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Giant mantle plume suggests Mars is more active than previously believed

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Although most volcanic and tectonic activity on Mars occurred during the first 1.5 billion years of its geologic history, recent volcanism, tectonism, and active seismicity in Elysium Planitia reveal ongoing activity. However, this recent pulse in volcanism and tectonics is unexpected on a cooling Mars.

A new study by scientists from the University of Arizona presents multiple lines of evidence that reveal the presence of a giant active mantle plume on present-day Mars. The study challenges current views of Martian geodynamic evolution with a report on discovering an active mantle plume pushing the surface upward and causing earthquakes and volcanic eruptions.

Jeff Andrews-Hanna, an associate professor of planetary science at the LPL, said, “We have strong evidence for mantle plumes being active on Earth and Venus, but this isn’t expected on a small and supposedly cold world like Mars. Mars was most active 3 to 4 billion years ago, and the prevailing view is that the planet is essentially dead today.”

Adrien Broquet, a postdoctoral research associate at the UArizona Lunar and Planetary Laboratory, said, “A tremendous amount of volcanic activity early in the planet’s history built the tallest volcanoes in the solar system and blanketed most of the northern hemisphere in volcanic deposits. What little activity has occurred in recent history is typically attributed to passive processes on a cooling planet.”

The Elysium Planitia plain, located in the northern lowlands of Mars near the equator, caught the attention of scientists due to a startling level of activity. Elysium Planitia has undergone significant eruptions over the past 200 million years, in contrast to other volcanic zones on Mars that haven’t experienced significant activity in billions of years.

Andrews-Hanna said, “Previous work by our group found evidence in Elysium Planitia for the youngest volcanic eruption known on Mars. It created a small explosion of volcanic ash around 53,000 years ago, which in geologic time is essentially yesterday.”

The Cerberus Fossae, a series of young fissures that span more than 800 miles over the Martian surface, is the source of the volcanism in Elysium Planitia. Recently, the InSight team at NASA discovered that almost all marsquakes originate from this area. Although the young age of this volcanic and tectonic activity had been established, its root cause was still unknown.

Broquet said, “We know that Mars does not have plate tectonics, so we investigated whether the activity we see in the Cerberus Fossae region could be the result of a mantle plume.”

Artist’s impression of an active mantle plume – a large blob of warm and buoyant rock – rising from deep inside Mars and pushing up Elysium Planitia, a plain within the planet’s northern lowlands.Adrien Broquet & Audrey Lasbordes

The scientists discovered evidence of a similar series of events on Mars when they examined the features of Elysium Planitia. One of the highest places in Mars’ vast northern lowlands, the surface has been raised by more than a mile. The existence of a mantle plume is compatible with the uplift being supported from deep within the globe, according to analyses of minor fluctuations in the gravitational field.

Additional measurements supported the theory that something pushed the surface up after the craters formed by revealing that the floor of impact craters is inclined in the direction of the plume. Finally, when scientists used a tectonic model to the region, they discovered that the only explanation for the extension that created the Cerberus Fossae was the existence of a massive plume 2,500 miles wide.

Broquet said, “In terms of what you expect to see with an active mantle plume, Elysium Planitia is checking all the right boxes. The finding poses a challenge for models used by planetary scientists to study the thermal evolution of planets. This mantle plume has affected an area of Mars roughly equivalent to that of the continental United States. Future studies will have to find a way to account for a huge mantle plume that wasn’t expected to be there.”

“We used to think InSight landed in one of the most geologically boring regions on Mars – a nice flat surface that should roughly represent the planet’s lowlands. Instead, our study demonstrates that InSight landed right on top of an active plume head.”

“Having an active mantle plume on Mars today is a paradigm shift for our understanding of the planet’s geologic evolution, similar to when analyses of seismic measurements recorded during the Apollo era demonstrated the moon’s core to be molten.”

Scientists noted, “Their findings could also have implications for life on Mars. The studied region experienced floods of liquid water in its recent geologic past, though the cause has remained a mystery. The same heat from the plume fueling ongoing volcanic and seismic activity could also melt ice to make the floods – and drive chemical reactions that could sustain life deep underground.”

Andrews-Hanna said“Microbes on Earth flourish in environments like this, and that could be true on Mars, as well. The discovery goes beyond explaining the enigmatic seismic activity and resurgence in volcanic activity. Knowing that there is an active giant mantle plume underneath the Martian surface raises important questions regarding how the planet has evolved. We’re convinced that the future has more surprises in store.”

Journal Reference:

  1. Broquet, A., Andrews-Hanna, J.C. Geophysical evidence for an active mantle plume underneath Elysium Planitia on Mars. Nat Astron (2022). DOI: 10.1038/s41550-022-01836-3

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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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