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Collapsing permafrost is transforming the Arctic’s waterways

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Some lakes in the Arctic are expanding while others are disappearing altogether due to climate change, which threatens to have devastating effects on the peoples of the Arctic who have used these freshwater systems for generations

Lakes, ponds and streams cover a large fraction of the low-lying tundra that circles the Arctic. For example, roughly 65,000 lakes and ponds lie within the Mackenzie Delta and an area to its east.

Lakes across this terrain often exist because of the impermeable nature of the permafrost around and below these lakes. Some of this permafrost has existed here since the last ice age.

Yet as the climate warms, this permafrost is at risk of thawing for the first time in tens of thousands of years. Permafrost thaw has already caused some of these lakes to drain and dry up, and others to expand. Dramatic changes over the last 70 years have been well documented through air photos and satellite images.

These lakes are linked by a vast network of rivers and streams, and are important habitat for large populations of migratory birds, fish and mammals. They are also vital to the lives of northerners, who use them for hunting, fishing, trapping, transportation, fresh water and recreation.

With increasing evidence of ecosystem destruction around the world related to the changing climate, there is also increasing concern that unique Arctic freshwater ecosystems are under threat.

Disappearing lakes

Lakes controlled by the presence of permafrost can drain rapidly if the permafrost gives way, a process called catastrophic lake drainage. Sometimes an entire lake can drain in as little as a day, like the one that we studied after it vanished from the landscape north of Inuvik, N.W.T., in 16 hours in August 1989.

The disappearance of this lake occurred as water seeped through cracks that had formed in ice wedges during the previous winter. The relatively warm lake water melted the ice within the permafrost, creating a new outlet channel.

Lake drainage presents a serious safety risk to hunters or fishers who may be downstream. It also destroys freshwater habitat, quickly converting it to land, and expands, or even forms, new stream channels.

Like many impacts of climate change on the Arctic, however, unexpected changes also occur. After our initial studies of draining lakes, we expected to find the number of lakes draining annually across this region would increase as the climate warmed.

An exceptionally warm summer in 2004 triggered this 300-metre-long slump associated with thawing permafrost In Noatak National Preserve, Alaska. Photo: National Parks Service / Flickr

Instead, we found lake drainage in this area had decreased by one-third between 1950 and 2000. This decrease is likely due to fewer extremely cold winter days that are needed for ice wedge cracking to occur over the winter.

Yet as warming continues, the upper layer of the soil that thaws each year is expected to get deeper and will likely lead to more lake drainage events. An increase in lake drainage has already been reported in Siberia, and this is likely the long-term future of many Arctic lowland lakes.

Expanding lakes

Other lowland lakes are expanding as ice in the lake shoreline melts. New lakes may also appear in the tundra depressions that form as ice-rich permafrost thaws, creating new aquatic habitat. Changes like this have been seen in Siberia, but they haven’t been observed in the Inuvik region yet.

This thawing of ice-rich permafrost, called thermokarst, results in changes in water chemistry and increases in water clarity. These changes will likely affect aquatic food webs in ways that are still poorly understood.

Three core sections from the upper metre of permafrost at a site north of Inuvik, N.W.T. White material is ice embedded in the permafrost. Photo: Niels Weiss

The Arctic is warming at two to three times the rate of the global average. But determining where the permafrost will thaw — in what way and how quickly — is a complicated puzzle affected by many factors.

For example, there are an increasing number of shrubs growing on the tundra. This affects the accumulation of blowing snow, and may speed up or slow down the rate of snow melt and shorten or lengthen the number of snow-free days. All of this affects permafrost thaw and freshwater systems.

Millennia of change ahead

Scientific organizations, governments and international groups around the world have all recently warned of the alarming impacts climate change is having — and will have — on the Arctic. Thawing permafrost is already destabilizing buildings, roads and airstrips, eroding coastlines and releasing more carbon into the atmosphere.

It is critically important to realize that permafrost thaw will not stop once the global climate has stabilized, whether at the Paris Agreement limits of 1.5C or 2C, or at much higher levels. Even if anthropogenic carbon emissions are reduced over the coming decades, the concentration of carbon dioxide in the atmosphere will remain above pre-industrial levels for centuries — and likely millennia. Temperatures will also remain high.

As long as the global average temperature stays above the pre-industrial average, permafrost will continue to thaw, ground ice will melt, the land will subside, lakes and streams and freshwater ecosystems will change dramatically, with devastating effects on the peoples of the Arctic who have used these freshwater systems for generations.

Over the next year, governments will make decisions that will limit the increase in global temperature to below 1.5C or allow global warming to further increase to 2C or more. Our decisions will impact the Arctic and the globe for generations.

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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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