the risk factors are," Goodman says. "Using sediment records and archaeological records is really critical for filling in those gaps."

The greater challenge is perhaps figuring out how to appropriately adapt to very rare events.

"If you tell people that some time in the next couple of centuries there could be another tsunami, but we can't tell you when, and it will wipe the whole area out, a lot of people are willing to live with that risk," Daly says.

https://www.msn.com/en-gb/news/offbeat/how-a-forgotten-600-year-old-tsunami-changed-history/ar-AAC4XcD?ocid=chromentp

[CaaC (John)+]

Scientists close in on hidden Scottish meteorite crater

Scientists think the time has come for a full geophysical survey of The Minch, to see if the Scottish strait is hiding an ancient meteorite crater.

The idea that such a structure lies between the Western Isles and mainland Scotland was first raised back in 2008.

They found evidence on the Highlands coast for the rocky debris that would have been produced by a giant impact.

Now, the team from Oxford and Aberdeen universities believes it can pinpoint where the space object fell to Earth.

Writing in the Journal of the Geological Society,   Dr Ken Amor and colleagues say this location is centred about 15-20km west-northwest of Enard Bay - part way across The Minch towards Stornoway in the Outer Hebrides.

The feature would be buried deep under the seafloor, they add.

It's an intriguing prospect. The evidence gathered so far suggests the event occurred about 1.2 billion years ago when the continents were arranged very differently from how they are now, and life on our planet would have existed almost exclusively in the oceans.

The key supporting evidence is a group of reddish-coloured rocks on the eastern side of The Minch known as the Stac Fada deposit.

These are determined to be ejecta from the impact - the material hurled outwards when a 1-2km-wide object slammed into what was probably then some kind of rift valley.

The rocks are fragmented and contain melt particles, and also what geologists term shocked quartz - a type of mineral that has at some point been subjected to enormous pressures.

Shocked quartz is very often associated with meteorite events.

The latest examinations of the Stac Fada deposit have now given the researchers some directional information that allows them to be more precise about where the ejecta came from.

"If you imagine debris flowing out in a big cloud across the landscape, hugging the ground, eventually that material slows down and comes to rest. But it's the stuff out in front that stops first while the stuff behind is still pushing forward and it overlaps what's in front," explained Dr Amor.

"That's what we see and it gives us a strong directional indicator that we can trace backwards.

"Also, we've examined the orientation of magnetic particles within the fabric of the rock at several locations, and this too allows us to triangulate back to an origin," the Oxford researcher told BBC News.

The lines converge out in The Minch.

The team is examining some seismic surveys that were done in the 1970s as part of an oil prospecting programme, but they are of poor quality.

Likewise, they are investigating gravity data. This indicates something anomalous in the strait, but again it is all somewhat uncertain.

"What we really need is a new high-resolution geophysical survey - a 3D seismic survey," said Dr Amor.

"Unfortunately, being offshore that would cost a lot of money. I shall be putting in a grant proposal to do some seismic work. That would be a first step and would greatly assist the definition of any impact structure."

https://www.bbc.co.uk/news/science-environment-48560989

[Stan]

Not sure when exactly this was but this is pretty cool if not terrifying at the same time! 

 

[CaaC (John)+]

 

 

 

1 hour ago, Stan said:

Not sure when exactly this was but this is pretty cool if not terrifying at the same time! 

 

Mother nature at it's awesome best @Stan 

 

 

Edited June 10, 2019 by CaaC (John)

[CaaC (John)+]

1 hour ago, Stan said:

Not sure when exactly this was but this is pretty cool if not terrifying at the same time! 

Forget that date above @Stan, that's not been updated from Wikipedia, just saw this (below) on MSN

 

Volcano alert issued as 7km-high ash cloud sparks panic

 8 hrs ago

Officials have warned of more potential eruptions from an active volcano in Indonesia after a huge ash cloud sparked panic among residents.

Mount Sinabung on the island of Sumatra erupted for around nine minutes on Sunday, sending volcanic ash seven kilometres (4.4 miles) into the sky.

Although no casualties were reported, officials monitoring the volcano - which has seen a spike in activity since 2010 - have warned of further eruptions.

Scientists at a Sinabung observatory post said there were aftershocks following the eruption, which happened between midnight and 6 am local time.

Authorities urged people in the area to use face masks and stay indoors to protect themselves against the volcanic ash.

Mount Sinabung, which is more than 8,000ft high, is among Indonesia's most active volcanoes but had been inactive for four centuries before erupting in 2010.

Indonesia has nearly 130 active volcanoes, more than any other country.

The Foreign Office advises against all travel within seven kilometres (4.4 miles) of the Mount Sinabung crater in Kalo Regency - an exclusion zone put in place by local authorities due to ongoing volcanic activity.

"There are many active volcanoes in Indonesia, any of which can erupt with little or no warning," it says.

"This often results in the evacuation of villages within a three to seven-kilometre radius and disruption to air travel in the wider region.

"In the past, repeated eruptions have caused destruction and fatalities."

The volcanic activity comes after hundreds of people died in December when a tsunami swept away hotels and homes in Indonesia.

The disaster happened less than three months after more than 1,500 were feared dead, missing or injured when a 7.5 magnitude tremor and tsunami struck the South East Asian country.

https://www.msn.com/en-gb/news/world/volcano-alert-issued-as-7km-high-ash-cloud-sparks-panic/ar-AACF3o7?li=AAnZ9Ug

 

Edited June 10, 2019 by CaaC (John)
Spelling

[CaaC (John)+]

Antarctica's mysterious ice holes are finally making sense

Kat Eschner

Winter in Antarctica is frigid, persistently dark, violently stormy, and, at least in some years, home to puzzling holes in the sea ice. Known as polynyas, these strange pits “have been this enduring mystery in polar oceanography” since several large ones were first spotted in the 1970s, says Ethan Campbell, a doctoral student in the School of Oceanography at the University of Washington and the author of a new study that offers tantalizing clues about how polynyas form and where they fit in the study of the vast Southern Ocean.

In Antarctica, these craters function as a rest stop for animals like seals who swim under the ice, giving them somewhere to come up for air. However, Campbell says researchers think there’s a lot more to them than that. He and others think the holes—because they’re warm and melt sea ice that holds carbon—also release a significant amount of carbon dioxide into the atmosphere. That makes understanding their role important for climate science.

The researchers used data from three different sources to help them better understand what’s happening with polynyas: satellite footage, sensors strapped to seals (yes, really), and drifting “float robots” that became trapped in a fortunate spot.

Automated robotic devices are crucial to understanding these holes. “We cannot go to Antarctica when the polynya opens in winter. Satellites can see that the sea ice opens, but they cannot look at the effect of this opening on the water column,” Céline Heuzé, a University of Gothenburg oceanographer who wasn't involved in the research but did review the paper before publication, told Popular Science in an email. The robots used in this study are some of the first who can work in the icy waters of Antarctica, allowing researchers to study a place they can’t get to.

