Connect with us


These lava lakes drained catastrophically—and scientists caught it in action – National Geographic



When Yves Moussallam trekked around Vanuatu’s Ambrym volcano in the winter of 2018, the ground was blanketed in green, and five incandescent lakes of molten rock burbled in the volcano’s caldera. Just two weeks later, though, he found himself in a landscape devoid of color. Gray ash coated each rock and crevice, and the lakes sat empty, their lava vanished like water swirled down a drain.

“It looked like everything was in black-and-white,” says Moussallam, a volcanologist at Columbia University who is also associated with France’s Laboratoire Magmas et Volcans. “The whole caldera area had completely changed.”

This transformation came in the wake of an extraordinary eruption that surprised scientists with its progression. While some of the lava spurted up from nearby cracks, the vast majority moved underground—a slug of magma big enough to fill 160,000 Olympic swimming pools. As the team reports in Scientific Reports, the process cracked the earth, sending coasts soaring into the air, and brought lava burbling up onto the ocean floor.

Genius Dog 336 x 280 - Animated

“It’s kind of a negative eruption, in a way,” says volcanologist Clive Oppenheimer of the University of Cambridge, who was not on the study team. “It’s not stuff coming out of the ground, it’s the magma migrating beneath the ground.”

View Images

Lava roils in one of Ambrym’s lakes before the 2018 eruption. Lava lakes can act like windows to the deep, giving clues to what’s happening deep beneath the surface.

Photograph by Yves Moussallam

The new study provides a rare and detailed portrait of Ambrym’s activity above and below, which can help geologists unravel the myriad processes that contribute to volcanic activity.

“As volcanologists, we’re always trying to understanding what’s going on kilometers beneath our feet, and that can be difficult because we don’t have direct access to the magmatic reservoirs,” says study coauthor Tara Shreve, a Ph.D. candidate at the Institut de Physique du Globe de Paris. But the new study combines an array of clues to better understand the events conspiring deep underground, providing important details about Ambrym’s volcanic capabilities—and the variety of hazards such eruptions can present.

“It’s not like a lab science, where you can go and do the same experiment over and over and over again,” says Emily Montgomery-Brown, a geodesist at U.S. Geological Survey’s California Volcano Observatory who was not part of the study team. “We learn so much from every single eruption.”

A chance sighting

Moussallam initially ventured to Ambrym as part of a study analyzing the prodigious gasses puffing from volcanoes across the Vanuatu arc, a project funded by the National Geographic Society. They monitored gasses at three of Ambrym’s lava lakes before heading on their way. Two weeks later, they were prepping for their flight back home from Vanuatu’s capital city, Port Vila, when they got the news: Ambrym was erupting.

The team caught a helicopter back to the island and gaped at the difference. The molten lakes had disappeared. A lava flow cooled in the distance. Nearby trees crackled with flames. Connecting the dots, they at first assumed that magma had burst to the surface, draining the system.

“We thought that was the story,” Moussallam says. But, as they later discovered, the eruption was still playing out deep under their feet.

Intense earthquakes began rocking the island, and hefty fractures cut through the ground, forming steps in the landscape. In the coastal village of Pamal, eight miles from the caldera’s rim, roads were cleaved in two and houses were thrust feet into the air. The ground split under one building, leaving part of the structure hanging in mid-air.

“Clearly something was still going on,” Moussallam says. “It was really surprising it was so far away from where the eruption had begun.”

Pairing satellite analyses with on-the-ground observations, the team later learned that this was all part of a multi-day saga, as 14 billion cubic feet of magma shifted eastward, squeezing through deep cracks under the island for more than 10 miles.

This sudden addition of subsurface material shoved the coasts upward some six and a half feet, exposing a vast expanse of coral and red algae to deadly sunlight, says Géoazur’s Bernard Pelletier, a study coauthor who surveyed the coasts post-eruption. The loss was also felt at the volcano’s gaping summit caldera, which sunk by roughly eight feet.

On December 18, four days after the eruption began, volcanic pumice washed up on the island’s eastern shore—likely the result of magma finally oozing out from the subsurface into coastal waters.

Peering inside Earth

This type of draining through deep fissures in the ground, known as rift zone volcanism, is not unheard of, but Ambrym is an unlikely candidate.

Rift zone volcanism is most common in places where tectonic plates are separating, and extension in the crust pulls the land apart. Take, for example, the deep fissures found in Iceland’s volcanoes, which frequently line up with the pair of tectonic plates separating beneath the island country. Rift volcanism is also responsible for much activity at Kilauea which, along with the underlying flanks of Mauna Loa, is slowly sliding into the sea, Montgomery-Brown explains.

