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Ice shelves propping up two major Antarctic glaciers are breaking up – CTV News

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Satellite images show that two important glaciers in the Antarctic are sustaining rapid damage at their most vulnerable points, leading to the breaking up of vital ice shelves with major consequences for global sea level rise.

The Pine Island and Thwaites glaciers, which sit side by side in West Antarctica on the Amundsen Sea, are among the fastest changing glaciers in the region, already accounting for 5% of global sea level rise. Scientists say the glaciers are highly sensitive to climate change.

A new study, published in the Proceedings of the National Academy of Sciences on Monday, found that the glaciers are weakening at their foundations and this damage over the past few decades is speeding up their retreat and the possible future collapse of their ice shelves.

The researchers, led by Stef Lhermitte, satellite expert at Delft University of Technology in the Netherlands, used satellite data to document the growth of the damaged areas from 1997 to 2019. The images showed highly crevassed areas and open fractures in the glaciers.

While rapid ice loss and melt of these Antarctic glaciers have been well documented, the new study suggests there could be future disintegration of the ice shelves to come.

“We knew they were sleeping giants and these were the ones losing a lot of miles (of ice), but how far and how much still remains a large uncertainty,” Lhermitte said. “These ice shelves are in the early phase of disintegration, they’re starting to tear apart.”

Thwaites Glacier is one of the largest and most unstable ice streams in Antarctica. It’s a giant mass of more than 192,000 square kilometers (74,000 square miles) — an area similar in size to the US state of Florida, or Great Britain.

The two glaciers effectively act as arteries connecting the West Antarctic ice sheet to the ocean. At their base are permanent floating ice shelves that act as a buttress to the fast-flowing ice behind it. The region holds enough ice to raise global sea levels by 1.2 meters (4 feet) according to NASA.

So what’s happening to the glaciers now?

Human-induced warming of our oceans and atmosphere because of the increasing release of heat-trapping greenhouse gases is weakening the planet’s ice shelves.

This ocean warming has increased the melting and calving (the breaking off of ice chunks) of Pine Island and Thwaites glaciers, studies show, while declining of snowfall means the glaciers can’t replenish themselves.

The damage researchers found pointed to a weakening of the glaciers’ shear margins — areas at the edges of the floating ice shelf where the fast moving ice meets the slower moving ice or rock underneath.

“Typically the ice shelf acts like slow traffic. It’s floating on the ocean but it buttresses the ice traffic behind it,” Lhermitte said. “So if you weaken this slow car, then the ice discharges more rapidly.”

That’s exactly what the researchers observed — and they believe these severely weakening parts of the glacier will accelerate mass ice loss. The study makes the case that this process should be included in models that project sea level rise, which it’s not currently a part of.

Researchers found that while the tearing of Pine Island Glacier’s shear margins has been documented since 1999, their satellite imagery shows that damage sped up dramatically in 2016.

Similarly, the damage to Thwaites Glacier began moving further upstream in 2016 and fractures rapidly started opening up near the glacier’s grounding line, which is where the ice meets the rock bed.

Researchers warn the process is creating a feedback loop — where the weakening ice shelf is speeding up the damage to the glacier’s vulnerable shear margins, which in turn leads to more damage and disintegration of the ice shelf.

Isabella Velicogna, Professor of Earth System Sciences at the University of California Irvine, who wasn’t involved in the study, said that, “with a process of weakening of the ice shelf included in models, it is likely that the glacier speed up will occur sooner and will be larger in magnitude, which means that sea level will rise faster than currently projected.”

Velicogna said that there are other processes that play “a much larger role” in glacier evolution, such as “the rate of retreat of the grounding line forced by a warmer ocean.”

Glaciers in trouble

The study comes on the heels of research published last week that found deep channels under the Thwaites Glacier may be allowing warm ocean water to melt the underside of its ice.

The cavities hidden beneath the ice shelf are likely to be the route through which warm ocean water passes underneath the ice shelf up to the grounding line, they said.

Over the past three decades, the rate of ice loss from Thwaites and its neighboring glaciers has increased more than five-fold. If Thwaites were to collapse, it could lead to an increase in sea levels of around 25 inches (64 centimeters).

And there’s more bad news for glaciers on the other side of the world. On Monday, scientists announced that a 44-square-mile chunk of ice, about twice the size of Manhattan, has broken off the Arctic’s largest remaining ice shelf in northeast Greenland in the past two years, raising fears of its rapid disintegration.

The territory’s ice sheet is the second biggest in the world behind Antarctica’s, and its annual melt contributes more than a millimeter rise to sea levels every year.

