Connect with us

Science

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

Published

 on



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.

“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

Science

New species of crested dinosaur identified in Mexico

Published

 on

A team of palaeontologists in Mexico have identified a new species of dinosaur after finding its 72 million-year-old fossilized remains almost a decade ago, Mexico’s National Institute of Anthropology and History (INAH) said on Thursday.

The new species, named Tlatolophus galorum, was identified as a crested dinosaur after 80% of its skull was recovered, allowing experts to compare it to other dinosaurs of that type, INAH said.

The investigation, which also included specialists from the National Autonomous University of Mexico, began in 2013 with the discovery of an articulated tail in the north-central Mexican state of Coahuila, where other discoveries have been made.

“Once we recovered the tail, we continued digging below where it was located. The surprise was that we began to find bones such as the femur, the scapula and other elements,” said Alejandro Ramírez, a scientist involved in the discovery.

Later, the scientists were able to collect, clean and analyze other bone fragments from the front part of the dinosaur’s body.

The palaeontologists had in their possession the crest of the dinosaur, which was 1.32 meters long, as well as other parts of the skull: lower and upper jaws, palate and even a part known as the neurocranium, where the brain was housed, INAH said.

The Mexican anthropology body also explained the meaning of the name – Tlatolophus galorum – for the new species of dinosaur.

Tlatolophus is a mixture of two words, putting together a term from the indigenous Mexican language of Nahuatl that means “word” with the Greek term meaning “crest”. Galorum refers to the people linked to the research, INAH said.

 

(Reporting by Abraham Gonzalez; Writing by Drazen Jorgic; Editing by Ana Nicolaci da Costa)

Continue Reading

Science

Alberta family searches for answers in teen's sudden death after COVID exposure, negative tests – CBC.ca

Published

 on


A southern Alberta mother and father are grappling with the sudden, unexplained death of their 17-year-old daughter, and with few answers, they’re left wondering if she could be the province’s youngest victim of COVID-19.

Sarah Strate — a healthy, active Grade 12 student at Magrath High School who loved singing, dancing and being outdoors — died on Monday, less than a week after being notified she’d been exposed to COVID-19.

While two tests came back negative, her parents say other signs point to the coronavirus, and they’re waiting for more answers. 

“It was so fast. It’s all still such a shock,” said Sarah’s mother, Kristine Strate. “She never even coughed. She had a sore throat and her ears were sore for a while, and [she had] swollen neck glands.”

Kristine said Sarah developed mild symptoms shortly after her older sister — who later tested positive for COVID-19 —  visited from Lethbridge, one of Alberta’s current hot spots for the virus.

The family went into isolation at their home in Magrath on Tuesday, April 20. They were swabbed the next day and the results were negative.

‘Everything went south, super-fast’

By Friday night, Sarah had developed fever and chills. On Saturday, she started vomiting and Kristine, a public health nurse, tried to keep her hydrated.

“She woke up feeling a bit more off on Monday morning,” Kristine said. “And everything went south, super-fast.”

Sarah had grown very weak and her parents decided to call 911 when she appeared to become delirious.

“She had her blanket on and I was talking to her and, in an instant, she was unresponsive,” said Kristine, who immediately started performing CPR on her daughter.

When paramedics arrived 20 minutes later, they were able to restore a heartbeat and rushed Sarah to hospital in Lethbridge, where she died.

“I thought there was hope once we got her heart rate back. I really did,” recalled Sarah’s father, Ron.

“He was praying for a miracle, and sometimes miracles don’t come,” said Kristine.

Strate’s parents say her health deteriorated quickly after being exposed to COVID-19. She died at Chinook Regional Hospital in Lethbridge on Monday. (Ron Strate)

Searching for answers

At the hospital, the family was told Sarah’s lungs were severely infected and that she may have ended up with blood clots in both her heart and lungs, a condition that can be a complication of COVID-19.

But a second test at the hospital came back negative for COVID-19.

“There really is no other answer,” Ron said. “When a healthy 17-year-old girl, who was sitting up in her bed and was able to talk, and within 10 minutes is unconscious on our floor — there was no reason [for it].”

The province currently has no record of any Albertans under the age of 20 who have died of COVID-19.

According to the Strate family, the medical examiner is running additional blood and tissue tests, in an effort to uncover the cause of Sarah’s death.