Volcanoes 101

About 1,500 active volcanoes can be found around the world. Learn about the major types of volcanoes, the geological process behind eruptions, and where the most destructive volcanic eruption ever witnessed occurred.

By contrast, Vanuatu sits near the tectonic collision zone between the Pacific and Indo-Australian plates, which compresses the region. However, the latest analysis suggests that Vanuatu’s pressure-packed position isn’t a problem. The rift that drained the magma is oriented so that the two sides separate in the direction of least compression, allowing the fracture to inflate “like a whoopee cushion,” Montgomery-Brown says. The team’s modeling suggests that the pocket of magma inside the rift likely bulged more than 13 feet across in some spots.

One lingering curiosity is what happened to the volcano’s gas, says Philipson Bani, a volcanologist at France’s Institute of Research for Development who was not on the study team. Ambrym has been one of the greatest natural emitters of carbon dioxide and other volcanic gasses around the world for many years. How it maintained such activity remains a mystery, he says. Then the eruption happened and, almost overnight, the gaseous factory seemed to turn off.

“How can you just shut off the pipe?” Bani says. “On Ambrym, we have more and more and more gas in the past, and then boom. It stops.”

Magmatic budgets

Still more clues to Ambrym’s eruption may continue to emerge, Moussallam notes. He’s currently looking into the chemistry of the lavas, which seem to be of at least two different compositions, likely originating from separate reservoirs. While more research is required to confirm the find, it hints that the eruption’s ignition spark might have been the formation of a new connection between the pair of reservoirs.

Detailed analyses of volcanic systems, like this latest Ambrym paper, are important in understanding the mechanics of volcanic eruptions. Such work might even help give clues to a volcano’s magmatic budget, revealing how much molten rock might be available for future eruptions, Mongomery-Brown says.

Just months before Ambrym drained, Kilauea’s lava lakes in Hawaii were making their own fiery exit from deep cracks on the volcano’s flanks. But Montgomery-Brown and her colleagues recently found that Kilauea’s extensive eruption and the collapse of its summit crater came from the release of a mere 11 to 33 percent of its shallow magma reservoir. The find sparked many questions, including why the eruption stopped at all.

In these ways, both eruptions provide a vital look into the dynamic and varied ways volcanoes work, says Matthew Patrick, a geologist with the United States Geological Survey’s Hawaiian Volcano Observatory, who was not involved with the new study.

“Now, for both volcanoes we’re in this recovery phase,” he says, “and the big question is, What’s next?”

Let’s block ads! (Why?)

Source link

Continue Reading


Scientists revive 48500-year-old ‘zombie virus’ buried in ice



The thawing of ancient permafrost due to climate change may pose a new threat to humans, according to researchers who revived nearly two dozen viruses – including one frozen under a lake more than 48,500 years ago.

European researchers examined ancient samples collected from permafrost in the Siberia region of Russia. They revived and characterized 13 new pathogens, what they termed “zombie viruses,” and found that they remained infectious despite spending many millennia trapped in the frozen ground.

Scientists have long warned that the thawing of permafrost due to atmospheric warming will worsen climate change by freeing previously trapped greenhouse gases like methane. But its effect on dormant pathogens is less well understood.

Genius Dog 336 x 280 - Animated

The team of researchers from Russia, Germany and France said the biological risk of reanimating the viruses they studied was “totally negligible” due to the strains they targeted, mainly those capable of infecting amoeba microbes. The potential revival of a virus that could infect animals or humans is much more problematic, they said, warning that their work can be extrapolated to show the danger is real.

“It is thus likely that ancient permafrost will release these unknown viruses upon thawing,” they wrote in an article posted to the preprint repository bioRxiv that hasn’t yet been peer-reviewed.

We apologize, but this video has failed to load.

“How long these viruses could remain infectious once exposed to outdoor conditions, and how likely they will be to encounter and infect a suitable host in the interval, is yet impossible to estimate.”

“But the risk is bound to increase in the context of global warming when permafrost thawing will keep accelerating, and more people will be populating the Arctic in the wake of industrial ventures,” they said.

Source link

Continue Reading


McMaster University team to finalize plans with CSA on deployment of satellite




A team of students from McMaster University which has spent close to seven years creating a satellite to measure space radiation is set to finalize plans to deploy the device in outer space.

The Canadian Space Agency (CSA) is welcoming the developers this week to finalize preparation of their CubeSat, a miniaturized satellite to further the understanding of long-term exposure to space radiation.

Operation Team Lead with McMaster’s NEUtron DOSimetry & Exploration (NEUDOSE) mission Taren Ginter says the idea was selected for the Canadian Cube Sat project in 2018. In simple terms, Ginter says it measures the effects of ionizing radiation on the human body.