These recent findings from Antarctica show that the glaciers are “weakening from all angles,” Lhermitte said.

“Most of the weakening in this part of Antarctica is coming from below,” he said. “Warm ocean water gets to the (glaciers’) base and weakens them. What we observed is that this becomes so weakened, that they speed up and once they speed up, the shear margins speed up and start to break.”

Velicogna said the research “points to another Achilles’ heel of the system conducive to faster retreat, and triggered by climate change.”

“It seems that the more we look at these systems evolve, the more we see reasons for them to disappear more rapidly than we thought,” she said. “We have to act quickly on controlling climate change to preserve our future. The time to act is now.”

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Science Saturday 0919 – CGTN

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In this week’s Science Saturday, we look at science news ranging from possible signs of life on Venus to wildlife protection.

Scientists detect gas in Venus clouds linked to life on Earth

First, evidence of potential for life on the planet next door! A smelly, flammable gas called “phosphine” has been found on Venus. Here on Earth, phosphine is produced predominantly by anaerobic biological sources. So with this discovery, there’s a chance that there are some living organisms in the clouds of Venus. But scientists say further observations and modeling are needed to explore the origin of the gas in the planet’s atmosphere. The findings are published in the peer-reviewed journal – Nature Astronomy.

Washington bans TikTok downloads from U.S. app stores

Washington has announced a decision to ban TikTok downloads from app stores in the United States. Donald Trump, the U.S. president, is questioning plans by Chinese tech firm, ByteDance, to keep a majority stake in TikTok’s U.S. operations as part of a partnership deal with Oracle. Trump says any agreement to continue operating in U.S. must be “100% as far as national security is concerned.” He has called the popular video-sharing app a security threat, and says he will ban it unless it’s sold by ByteDance.

WWF report: Wildlife populations down by an average of 68 percent over past four decades

The world’s wildlife population is under threat! A new report by the World Wildlife Fund says human activity has wiped out two-thirds of the world’s wildlife since 1970. Latin America and the Caribbean are the world’s worst-affected areas, which have seen an average drop of 94 percent. The report says humans’ over-exploitation of wildlife, grassland conversion and climate change are among the major drivers of this devastating decline. Researchers are calling for changes in production and consumption patterns of food and energy, increased conservation efforts and a global collective effort.

Winners of Breakthrough Prizes announced for 2021

The winners of the 2021 Oscars of Science, also known as Breakthrough Prizes, have been revealed. Eight scientists have been recognized for their achievements in Mathematics, Fundamental Physics and Life Sciences. One of the recipients is David Baker, whose team designed a molecule that potentially inhabits the coronavirus that causes COVID-19. The team also successfully synthesized the proteins, which demonstrated a neutralizing antibody, shedding light on a potential new treatment to the disease. The prizes total 21 million U.S. dollars. Due to the global coronavirus pandemic, this year’s ceremony has been postponed until March 2021.

“Science Saturday” is part of CGTN’s science and technology series “Tech It Out.” The segment brings you the latest news about innovations and technological breakthroughs in the past two weeks from across the world.

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Physicists may have the first experimental evidence for a new type of Dark Boson

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Two experiments looking for the whisper of a particle that prevents the entire galaxy from flying away have recently published some contradictory results. One came out empty-handed, and the other gives you all the reasons to keep searching.

dark Bosons are Dark matter It is actually a candidate based on particles that transmit forces that do not exert much force.

Unlike bosons that we know better, like photons that bind molecules and gluons that bind atomic nuclei together, the exchange of dark bosons has little effect on the surrounding environment.

On the other hand, if they exist, their collective energy may be responsible for making up dark matter. The lost mass that provides the extra gravity needed to keep our stellar universe in a familiar form.

Unfortunately, the presence of such bosons will be as detectable as the murmurs in a storm. But for a physicist, given the right kind of experimentation, the noise can still be enough to stand out.

Two studies led by researchers from the Massachusetts Institute of Technology (MIT), and two studies led by Aarhus University in Denmark, examined the subtle differences in the position of electrons in isotopes that jump between energy levels. If it shook, this could be an obvious sign of the dark Boson’s nudge.

Theoretically, the boson comes from the interaction between the orbiting electron and the quarks that make up the neutron in the nucleus.

The team led by MIT used a small number of isotopes of ytterbium for the experiment, and calcium was a factor of choice by a group led by the University of Aarhus.

Both experiments sorted the data on specific plot types that measure this kind of motion in isotopes. Although the calcium-based experiment appeared as expected, the ytterbium plot was off and there was a statistically significant deviation in the linearity of the plot.