Around 200 of the float robots, which travel beneath water and ice, intermittently bobbing to the surface to transmit information, have been released by the Southern Ocean Carbon and Climate Observations and Modeling Project to drift around the ocean and under the ice. In late 2014, two of them entered the Wendell Sea, where the 1970s polynyas opened up, to study the area.

Unexpectedly, two of the floats became trapped on the Maud Rise, an underwater mountain that affects currents, says Campbell. A rotating cylinder of water positioned over the seamounts held the floats in place, he says. Most of the time the floats don’t stay put. When a large polynya opened up there again in 2016 and again in 2017 the floats were in perfect position to send continuous data about the site. “It was just dumb luck. It was incredible,” says Campbell. “In 2017, two of them actually surfaced inside the polynya, which is a very rare occurrence.”

The team also relied on information gathered from “instrumented seals” with temperature probes glued to their heads (we told you). This kind of data collection, which has been going on for more than a decade, gave the team insight into what normal conditions in that ocean region are like since no seals found these polynyas or surfaced within them.

Using these two sources of data alongside satellite data, the research team was able to show evidence that deep ocean mixing—when (relatively) warm upper-ocean water and freezing, slow-moving lower-ocean water mix—occurs within them. This is significant, says Campbell, “because the deep ocean is generally a very quiet place where changes happen slowly. Within these polynyas, changes happen a lot quicker.”

“To me, this study raises even more questions than it answers,” writes Heuzé. These queries include understanding why there was a forty-year gap between the development of big polynyas in the Wendell Sea, as well as why small ones instead of large ones developed in 2018, and how all these ice holes affect atmospheric conditions in the region.

Campbell and his team are still working on some of these questions, and what they find may have a huge impact for the future of climate modelling. Currently, he says, many climate models predict polynyas happening more often than they actually are occurring in the ocean. If researchers can better figure out what conditions lead to polynyas, they could be better equipped to predict when one might form next.

https://www.msn.com/en-gb/news/offbeat/antarcticas-mysterious-ice-holes-are-finally-making-sense/ar-AACGL2H

[CaaC (John)+]

Earth from space: Spectacular volcanic eruptions seen from above

Daniel Bettridge

SLIDES 1/21

 

[CaaC (John)+]

Boaty McBoatface makes major climate change discovery on debut voyage

The yellow submarine dubbed Boaty McBoatface made a significant climate change discovery on its very first research mission.

Boaty McBoatface returned from its first expedition with data which links increasing Antarctic winds to rising sea temperatures.

The mission launched in April 2017 and saw the autonomous vessel explore 110 miles at depths of up to 4,000 metres in the Orkney Passage, a region of the Southern Ocean some 500 miles from the Antarctic Peninsula.

The data collected was published on Monday in the scientific journal PNAS.

It showed Antarctic winds, growing stronger due to the ozone layer's depletion and increasing greenhouse gases, were adding to turbulence deep in the ocean.

Related: 4C rise and record melting hit the Arctic

The turbulence sees warm water at mid-depths mixing with cold, dense water at greater depths, with the warming water from the sea bed then becoming a contributor to rising sea levels.

The finding has not previously been factored into predictive models considering temperature and ocean level rises.

"The data from Boaty McBoatface gave us a completely new way of looking at the deep ocean - the path taken by Boaty created a spatial view of the turbulence near the seafloor," said Dr Eleanor Frajka-Williams, of the National Oceanography Centre in Southampton.

        The submarine dubbed Boaty McBoatface returns from its voyage. (PA)

The data was collected as part of a joint project involving the University of Southampton, the National Oceanography Centre, the British Antarctic Survey, Woods Hole Oceanographic Institution in Massachusetts and Princeton University.

"This study is a great example of how exciting new technology such as the unmanned submarine Boaty McBoatface can be used along with ship-based measurements and cutting-edge ocean models to discover and explain previously unknown processes affecting heat transport within the ocean," said Dr Povl Abrahamsen, of the British Antarctic Survey.

The robotic submersible was given the name originally chosen for a polar research ship by irreverent contestants in a public competition.

Embarrassed officials decided to ignore the popular vote and instead named the vessel the RRS Sir David Attenborough in honour of the veteran broadcaster.

A storm of protest on Twitter led to a compromise that allowed the Boaty McBoatface name to live on.

The submarine is able to collect significant amounts of previously unattainable data due to the way it can manoeuvre at great depths.

https://www.msn.com/en-gb/news/environment/boaty-mcboatface-makes-major-climate-change-discovery-on-debut-voyage/ar-AAD3f59?ocid=chromentp

 

[CaaC (John)+]

Greenland Ice Sheet: 'More than 50 hidden lakes' detected

By Jonathan Amos

BBC Science Correspondent

Scientists have identified more than 50 new lakes of liquid water lying under the Greenland Ice Sheet.

Only four had previously been detected.

Antarctica hides some 470 lakes beneath its ice but this latest UK/US study proves the northern polar region also has its share.

They are nothing like as big, however. The largest down south, Lake Vostok, is 250km long. The biggest subglacial lake in Greenland is just 6km long.

Extensive areas of water can pool under a kilometres-thick ice sheet for a number of reasons.

Pressure from above and geothermal heat from below can maintain a liquid; surface meltwaters will also drain to the bed and collect in hollows.

Researchers are interested in finding such lakes because they say something about the hydrology (water network) underlying an ice sheet and the way it moves.

Water acts as a lubricant, and as the world warms, modelling how quickly ice might slide towards the ocean will inform projections of future sea-level rise.

Greenland's ice would increase global ocean height by 7m if it were all to melt.

Jade Bowling from Lancaster University manually inspected 570,000km of ice-penetrating radar data gathered by Nasa's IceBridge programme in Greenland.

The US space agency has regularly flown an instrumented plane back and forth across the ice sheet to map its internal layers and the shape of the bedrock. Liquid water has a telltale backscatter pattern in radar data.

The PhD student identified 54 candidate lakes in this search. "In contrast to Antarctic subglacial lakes, which are typically clustered around (interior) ice divides, these new Greenlandic lakes are mostly found towards the margin of the ice sheet, under relatively slow-moving ice and are mostly stable," she told BBC News.

"They are also much smaller than those in Antarctica (1.4km average length compared to 11km)."

As well as the 54 radar lakes, a further two candidates were found by looking for sharp height changes in the new ArcticDEM dataset.

This elevation model was built from very high-resolution satellite photos and Ms Bowling sees a couple of places where the ice surface has slumped, presumably because an underlying lake has drained away.

"These 'active' lakes that fill and drain, making the ice lift up and down, seem to be rare," said co-author Dr Stephen Livingstone. "But we speculate that the signal of active subglacial lakes near the margin of the ice sheet may actually be being lost because this is where a lot of surface meltwater gets down to the bed.

