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Thwaites Glacier Retreat Highlighting Concerns for Its Future – AZoCleantech

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For researchers attempting to anticipate the global sea level rise rate, the Thwaites Glacier in West Antarctica, which is about the size of Florida, has been a significant sticking point.

The R/V Nathaniel B. Palmer was photographed from a drone at Thwaites Glacier ice front in February 2019. Image Credit: Alexandra Mazur/University of Gothenburg

When seen in geological periods, this vast ice stream is already in a stage of rapid retreat, known as a “collapse,” which has raised many questions about how much ice it will eventually lose to the ocean and how quickly.

The effects of Thwaites’ retreat might be terrifying: if the glacier and its surrounding glacial basins vanish entirely, the sea level could rise by three to ten feet.

The concern is increased by a recent study published in Nature Geoscience headed by marine geophysicist Alastair Graham of the College of Marine Science at the University of South Florida.

The seafloor in front of the glacier was crucially imaged in high resolution for the first time, providing researchers with a window into how quickly Thwaites advanced and receded in the past.

The breathtaking footage offers a kind of crystal ball to look into Thwaites’ future and reveals geologic aspects that are new to science. Understanding previous behavior is essential to predicting future behavior in humans and ice sheets.

The crew recorded more than 160 parallel ridges left behind when the glacier’s front edge retreated and oscillated with the daily tides.

It’s as if you are looking at a tide gauge on the seafloor. It blows my mind how beautiful the data are.

Alastair Graham, Marine Geophysicist, College of Marine Science, University of South Florida

Graham added that despite its beauty, Thwaites is troubling because the rate of retreat scientists have lately discovered is slow compared to the quickest rates of change in its past.

The scientists examined the rib-like structures 700 m (just under half a mile) beneath the Arctic Ocean to comprehend Thwaites’ previous retreat. They also considered the region’s tidal cycle, as anticipated by computer models, to demonstrate that one rib must have developed each day.

The front of the glacier lost contact with a ridge on the seafloor somewhere in the past 200 years, and for a period of fewer than six months, it retreated at a rate of more than 2.1 km per year (1.3 miles per year), which is twice the rate observed by satellites between 2011 and 2019.

Our results suggest that pulses of very rapid retreat have occurred at Thwaites Glacier in the last two centuries, and possibly as recently as the mid-20th Century,” Graham said.

Thwaites is holding on today by its fingernails, and we should expect to see big changes over small timescales in the future–even from one year to the next–once the glacier retreats beyond a shallow ridge in its bed,” said Robert Larter, a marine geophysicist and study co-author of the British Antarctic Survey.

The team, which includes researchers from the United States, the United Kingdom, and Sweden, deployed a cutting-edge orange robotic vehicle dubbed “Rán” from the R/V Nathaniel B. Palmer during an expedition in 2019 to gather the imagery and accompanying geophysical data.

According to Graham, Rán—run by researchers at the University of Gothenburg in Sweden—set off on a 20-hour journey that was both dangerous and fortunate. It did so in harsh conditions during an extraordinary summer remarkable for its absence of sea ice, mapping a region of the seabed in front of the glacier about the size of Houston.

This made it possible for scientists to reach the glacier front for the first time.

This was a pioneering study of the ocean floor, made possible by recent technological advancements in autonomous ocean mapping and a bold decision by the Wallenberg foundation to invest in this research infrastructure,” said Anna Wåhlin, a physical oceanographer from the University of Gothenburg who deployed Rán at Thwaites.

The images Ran collected to give us vital insights into the processes happening at the critical junction between the glacier and the ocean today,” Wåhlin said.

It was truly a once-in-a-lifetime mission.

Alastair Graham, Marine Geophysicist, College of Marine Science, University of South Florida

Graham stated that to more precisely date the ridge-like characteristics, the researchers would like to sample the seabed sediments directly.

But the ice closed in on us pretty quickly and we had to leave before we could do that on this expedition,” he said.

There are still many unanswered concerns, but one thing is certain, according to Graham: The Antarctic ice sheets are not at all what researchers had believed them to be.

Just a small kick to Thwaites could lead to a big response,” he said.

According to the United Nations, about 40% of people live within 60 miles of the coast.

This study is part of a cross-disciplinary collective effort to understand the Thwaites Glacier system better, and just because it’s out of sight, we cannot have Thwaites out of mind. This study is an important step forward in providing essential information to inform global planning efforts,” said Tom Frazer, dean of the USF College of Marine Science

The National Science Foundation and the UK Natural Environment Research Council funded the project through the International Thwaites Glacier Collaboration.

Journal Reference:

Graham, A. G. C., et al. (2022) Rapid retreat of Thwaites Glacier in the pre-satellite era. Nature Geoscience. doi.org/10.1038/s41561-022-01019-9.

Source: https://www.usf.edu/

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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