Genius Dog 336 x 280 - Animated

Some of the financial backing for the project came in the form of $200,000 awarded to the McMaster developers by the CSA.

Ginter says as spaceflight and deep-space missions become a reality in the future, astronauts will likely have to face radiation that is distinct from the radiation experienced on earth.

The question the NEUDOSE mission is looking to answer is what kind and how much radiation astronauts will face on a multi-year mission in space.

“So our goal is to get a sense of those radiation differences and hopefully we can implement better safety precautions so that astronauts are protected,” Ginter explained.

The McMaster radiation detector is the size of a loaf of bread and is expected to be placed in a small satellite prior to being deployed into space, free floating like an astronaut would.

If it works properly, the device will send real-time radiation measurements back to the team at the university.

The device is the concept of Dr. Andrei Hanu, who came up with the idea while working at NASA as a research scientist.

Hanu led the first team of developers in 2015, jokingly referring to the device as the “igloo” due to its top which is dome-shaped.

However, Ginter says the satellite will actually look like a bunch of solar panels connected together due to the fact it needs to be charged by sunlight.

“But inside of the satellite, we have our charged and neutral particle tissue equivalent proportional counter, which is quite a mouthful,” Ginter said.

“So this is the actual payload of our satellite that will be looking at the radiation in low-earth orbit and then sending that information back down to ground station at McMaster.”

The NEUDOSE CubeSat will head to the CSA this week for a final step confirming it meets standards to be deployed from the International Space Station (ISS).

The life expectancy of the device is approximately one year in the Earth’s orbit after it’s been deployed.

The McMaster creation is earmarked for the ISS in February following launch from a SpaceX Dragon ship in Florida.

Source link

Continue Reading


Explainable AI-based physical theory for advanced materials design: Scientists develop an ‘extended Landau free energy model’ for causal analysis and visualization in nano-magnetic devices with AI and topology



Microscopic materials analysis is essential to achieve desirable performance in next-generation nanoelectronic devices, such as low power consumption and high speeds. However, the magnetic materials involved in such devices often exhibit incredibly complex interactions between nanostructures and magnetic domains. This, in turn, makes functional design challenging.

Traditionally, researchers have performed a visual analysis of the microscopic image data. However, this often makes the interpretation of such data qualitative and highly subjective. What is lacking is a causal analysis of the mechanisms underlying the complex interactions in nanoscale magnetic materials.

In a recent breakthrough published in Scientific Reports, a team of researchers led by Prof. Masato Kotsugi from Tokyo University of Science, Japan succeeded in automating the interpretation of the microscopic image data. This was achieved using an “extended Landau free energy model” that the team developed using a combination of topology, data science, and free energy. The model could illustrate the physical mechanism as well as the critical location of the magnetic effect, and proposed an optimal structure for a nano device. The model used physics-based features to draw energy landscapes in the information space, which could be applied to understand the complex interactions at the nanoscales in a wide variety of materials.

“Conventional analysis are based on a visual inspection of microscope images, and the relationships with the material function are expressed only qualitatively, which is a major bottleneck for material design. Our extended Landau free energy model enables us to identify the physical origin and location of the complex phenomena within these materials. This approach overcomes the explainability problem faced by deep learning, which, in a way, amounts to reinventing new physical laws,” Prof. Kotsugi explains. This work was supported by KAKENHI, JSPS, and the MEXT-Program for Creation of Innovative Core Technology for Power Electronics Grant.

Genius Dog 336 x 280 - Animated

When designing the model, the team made use of the state-of-art technique in the fields of topology and data science to extend the Landau free energy model. This led to a model that enabled a causal analysis of the magnetization reversal in nanomagnets. The team then carried out an automated identification of the physical origin and visualization of the original magnetic domain images.

Their results indicated that the demagnetization energy near a defect gives rise to a magnetic effect, which is responsible for the “pinning phenomenon.” Further, the team could visualize the spatial concentration of energy barriers, a feat that had not been achieved until now. Finally, the team proposed a topologically inverse design of recording devices and nanostructures with low power consumption.

The model proposed in this study is expected to contribute to a wide range of applications in the development of spintronic devices, quantum information technology, and Web 3.

“Our proposed model opens up new possibilities for optimization of magnetic properties for material engineering. The extended method will finally allow us to clarify ‘why’ and ‘where’ the function of a material is expressed. The analysis of material functions, which used to rely on visual inspection, can now be quantified to make precise functional design possible,” concludes an optimistic Prof. Kotsugi.

Story Source:

Materials provided by Tokyo University of Science. Note: Content may be edited for style and length.

Source link

Continue Reading