"This water may be flushing out the lakes on a seasonal basis by making very efficient channels. The margins may just be a very dynamic area."

In Antarctica, a number of lakes, including Vostok, have been the target for scientific drilling.

The thought is that some of the oldest, most stable lakes will hold ancient organisms that have been trapped in place from when the ice sheet formed.

The chemistry of the water and the nature of the sediments should also provide valuable insights on past environmental conditions.

Prof Martin Siegert at Imperial College London led an effort to try to drill into Antarctica's subglacial Lake Ellsworth.

He commented to BBC News: "Since the ice sheet is likely to have changed massively in the last ice age cycle, these Greenlandic lakes are unlikely to be ‘very’ old. Hence, the types of questions you might ask from Lake Vostok/Ellsworth will be different from what you might accomplish by drilling into a Greenland lake.

"As the authors say, these are just candidate lakes and more geophysics is needed to determine whether they would be interesting to drill (check for water depth, topographic setting, basal sediment).

"So, an analysis on which lakes look best from an exploration perspective seems a logical next step. Then, if the science return looks strong enough, an exploration mission could well follow."

Ms Bowling and co-workers have published their analysis of Greenland's subglacial lakes in the journal Nature Communications.

https://www.bbc.co.uk/news/science-environment-48773778

[CaaC (John)+]

This volcano just erupted after nearly a century of silence. Astronauts captured the breathtaking scene from 254 miles above.

Matthew Cappucci

Watching a volcano erupt would be cool. But having a front-row seat 254 miles above the volcano? That would be a view.

Astronauts aboard the International Space Station captured the breathtaking scene Saturday showing the vigorous eruption of the Raikoke volcano.

Raikoke is an uninhabited island along the Kuril chain, a necklace of narrow strip islands draped 500 miles from northern Japan to northeast Russia. Formerly owned by Japan, the volcanic island — which occupies an area less than two square miles — is under the control of Russia, and has been since World War II.

The aerial view offers a perspective seldom seen during major eruptions. Like a thunderstorm, a mushroom cloud blossoms over the volcano, where ash is catapulted into the sky with explosive force. The updraft is so strong in the middle that it “outruns” the plume’s periphery, making the edges curl down before becoming entrained in the rising cloud again. During Saturday’s eruption, the plume may have rocketed up more than 50,000 feet (10 miles)

It’s easy to guess which way the winds were blowing by looking at the photograph. A more diffuse, expansive sheet of ash clouds lingers downwind, transported by strong upper-level winds over the Sea of Okhotsk. Volcanic ash is heavy in silicates, which have a melting temperature close to 2,000 degrees. Many commercial aircraft engines operate at temperatures well over 2,500 degrees — meaning the dustlike particles would melt and stick to vital mechanics in the plane. That can cause them to “choke” an engine, making volcanic ash clouds dangerous for aviation.

Volcanic ash can’t be seen on traditional radar or the forward-looking radar in the nose of most jets. That makes forecasting it vitally important. Visibly, ash clouds are easy to spot from far away, so they’re simple to avoid during the daytime. But if a plane was to enter an ash cloud at night, it would have one telltale sign: electricity arcing across the windshield.

Volcanic ash clouds are highly electrified. If a plane flew into one, so much charge would build up that discharges of St. Elmo’s Fire would leap across the windshield like small lightning bolts.

Raikoke’s ash cloud was no exception, with hundreds of lightning bolts leaping from the supercharged ash above. Atmospheric scientists refer to this lightning barrage as a “dirty thunderstorm.”

The intensity and frequency of volcanic lightning discharges can offer insight about how robust the eruption was. Lightning activity peaked during four main periods, suggesting Raikoke’s eruption was several individual bursts. That’s also evident in the shape of the clouds: notice the downwind anvil is already there while a new plume immediately goes over the volcano.

Near the base of the plume, a collar of white, puffy clouds can be seen. That’s water vapour — not ash. The enormous amount of gas and other materials released by the volcano probably contained water vapour, with the temperature contrast between the fiery plume and the air around it causing condensation.

What would it be like under this cloud? First, you’d see the amber, sand-coloured anvil approaching. There might be an ominous display of mammatus clouds, the iconic pouch-like bags that hang beneath foreboding storms that usually are a sign of turbulence in the atmosphere. The sun would appear a creepy orange colour until it disappeared. Lightning would crackle, crawling along the anvil; the gases in the atmosphere would make it a neon-purple colour. Bolts would hit the ground as far as 60 miles away.

Closer to the plume, you might get a spattering of small pebbles raining down, possibly with a thin glaze of ice around them, like rocky hailstones. Depending on the temperature of the atmosphere, deadly gas and ash might make it down toward the surface. A number of whirlwinds and waterspouts would likely also be dancing.

Saturday’s eruption marks Raikoke’s first since 1924. Before that, a “catastrophic” eruption occurred in 1778. In the meantime, there’s no telling what Raikoke’s next move will be.

https://www.msn.com/en-gb/news/world/this-volcano-just-erupted-after-nearly-a-century-of-silence-astronauts-captured-the-breathtaking-scene-from-254-miles-above/ar-AADuBrp?ocid=chromentp

[CaaC (John)+]

Climate change: Antarctic Peninsula 'can still avoid irreversible change'

Even if global warming can be kept to a 1.5-degree Celsius rise from pre-industrial times, the Antarctic Peninsula is set for some big changes.

This is the assessment of an expert panel of scientists.

The group says reaching the threshold will likely result in a 50-150% increase in the number of days a year the frozen peninsula spends above zero.

But although this means more melting, the team also stresses the "benefits" that come from not breaching 1.5C.

Keeping below this figure should allow the peninsula to hang on to its remaining ice shelves, they argue.

That's important because these floating platforms of ice that fringe the long spine of mountainous land work to hold back glaciers, preventing them from dumping more ice into the ocean and rising sea-levels.

Recent decades have seen a dozen or so shelves either disintegrate or lose significant volume, as the peninsula has warmed more than twice as fast as the rest of the planet.

"A 1.5-degree world" increases the likelihood of thinning and iceberg production, according to the panel. However, it's possible the largest ice shelves can still retain sufficient integrity to avoid further catastrophic failures.

"Under 1.5, we don't expect ice shelves to be lost - but under more warming, they look far more vulnerable with consequences for sea-level and other impacts," explained Prof Martin Siegert from Imperial College London, UK.

"The 'benefits' of 1.5 need to be explained - and we're trying to explain that while the peninsula is locked into change. It's still possible to avoid severe problems that would change the peninsula beyond recognition and without historic precedence," he told BBC News.

• Glaciers to honour 'satellite heroes'
• Antarctic instability 'is spreading'

Prof Siegert and colleagues from UK and US institutions have written a briefing note that is being presented to an Antarctic Treaty meeting on Tuesday by the British Foreign Office.