This is not the cause of any kind of celebration. First of all, boson can explain the number, but there may be a difference in the way you perform the calculations, this type of correction is called quadratic field shift.

You also need to explain exactly why you found something strange in one experiment and nothing in the other.

As always, we need more data. Much more. But figuring out exactly what makes up more than a quarter of the universe is one of the biggest questions in science, so every potential lead will be pursued with excitement.

Particles that transmit a new kind of force Standard model It’s not exactly ruled out in physics, but finding one is tremendous.

Last year, physicists were excited about particles moving at odd angles, alluding to a hitherto unknown force.

Similarly, the number of rebounding electrons in the XENON1T dark matter setup shook its tongue earlier this year, sparking speculation about a hypothetical dark matter candidate. Called axion.

While this result is interesting, we’ve broken our hearts before. In 2016, the dark matter candidate type was Madala Boson Was Rumors of discovery Among the data collected by the Large Hadron Collider to find Higgs particles.

This particle can be thought of as a kind of dark version of Higgs Boson, and dark matter lends its power without being clearly revealed in other ways.

CERN throws cold water Sad to say about that little gossip. This does not mean that such particles do not exist or that the signal is not tempting. It’s just that we really can’t confirm with some degree of confidence.

Larger colliderA clever new way of searching for subtle nudges and whispers of particles, more sensitive equipment, and almost non-existent, may one day get the answers we need.

Dark matter certainly won’t make it easier.

This study is Physical review letter, here and here.

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A new study finds that an iceberg may not have sunk the Titanic

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From famous mechanics

Just knowing when we think we know everything here TitanicUnsinkable ships, giant icebergs, “I am the king of the world,” etc. – come with interesting new discoveries that raise big questions about what really happened on the terrible night of April 14, 1912. The weather effect from space is really the reason Titanic Drowning?

🚢 You like ugly planes. so do we. Let’s get them together.

The main finding of the new study is that the northern hemisphere was subjected to a “moderate to severe” magnetic storm that night, which could have caused a change. TitanicNavigational readings affect its planned course And The crew shared their location during SOS signals.

The idea is very simple. The sun, which is powered by an atomic dynamo that burns millions of degrees, is bathed in sunlight. These, in turn, are punctuated by the size of the Earth by gigantic or larger explosives: solar flares.

“In a few minutes, they heat the material to millions of degrees and generate one billion megatons of TNT.” NASA explains that once the release is released. ”These flares are often caused by magnetic changes or collapses, and their explosions cause magnetic waves through the solar system.

It instinctively suggests that the hottest thing in the solar system experiences a lot of responses to rotating and changing magnetic fields. Earth is a successful habitat for living organisms, in part because humans have a protective magnetic field that represents an enormous amount of solar radiation and cosmic air that would throw us to the surface of a lifeless Mars-like planet. .

This magnetic field changes and changes over time, especially as the magnetic poles revolve around the Earth’s surface. Animals and humans have learned to rely on magnetic poles, in the form of man-made devices such as compasses. Animal knowledge for migration and navigation. Compasses, like hours, should be set to the correct units, for example Calculate magnetic answers It turns out in a natural way.

From here we reconnect Titanic. The newspaper is owned by author Mila Zinkova, which has published about four previous papers Titanic In the magazine RMetS Weather, Investigated the theory that mirrors or other visual disturbances played a role in the sinking. Now, Zinkova is using weather and space data to explore a different theory.

If a solar flare is so intense that it was marked by what is called Aurora borealis on that historic night, it could encircle the Earth’s magnetic field and wreak havoc with magnetic devices like the compass. Even today, solar flares disrupt the power grid and space traffic, and truly valuable backups. Safety can be maintained in a Faraday cage.

Image credit: Paramount – Twentieth Century Focus

 

Genkova writes that the impact on the compass affected the coordinates contained in the signs of the crisis. “The Titanic A fourth officer, Joseph Backshall, worked in the ship’s SOS condition. The Paxhall site was about 13 nautical kilometers (24 kilometers) from its original location, Zenkova wrote.

But the rescue plane Carpathia Perhaps this was wrong information. The Carpathian Compasses could be under the influence of a geomagnetic storm for 5.5 hours before and after. TitanicIt has SOS, and even hitting lifeboats, “Zinkova continues.” Therefore, a potential compound compass error may be one of the contributing factors to the successful rescue of survivors of the Titanic. “

It also indicates how the solar flare is localized. Ships caught in a certain area. Receive radio calls or miss them altogether. Returning to the ground or outside the affected area, everything seemed normal except upon contact or attempt Titanic And other ships nearby.

Source:- Aviation Analysis Wing

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