‘Unusual but not impossible’

University of Alberta infectious disease specialist Dr. Lynora Saxinger, who was not involved in Sarah’s treatment, says it is conceivable that further testing could uncover evidence of a COVID-19 infection, despite two negative test results.

However, she hasn’t seen a similar case in Alberta.

“It would be unusual but not impossible because no test is perfect. We have had cases where an initial test is negative and then if you keep on thinking it’s COVID and you re-test, you then can find COVID,” she said.

According to Saxinger, the rate of false negatives is believed to be very low. But it can happen if there are problems with the testing or specimen collection.

She says people are more likely to test positive after symptoms develop. 

“The best sensitivity of the test is around day four or five of having symptoms,” she said. “So you can miss things if you test very, very early. And with new development of symptoms, it’s always a good time to re-test because then the likelihood of getting a positive test is a little higher. But again, no test is perfect.” 

Sarah deteriorated so quickly — dying five days after she first developed symptoms — she didn’t live long enough to make it to her follow-up COVID-19 test. Instead, it was done at the hospital.

‘An amazing kid’

The Strate family now faces an agonizing wait for answers — one that will likely take months — about what caused Sarah’s death.

But Ron, who teaches at the school where Sarah attended Grade 12, wants his daughter to be remembered for the life she lived, not her death.

Strate, pictured here at three years old, had plans to become a massage therapist. She attended Grade 12 at Magrath High School and was an active, healthy teenager who was involved in sports, music and the school’s suicide prevention group. (Ron Strate)

Sarah was one of five children. Ron says she was strong, active and vibrant and had plans to become a massage therapist after graduating from high school.

She played several sports and loved to sing and dance as part of a show choir. She was a leader in the school’s suicide prevention group and would stand up for other students who were facing bullying.

“She’s one of the leaders in our Hope Squad … which goes out and helps kids to not be scared,” he father said.

“She’s an amazing kid.”

Sarah would often spend hours helping struggling classmates, and her parents hope her kindness is not forgotten.

“She’d done so many good things. Honestly, I’ve got so many messages from parents saying, ‘You have no idea how much your daughter helped our kid,'” said Ron.

“This 17-year-old girl probably lived more of a life in 17 years than most adults will live in their whole lives. She was so special. I love her so much.”

Let’s block ads! (Why?)



Source link

Continue Reading

Science

China launches key module of space station planned for 2022

Published

 on

BEIJING (Reuters) -China launched an unmanned module on Thursday containing what will become living quarters for three crew on a permanent space station that it plans to complete by the end of 2022, state media reported.

The module, named “Tianhe”, or “Harmony of the Heavens”, was launched on the Long March 5B, China’s largest carrier rocket, at 11:23 a.m. (0323 GMT) from the Wenchang Space Launch Centre on the southern island of Hainan.

Tianhe is one of three main components of what would be China’s first self-developed space station, rivalling the only other station in service – the International Space Station (ISS).

The ISS is backed by the United States, Russia, Europe, Japan and Canada. China was barred from participating by the United States.

“(Tianhe) is an important pilot project in the building of a powerful nation in both technology and in space,” state media quoted President Xi Jinping as saying in a congratulatory speech.

Tianhe forms the main living quarters for three crew members in the Chinese space station, which will have a life span of at least 10 years.

The Tianhe launch was the first of 11 missions needed to complete the space station, which will orbit Earth at an altitude of 340 to 450 km (211-280 miles).

In the later missions, China will launch the two other core modules, four manned spacecraft and four cargo spacecraft.

Work on the space station programme began a decade ago with the launch of a space lab Tiangong-1 in 2011, and later, Tiangong-2 in 2016.

Both helped China test the programme’s space rendezvous and docking capabilities.

China aims to become a major space power by 2030. It has ramped up its space programme with visits to the moon, the launch of an uncrewed probe to Mars and the construction of its own space station.

In contrast, the fate of the ageing ISS – in orbit for more than two decades – remains uncertain.

The project is set to expire in 2024, barring funding from its partners. Russia said this month that it would quit the project from 2025.

Russia is deepening ties with China in space as tensions with Washington rise.

Moscow has slammed the U.S.-led Artemis moon exploration programme and instead chosen to join Beijing in setting up a lunar research outpost in the coming years.

(Reporting by Ryan Woo and Liangping Gao; Editing by Christian Schmollinger, Simon Cameron-Moore and Lincoln Feast.)

Continue Reading

Trending