It sets out the consequences for the peninsula of a further half-degree rise in global temperature (the world has already warmed by about 1C since 1850). 1.5C is the preferred target to limit warming set out in the Paris climate agreement.

The scientists stress that any rise will almost certainly be amplified in the polar regions.

The extra half a degree globally is likely to translate in the Antarctic Peninsula to an increase of 1-2C in winter and 0.5-1.0C in summer.

Co-author Prof David Vaughan, the director of science at the British Antarctic Survey, commented: "Local warming in the Antarctic Peninsula over the last few decades has been higher than almost anywhere else in the Southern Hemisphere.

"If similar high levels of local warming occur in the future, magnifying rates of change on the Antarctic Peninsula, then summer melt will move south and ice shelves that have not yet shown any progressive retreat or collapse could be threatened.

"Larsen-C is probably the most vulnerable on the east coast and, if we're unlucky, could be impacted in the next couple of decades," he told BBC News.

One mechanism that may mitigate the impact on ice shelves is if ponding meltwater can form efficient rivers that drain across and away from the platforms, rather than filtering down through crevasses.

It's the downward movement of meltwater that can open up fissures, driving them through to the base of a shelf.

This process, known as hydrofracturing, will weaken the structure. But there are examples where the meltwater finds an easier route to the sea via a network of channels cut in the top of a shelf.

https://www.bbc.co.uk/news/science-environment-48840528

 

 

Edited July 2, 2019 by CaaC (John)
Spelling corrections

[CaaC (John)+]

Remote Mount Michael volcano hosts persistent lava lake

Satellite pictures confirm there is a persistent lava lake inside the crater of a remote British Overseas Territory (BOT) volcano.

Few enduring lava lakes are known globally; the one at Mount Michael on Saunders Island in the South Atlantic may be only the eighth such example.

The 990m-high stratovolcano's setting makes it extremely difficult to climb.

Pictures taken from space are really, therefore, the only way of looking inside the opening at the summit.

Orbiting sensors from as far back as the 1990s have detected heat anomalies in the crater.

But it has taken the most modern satellites to resolve the crater floor and to verify the presence of the lake.

• Satellites show the extent of volcano collapse
• Space project to monitor all volcanoes

Scientists from University College London and the British Antarctic Survey (BAS) assessed data from 2003 to 2018.

This information indicates a continuous molten lava feature that is between 90m and 215m wide, with a temperature of around 1,000C.

There are some 1,500 active volcanoes on the Earth's land surface but it is extremely rare for them to maintain a broiling liquid mass in their craters.

Saunders Island is part of the South Georgia and South Sandwich Islands British Overseas Territory.

"The island has been visited on numerous occasions, but no-one has ever climbed the mountain," commented Dr Peter Fretwell from BAS.

"If you look at the imagery you can see why: the peak is surrounded by a huge snow-mushroom, extremely soft snow with an icing sugar like consistency, probably caused by the continual venting of steam by the volcano.

"You cannot walk over this, you would have to dig through it, but taking the time to do this on such an active volcano would be dangerous," he told BBC News.

A key question is how Mount Michael is able to maintain the lake. Why doesn't it solidify from time to time?

BAS colleague Dr Alex Burton-Johnson said this had been a puzzle for a long time.

"Our understanding is that volcanoes emit two types of material: rock (in the form of lava, pumice, and volcanic ash) and what we call volatiles (hot gases, including water, carbon dioxide and sulphur dioxide. Hence the white clouds (the water) and the smell (the sulphur)),' he explained.

"Both of these are incredibly hot, transferring heat from the depths of the mantle. For most volcanoes, the rock outpourings result in lava flows, but for a lava lake to stay molten but not overflow, the flow of lava from depth must be low, and instead, the majority of the expelled matter and the source of the heat must be from the gases.

"This implies that the lava beneath the volcano is very gas-rich."

This requirement for a constant flux of heat purely from the emitted gases might explain why a cloud of vapour emissions is seen always to be coming from the volcano, Dr Burton-Johnson said. This is something that has been noticed right back to the first recorded documentation of the island in 1820 by Russian explorer Fabian Gottlieb von Bellingshausen.

"In contrast, observations of eruptive activity are rather rare," the geologist added.

The UCL/BAS team reports its assessment of Mount Michael's lava lake in the journal Volcanology and Geothermal Research.

Lava lakes are also known at Nyiragongo volcano, DR Congo; Erta Ale volcano, Ethiopia; Mount Erebus, Antarctica; Mount Yasur, Vanuatu; Ambrym volcanic island, Vanuatu; Kilauea, Hawaii; and Masaya volcano, Nicaragua.

https://www.bbc.co.uk/news/science-environment-48852670

[CaaC (John)+]

Stunning Northern Lights in Iceland

VIDEO

[CaaC (John)+]

First image of Einstein's 'spooky' particle entanglement

Scientists have captured the first ever image of a phenomenon which Albert Einstein once described as "spooky action at a distance".

The photo shows a strong form of quantum entanglement, where two particles interact and share their physical states for an instant.

It occurs no matter how great the distance between the particles is.

The connection is known as Bell entanglement and underpins the field of quantum mechanics.

Paul-Antoine Moreau, of the University of Glasgow's School of Physics and Astronomy, said the image was "an elegant demonstration of a fundamental property of nature".

He added: "It's an exciting result which could be used to advance the emerging field of quantum computing and lead to new types of imaging."

Einstein described quantum mechanics as "spooky" because of the instantaneousness of the apparent remote interaction between two entangled particles.

The interaction also seemed incompatible with elements of his special theory of relativity.

Scientist Sir John Bell later formalised the concept by describing in detail a strong form of entanglement exhibiting the feature.

Bell entanglement is now harnessed in practical applications such as quantum computing and cryptography.

However, it has never before been captured in a single image.

The team of physicists from the University of Glasgow devised a system that fired a stream of entangled photons from a quantum source of light at "non-conventional" objects.

This was displayed on liquid-crystal materials which change the phase of the photons as they pass through.

https://www.bbc.co.uk/news/uk-scotland-glasgow-west-48971538

[CaaC (John)+]

Lake discovered 11,000ft high in the Alps, in 'truly alarming' sign of climate change

Adam Forrest

A mountaineer has captured the formation of an “alarming” lake high in the French Alps after glacial snow melted in the intense heatwave that gripped central Europe in late June.

Bryan Mestre was shocked to discover the large pool of water at an altitude of 11,100ft (3,400m) in the Mont Blanc mountain range – claiming the unusual sight was a worrying sign.

Scientists have warned that heatwaves in Europe are becoming increasingly frequent, with the intense temperatures linked to climate change.

“Time to sound the alarm,” said Mr Mestre. “Only 10 days of extreme heat were enough to collapse, melt and form a lake at the base of the Dent du Géant and the Aiguilles Marbrées.”

He added: “This is truly alarming … glaciers all over the world are melting at an exponential speed.”

Sharing the image on Instagram, the French rock climber said he took the photo on 28 June – only 10 days after fellow mountaineer Paul Todhunter captured the same area covered in snow.

“Needless to say, the lake was a real surprise,” Mr Mestre told the IFLScience website.

“It’s located in the 3,400 to 3,500-meter area. You’re supposed to find ice and snow at this altitude, not liquid water. Most of the time when we stay for a day at this altitude, the water in our water bottles starts freezing.”

“I have been up there a fair amount of times, in June, July and even August, and I have never seen liquid water up there,” he added.

Glaciologist Ludovic Ravanel previously noticed a lake appearing high in the French Alps in 2015 and linked its formation to global warming.

According to the EU’s Copernicus Climate Change Service (C3S), last month was the hottest June ever recorded on Earth.

Data released by the satellite agency showed Europe’s average temperatures were more than 2C above normal, and temperatures were between 6C and 10C above normal over most of France, Germany and northern Spain during the final days of the month.

https://www.msn.com/en-gb/news/environment/lake-discovered-11000ft-high-in-the-alps-in-truly-alarming-sign-of-climate-change/ar-AAEpFng?MSCC=1563365161&ocid=chromentp

[CaaC (John)+]

Hawaii TMT: Desecrating sacred land or finding new frontiers?

Rifts over a dormant volcano in Hawaii have resurfaced in recent days, pitting the state's culture and history against its ambitions.

Plans for a powerful new telescope near the summit of the Mauna Kea volcano could bring in hundreds of jobs and boost science and the economy. But some native Hawaiians insist the site is sacred and that the long-planned construction should not go ahead.

Last week, protesters blocked access to the building site on Mauna Kea, the tallest mountain in the world when measured from its underwater base. At least 33 people were arrested, given citations and released.

Hawaii's governor has issued an "emergency proclamation" that increases powers to break up the blockade but said he wanted to find a "peaceful and satisfactory" solution for both sides.

Here, some of the people at the centre of the debate explain what Mauna Kea and the Thirty Meter Telescope (TMT) project mean to them.

For: 'It might lead us to alien life'

The $1.4bn (£1.1bn) TMT could help answer one of mankind's biggest questions: is there life on other planets? That's according to Roy Gal, an associate astronomer at the University of Hawaii.

"We will, for the first time, be able to make measurements of the atmospheres of Earth-size planets in the habitable zone around other stars," he said. "We will see if those planets' atmospheres have water and molecules that could be due to biological activity.

"I study galaxies and how they evolve over time in different kinds of environments in the universe. The TMT would allow us to push these studies to fainter galaxies - ones that are further away and therefore we see them a longer time ago. It would allow us to paint a more complete life story of galaxies, from infancy to adulthood.

"With current telescopes, it's like studying humans starting when they're teenagers. The TMT would allow us to see them as infants."

Roy said Mauna Kea had the ideal conditions for viewing the cosmos and that telescopes there had already contributed to major findings, including the observation that the expansion of the universe was accelerating.

"Any new telescope capability we get, we always, always without fail to find something new that we didn't expect," he said.

Against: 'It is our temple'

The mountain is a temple to native Hawaiians, offering a connection between "creation and creator", said Kealoha Pisciotta, president of the Mauna Kea Anaina Hou, one of the main groups opposing the TMT.

"It contains some of our highest born and most revered ancestors. It is a symbol of peace and aloha", she said.

The summit, considered to be in the realm of gods, "is reserved for very special things, unique things, things done by the chiefs and chiefesses, things done by priests and spiritual leaders. It is not just a general place for man."

A number of telescopes have already been constructed on top of Mauna Kea, and Kealoha and others say they do not believe promises that the TMT will be the last.

"We allowed astronomy to have a place on the Mauna Kea but they continue to ask for more and more and more, and we have to say no at this point. Because when we say yes it means saying yes to the destruction of our endangered lands," she said.

Building on Mauna Kea was like "destroying the inside of a church because within the whole landscape are religious things", Kealoha added.

"All these man-made structures are right in the middle of our environment of belief."

She said that the planned construction of the TMT was a sign of economics taking precedence over human rights and that, in addition to it being a sacred landscape, the mountain was an important environmental site and source of water.

Kealoha urged the groups behind the TMT to consider moving it to a backup site in the Canary Islands and said the protests would continue until this happened.

"Human life is more important than our sense of discovery. Sense of discovery is good and all but what does it mean when you're willing to let people get hurt?" she asked.

For: 'Astronomy helps me feel connected to my culture'

The volcano is a "sacred and special place that must be treated with the utmost respect", said Alexis Acohido, a native Hawaiian who has worked for more than four years at existing observatories on Mauna Kea.

"I support the Thirty Meter Telescope project because of the educational opportunities it can provide," she said.

"Astronomy is one of the ways I feel most connected to my culture. Hawaiians are incredible scientists, engineers, and overall problem solvers. The way that they were able to navigate the vast Pacific by observing the winds, waves, and stars is inspiring to me.

"Itʻs my belief that the science we are doing on Mauna Kea is an extension of that legacy, and makes me proud to call myself Hawaiian."

Alexis said the TMT would not disrupt culturally significant sites on the mountain.

"To me, TMT has been pono" - a Hawaiian term meaning proper or morally correct - "throughout this whole process. That demonstrates to me that they are willing to be responsible stewards on Mauna Kea."

Against: 'Not an opposition to science'

"The Mauna Kea is recognised as the home of several deities all of whom are associated with water," said Noelani Goodyear-Kaopua, a professor of political science focusing on indigenous and native Hawaiian politics. "They are embodied in the forms of precipitation that surround the mountain."

The mountain is part of Hawaii's "ceded lands", which once belonged to the Hawaiian kingdom and are now held in trust by the state. The land on which the telescopes are built is leased to the University of Hawaii, where Noelani works.

She said the division over the project had trickled down to the university itself, as she questioned the research ethics of the project.

Hundreds of scientists and astronomers, including many from institutions linked to the project, have also condemned the "criminalisation" of people opposing the TMT.

Noelani stressed that the protests against the TMT were not "an opposition to science".

"It's really an opposition to industrial development and the destruction of land and natural resources and precious and fragile ecology," she said.

"We have stood by while too many of our precious resources and environment have been degraded and harmed and we're not going to stand for it any more."

For: 'The mountain is big enough for everyone'

Kalepa Baybayan, a native Hawaiian navigator, said Mauna Kea had long served as a "beacon" that had led him home from journeys at sea.

"My relationship with the mountain comes from the experiences that I've had voyaging across the ocean and using the stars as a means to help create a guidance system for ourselves," he said. "In my travels, in navigating to Hawaii without any instruments, we usually start with Mauna Kea.

"My appreciation for astronomy comes from a totally cultural lens," he added.

"Our job as humanity is to ensure that our planet lives a long, full life. But sometime in the very, very distant future, life on this planet will come to an end and astronomy looks at the very beginnings of the universe and where we're going.

"The reason that I support astronomy is because I want to know what options there are for humanity. What I don't want is for humanity to slide backwards into a scientific dark age all over again," Kalepa said.

Kalepa argued that his ancestors would have approved of the TMT as a "portal to the universe".

"I just think that people have forgotten the fact that as early oceanic explorers, we left the safety of the shores and discovered the stars through sailing our canoes across thousands of miles of the ocean," he said.

He also said there would be economic benefits to the TMT, including rent payments and jobs. "There is enough room on the mountain for everyone. What people have to learn is to share."

Against: 'Hawaii is its culture'

The mountain is central to Hawaii's identity, said Theresa Keohunani Taber, an opponent of the TMT project who helps to raise support for the movement on social media.

"Hawaiian culture and Hawaiian language and Hawaiian resources and Hawaiian people are what Hawaii is. If you start eliminating that narrative then there is no Hawaii," she said.

Theresa first became involved in protecting Mauna Kea after moving to Hawaii from the mainland US and attending a meeting of hundreds of opponents of a separate project on the mountain in 2002.

"It was my very first introduction to how important, how impactful the Mauna Kea has been, not only to our state but to our culture and history as Hawaiians," she said. "That was a very powerful moment."

She said she and other Hawaiians "felt the pain" of people in France when a fire engulfed the Notre-Dame cathedral in April.

"We wouldn't wish that on any people; to lose their place of worship or the place that connects them to the higher power that they believe in. Mauna Kea and all mountains, all sacred places, are just as reverent, just as important as a church or a mosque."

https://www.bbc.co.uk/news/world-us-canada-49082156

[CaaC (John)+]

AI system 'should be recognised as an inventor'

An artificial intelligence system should be recognised as the inventor of two ideas in patents filed on its behalf, a team of academics says.

The AI has designed interlocking food containers that are easy for robots to grasp and a warning light that flashes in a rhythm that is hard to ignore.

Patents offices insist innovations are attributed to humans - to avoid legal complications that would arise if corporate inventorship were recognised.

The academics say this is "outdated".

And it could see patent offices refusing to assign any intellectual property rights for AI-generated creations.

As a result, two professors from the University of Surrey have teamed up with the Missouri-based inventor of Dabus AI to file patents in the system's name with the relevant authorities in the UK, Europe and US.

'Inventive act'

Dabus was previously best known for creating surreal art thanks to the way "noise" is mixed into its neural networks to help generate unusual ideas.

Unlike some machine-learning systems, Dabus has not been trained to solve particular problems.

Instead, it seeks to devise and develop new ideas - "what is traditionally considered the mental part of the inventive act", according to creator Stephen Thaler

The first patent describes a food container that uses fractal designs to create pits and bulges in its sides. One benefit is that several containers can be fitted together more tightly to help them be transported safely. Another is that it should be easier for robotic arms to pick them up and grip them.

The second describes a lamp designed to flicker in a rhythm in a rhythm mimicking patterns of neural activity that accompany the formation of ideas, making it more difficult to ignore.

Law professor Ryan Abbott told BBC News: "These days, you commonly have AIs writing books and taking pictures - but if you don't have a traditional author, you cannot get copyright protection in the US.

"So with patents, a patent office might say, 'If you don't have someone who traditionally meets human-inventorship criteria, there is nothing you can get a patent on.'

"In which case, if AI is going to be how we're inventing things in the future, the whole intellectual property system will fail to work."

Instead, he suggested, an AI should be recognised as being the inventor and whoever the AI belonged to should be the patent's owner, unless they sold it on.

However, Prof Abbott acknowledged lawmakers might need to get involved to settle the matter and that it could take until the mid-2020s to resolve the issue.

A spokeswoman for the European Patent Office indicated that it would be a complex matter.

"It is a global consensus that an inventor can only be a person who makes a contribution to the invention's conception in the form of devising an idea or a plan in the mind," she explained.

"The current state of technological development suggests that, for the foreseeable future, AI is... a tool used by a human inventor.

"Any change... [would] have implications reaching far beyond patent law, ie to authors' rights under copyright laws, civil liability and data protection.

"The EPO is, of course, aware of discussions in interested circles and the wider public about whether AI could qualify as an inventor."

The  UK's Patents Act 1977  currently requires an inventor to be a person, but the Intellectual Property Office is aware of the issue.

"The government believes that AI technology could increase the UK's GDP by 10% in the next decade, and the IPO is focused on responding to the challenges that come with this growth," said a spokeswoman.

https://www.bbc.co.uk/news/technology-49191645

[CaaC (John)+]

Scientists Are Creating a 3D Model of an 18th-Century ‘Vampire Witch’ Who Was Tortured to Death

Ellen Gutoskey

In 2014, archaeologists uncovered a skeleton in Kamień Pomorski, Poland, with a brick wedged in its mouth and stakes driven through its legs. They believed the man was put to death in the 18th century because townspeople thought he was a vampire.

Now, genetic and forensic analysis has shown that the vampire burial site didn't contain a man at all: It was a 5-foot-6-inch, blue-eyed, blonde woman who was at least 65 years old when she died. Newsweek reports that scientists at the Pomeranian Medical University in Szczecin, Poland are now making a 3D computer model of the woman’s skull, which they plan to use to recreate what her face looked like.

The Forensic Genetics Unit at the university will then build her face on a physical model from layers of plastic material and reveal it to the public within the next few months. Andrzej Ossowski, the head of the unit, told the website Science in Poland that he hopes a museum might display the rendering. “We want to show that with the help of modern methods, we are able to replace skeletons that are very common in museums with 3D models based on research,” he said.

He said that townspeople may have killed the woman because they thought she was a witch, and they gave her an “anti-vampiric” burial to prevent her from rising from her grave à la Nosferatu. The brick in her mouth was meant to weigh her down—in other burials a sickle might have been placed across the neck of the body, which would slit the revenant's throat should it try to rise.

We often think of Salem when it comes to witch trials, but they were common throughout Europe before the 19th century, and archaeologists have discovered “anti-vampiric” graves in Poland, Bulgaria, and Italy. Wondering if you might have qualified as a witch during the 17th-century period of Puritan paranoia? Find out here.

https://www.msn.com/en-gb/news/offbeat/scientists-are-creating-a-3d-model-of-an-18th-century-vampire-witch-who-was-tortured-to-death/ar-AAFqz2C

Edited August 7, 2019 by CaaC (John)

[CaaC (John)+]

@nudge, your thoughts, please, 

 

 Bill Gates backing plan to stop climate change by blocking out the sun

It sounds like a wacky idea out of science fiction - but it’s backed in part by billionaire Microsoft founder Bill Gates and top scientists from Harvard.

The researchers believe that a fleet of specially designed aircraft could spray sulfate particles into the lower stratosphere to cool down our planet and offset the effects of climate change.

A test of the technology has been proposed for this year, the Daily Mail reports, with the Stratospheric Controlled Perturbation Experiment (SCoPEx) seeing a bag of carbonate dust released into the atmosphere 12 miles up.

If that experiment proves successful, the researchers will move on to releasing the dust from planes.

The researchers suggest that jets flying 12 miles up would complete over 60,000 missions in 15 years, starting with a fleet of eight and moving up to 100 planes.

At present, there are no aircraft capable of doing this, so they would need to be developed.

The Harvard researchers have claimed that (if it were launched this year), it would cost about $3.5 billion (£2.74 billion),, plus $2.25 billion (£1.76 billion) per year.

The researchers said last year, ‘Dozens of countries would have both the expertise and the money to launch such a program.

‘Around 50 countries have military budgets greater than $3 billion, with 30 greater than $6 billion.’

The idea of ‘solar geoengineering’ or solar radiation management (SRM) is controversial, mimicking the world-chilling effects of huge volcanic eruptions.

Some scientists have suggested that such technology could be used a ‘stop-gap’ to reduce temperatures while measures to limit CO2 emissions are put in place.

But others have suggested that when the SRM was withdrawn, it could lead to rapid global warming in a phenomenon known as ‘termination shock’.

https://www.msn.com/en-gb/money/technology/bill-gates-backing-plan-to-stop-climate-change-by-blocking-out-the-sun/ar-AAFKQVN?li=BBoPWjQ

 

Edited August 13, 2019 by CaaC (John)

[nudge+]

1 hour ago, CaaC (John) said:

@nudge, your thoughts, please, 

A risky and controversial approach that focuses on treating the symptom instead of the cause and can do even more harm. I'd love to see how the study evaluates the potentially severe side effects such as decline in crop yields, changes in weather/precipitation patterns, acid rains and ocean acidification, changes in entire ecosystems and so on.

On the positive side, that's how quite a few sci-fi dystopian movies started  

[CaaC (John)+]

What is 'blobology' and how is it transforming biology?

Spectacularly detailed videos from an advanced microscope are sparking a biology "revolution", scientists say.

The technique was once termed "blobology" because its images were so indistinct.

But now, it is being used to create videos of the body's inner-workings at a hitherto unseen level of detail.

This new view inside the body is likely to accelerate the development of more effective drugs for dementia and infection.

According to Dr Peter Rosenthal, of the Francis Crick Institute in London, there is a "growing buzz" about the potential of the technology.

"It is the hottest new approach in biological research at the moment," he told BBC News.

"It's been described as a 'resolution revolution'. There is an exponential growth in the number of new images and 3D maps being produced and researchers are clamouring to be trained how to do it."

FULL REPORT

Edited August 22, 2019 by CaaC (John)
Spacing correction

[CaaC (John)+]

Earth's inner core is doing something weird

On September 27, 1971, a nuclear bomb exploded on Russia’s Novaya Zemlya islands. The powerful blast sent waves rippling so deep inside Earth they ricocheted off the inner core, pinging an array of hundreds of mechanical ears some 4,000 miles away in the Montana wilderness. Three years later, that array picked up a signal when a second bomb exploded at nearly the same spot.

This pair of nuclear explosions were part of hundreds of tests detonated during the throes of Cold War fervour. Now, the records of these wiggles are making waves among geologists: They have helped scientists calculate one of the most precise estimates yet of how fast the planet’s inner core is spinning.

Surface-dwellers know that Earth spins on its axis once about every 24 hours. But the inner core is a roughly moon-sized ball of iron floating within an ocean of molten metal, which means it is free to turn independently from our planet’s large-scale spin, a phenomenon known as super-rotation. And how fast it’s going has been hotly debated.

Capitalizing on the zigzagged signals from those decades-old nuclear explosions, John Vidale, a seismologist at the University of Southern California, now has the latest estimate for this rate. In a recent study published in Geophysical Research Letters, he reports that the inner core likely inches along just faster than Earth’s surface. If his rate’s right, it means that if you stood on a spot at the Equator for one year, the part of the inner core that was previously beneath you would wind up under a spot 4.8 miles away.

“It’s a careful, good piece of work,” says Paul Richards, a seismologist at Columbia University who was a co-author on a 1996 study that first proposed super-rotation of the inner core. “Something is changing down there.”

Better understanding the history and current dynamics of the iron blob nestled within our planet could yield more clues to the processes charging and stabilizing our magnetic field—a geologic force field that protects our world from various kinds of harmful radiation. We don’t yet fully understand how this magnetic dynamo works, but scientists strongly suspect it’s tied to the mysterious motions deep inside the planet. (Learn what really happens when Earth's magnetic field flips.)

“The Earth is this extreme natural lab,” says Elizabeth Day, a deep-earth seismologist at Imperial College London who was not part of the work. Thousands of miles below our feet, pressures are crushing and temperatures are searing. “We can’t easily reproduce all of those in an actual laboratory. But if we can peer into the Earth, we get a bit of insight into this really extreme set of conditions.”

The new work is just one of many attempts to figure out the core’s rate of super-rotation but offers one of the slowest rates for super-rotation yet suggested. Still, the differences between these studies is not necessarily a bad thing, Day says.

“It doesn’t mean anyone is wrong,” she says. “It just means everyone is looking at slightly different things.”

Core conundrum

SLIDES - 1/12

Previous work, including the paper Richards coauthored, used various properties of earthquake waves travelling through the planet to deliver their estimates for the inner core’s super-rotation, with several sitting around a few tenths of a degree a year. Such measurements aren’t easy to make, though, and the resolution of many of these analyses were low. But unlike earthquakes, which send out juddering waves, nuclear explosions provide a clean signal to work with.

“This is like Earth just got hit with a hammer,” Day says.

The issue was extracting the data, which were encoded on nine-track tapes by the Large Aperture Seismic Array in Montana. By the 1990s, the tapes had made their way to the Albuquerque Seismological Laboratory, where Paul Earle, then a graduate student at Scripps Institute of Oceanography, was tasked with extracting the echoes of Soviet nuclear tests from the deteriorating tapes.

Video: Earth 101

Earle spent two weeks in a room full of boxes laden with discs sporting cryptic labels. Many of the tapes were worn, their magnetic information lost to time. Roughly one in 10 couldn’t be read by a tape-player, says Earle, who is now a seismologist with the U.S. Geological Survey.

But the effort was worth it. Earle, Vidale, and Doug Dodge of Lawrence Livermore National Laboratory used the scattered waves from these nuclear explosions to peer into the planet’s core. By comparing the fingerprint of waves scattered back from explosions at nearly the same location in 1971 and 1974, the team could calculate how much faster the inner core turned relative to the rest of the planet. The process is similar to tracking a moving aeroplane using radar, Richards notes.

Their initial results, published in a 2000 Nature study, pointed to a rotation rate of 0.15 degrees a year. Vidale then shifted gears and didn’t give the inner core much thought for nearly 15 years.

Digging deeper

That changed in December 2018, when he walked through the bustling poster hall at the American Geophysical Union’s annual conference. There, Vidale spotted the work of Jiayuan Yao, now a research fellow in geophysics at Nanyang Technological University.

Yao had combed through tens of thousands of earthquakes in search of pairs that strike at different times in precisely the same location. By comparing the seismic waves that grazed the inner core from 40 of these geologic twins, he hoped to suss out the mysteries held deep in our planet.

“That is really great data,” Vidale recalls thinking. However, Yao’s interpretation of the data didn’t point toward super-rotation and instead suggested something else seemed to be going on.

Intrigued by this conundrum, Vidale turned back to his dataset on the nuclear explosions, but with the original analysis codes nowhere to be found, he had to start from scratch, digging even deeper into the Cold War-era ripples with an updated method.

His resulting analysis still yielded super-rotation, but it was both slower and more precise than previous estimates, pointing instead toward the newly described rate of 0.07 degree a year between 1971 and 1974.

Certain uncertainty

But while other scientists praise the thoroughness of Vidale’s latest work, the debate seems far from settled.

Yao and his colleagues recently published an intriguing alternative explanation using his data from twin earthquakes. Perhaps, they posit, the inner core is actually rotating at the same speed as the rest of our planet, and the apparent difference could instead be explained by the inner core having a jagged surface that shifts over time, with mountains rising or canyons cutting into the iron orb. (Read about ‘mountains’ taller than Everest that lurk deep inside Earth.)

Vidale finds that analysis intriguing, but while he agrees that there may be more than super-rotation in the mix, he’s sceptical of Yao’s precise explanation.

One possibility, Richards argues, is that blob itself is warping over time.

“It’s like when you throw a pizza up in the air,” he says. “It’s spinning, but it’s flopping around. It’s deforming as it rotates.”

It’s also possible that the rate of inner core rotation varies over time, adds Xiaodong Song, a deep-earth seismologist at the University of Illinois who co-authored the 1996 study first documenting inner core rotation. While Vidale’s latest rate is robust, it’s limited to a single time period, so further confirmation is necessary, he says via email.

“It’s so hard to do these studies,” says Jessica Irving, a deep-earth seismologist at Princeton University. “Every scrap of data becomes valuable, and unfortunately there just aren’t very many scraps of data.” Perhaps more definitive answers may be on the horizon. Analyses are getting better, and data are accruing on seismometers around the world that are constantly listening for our planet’s every tremble.

Solving the puzzle of the inner core, Yao says, “doesn’t need to take another decade.”

https://www.msn.com/en-gb/news/spotlight/earths-inner-core-is-doing-something-weird/ar-AAG2cmq?ocid=chromentp

[CaaC (John)+]

'Mission Jurassic' fossil dinosaur dig closes for winter

Three full truckloads of dinosaur fossils were shipped out of the "Mission Jurassic" dig site in North Wyoming as scientists brought the 80-day excavation season to an end.

The specimens included skeletal parts from giant herbivorous sauropods and meat-eating theropods.

The fossils will now be cleaned to see precisely which species they represent.

Mission Jurassic is a major undertaking involving researchers from the US, the UK and the Netherlands.

It is led by The Children's Museum of Indianapolis (TCMI) which has taken out a 20-year lease on a square mile (260 hectares) of ranch land.

FULL REPORT

[CaaC (John)+]

Anak Krakatau: Volcano's tsunami trigger was 'relatively small'

The scale of the tsunami hazard from volcanoes that collapse into the sea has been underestimated.

That's the conclusion of a new analysis of satellite pictures of Indonesia's Anak Krakatau showing the aftermath of its flank failure last December.

The study concludes that the volume of material that slipped into the water was actually relatively small.

And yet it generated destructive waves around the Sunda Strait as big as those expected from a much larger event.

More than 400 people died in the disaster on 22 December 2018; a further 7,000 were injured and nearly 47,000 were displaced from their homes.

• Indonesia tsunami: 'I clung to a bench'
• Collapsed volcano's tsunami simulated
• Finnish radar satellite eyes Anak Krakatau

FULL REPORT

[CaaC (John)+]

An Entire Scientific Observatory at The Bottom of The Ocean Mysteriously Vanished

"The devices were gone, the divers could not find them anymore," said marine biogeochemist Hermann Bange of the GEOMAR Helmholtz Centre for Ocean Research in Kiel.

"When the divers reached the bottom of the sea last week at the observatory's location, they found only the torn-off land cable. It was completely shredded."

Because of the size and mass of the thing, it's unlikely, German officials say, that it was removed by storms, currents, or marine animals.

The station, installed by the government-funded Kiel Ocean Research Centre and the Helmholtz Centre Geesthacht, consisted of two parts in a rack. There was the power supply, connected to land by the cable, and the observatory itself, containing sensors to monitor temperature, salinity, oxygen, currents and methane concentrations.

The observatory was positioned about 1.8 km (1.2 miles) offshore, north of Kiel in northern Germany. The place was a carefully selected restricted zone, and off-limits to boats – but it's possible nonetheless that someone was able to enter the area without detection and retrieve the €300,000 (about AUD$442,000) observatory from its seafloor depth of 22 metres (72 feet).

As for why it's possible that it was stolen for metal. Apparently seafloor salvage - especially from sunken pre-nuclear military vessels - is tremendously lucrative, and thieves have become adept at plundering entire ships without anyone noticing. Although the observatory was only installed in 2016, thieves may have seen an opportunity and pounced.

But it's not just the metal that has gone missing. The GEOMAR scientists are mourning the loss of their precious data. It's possible that another observatory could be built, but in the meantime, there is nothing monitoring that section of the sea for the first time since 1957.

This not only means there's going to be a gap in the data, but if something important happens in the undersea environment, we now have no surefire means of detecting or observing it.

"The data that we collect is downright priceless," Bange said. "They help research to register changes in the Baltic Sea and possibly take countermeasures."

The police are investigating the theft, but the team also hopes that publicising the loss will produce some leads.

"We would be very happy about the hints," Bange said. "Maybe someone saw something on the morning of 21 August at the Sperrgebiet 'Hausgarten' near the Hökholz campsite. Or someone finds parts of the frames somewhere on the beach."

They are also planning to try and get the station operational again as fast as possible.

https://www.msn.com/en-gb/news/offbeat/an-entire-scientific-observatory-at-the-bottom-of-the-ocean-mysteriously-vanished/ar-AAH1r6G