Rutgers-led study sheds light on subsurface melting of thick ice billions of years ago — ScienceDaily

The most habitable region for life on Mars would have been up to several miles below its surface, likely due to subsurface melting of thick ice sheets fueled by geothermal heat, a Rutgers-led study concludes.

The study, published in the journal Science Advances, may help resolve what’s known as the faint young sun paradox — a lingering key question in Mars science.

“Even if greenhouse gases like carbon dioxide and water vapor are pumped into the early Martian atmosphere in computer simulations, climate models still struggle to support a long-term warm and wet Mars,” said lead author Lujendra Ojha, an assistant professor in the Department of Earth and Planetary Sciences in the School of Arts and Sciences at Rutgers University-New Brunswick. “I and my co-authors propose that the faint young sun paradox may be reconciled, at least partly, if Mars had high geothermal heat in its past.”

Our sun

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Most detailed ever study of Greenland ice sheet warns of irreversible ice loss — ScienceDaily

In a study published this week in The Cryosphere, researchers from the National Centre for Atmospheric Science and University of Reading demonstrate how climate change could lead to irreversible sea level rise as temperatures continue to rise and the Greenland ice sheet continues to decline.

The massive ice sheet faces a point of no return, beyond which it will no longer fully regrow, permanently changing sea levels around the world.

The Greenland ice sheet is seven times the area of the UK, and stores a large amount of the Earth’s frozen water. At current rates of melting, it contributes almost 1mm to sea level per year, and accounts for around a quarter of total sea level rise.

Since 2003, despite seasonal periods of growth, Greenland’s ice sheet has lost three and a half trillion tonnes of ice.

Rising sea levels are one of the most severe effects of climate

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Melting Ice in Norway Reveals Ancient Arrows | Smart News

A melting ice patch in Norway has revealed the remnants of dozens of arrows and other artifacts, some dating to the Stone Age, Chris Baraniuk reports for New Scientist.

Researchers from the Universities of Cambridge, Oslo and Bergen have discovered 68 arrow shafts, some with arrowheads attached. The arrowheads are made of a range of materials, including bone, slate, iron and mussel shell. In some cases, the ice even preserved twine and tar used to hold the arrow together. They published their findings earlier this week in the journal The Holocene.

William Taylor, an anthropologist at the University of Colorado Boulder who was not involved in the study, tells New Scientist that the discoveries represent a “treasure trove” not usually found in a single patch of melting ice.

“You might expect a handful of items if you were lucky,” he says. “It’s extremely rare and extremely important.”

The

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Changes in the Antarctic ice sheet were driven by the melting ice sheets in the Northern Hemisphere — ScienceDaily

Over the past 40,000 years, ice sheets thousands of kilometres apart have influenced one another through sea level changes, according to research published today in Nature. New modelling of ice sheet changes during the most recent glacial cycle by a McGill-led team offers a clearer idea of the mechanisms that drive change than had previously existed and explains newly available geological records. The study demonstrates, for the first time, that during this period, changes in the Antarctic ice sheet were driven by the melting ice sheets in the Northern Hemisphere.

As the climate cooled, during the last Ice Age, water became locked up in land ice in the Northern Hemisphere leading to dropping sea levels in Antarctica and consequent growth of the ice sheet. As the climate warmed, on the other hand, as it did through the period of deglaciation, the retreating ice in the Northern Hemisphere led to

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Climate change may increase drownings as ice thins, study finds

Falling through ice and drowning is a perennial risk in northern communities where winter ice is a defining part of the environment. But to Leary, the four-wheeler accident stuck out as an especially harrowing one, in part because of its timing: It occurred in late March 2019, a time of year when the Kuskokwim River, which runs through Bethel, should be frozen solid and safe for locals to use as a highway to drive from place to place.

“I thought to myself as I was [going] out there — this shouldn’t be happening,” Leary said in an interview. “We should have at least another month of safe travel on river ice.”

Far from an isolated incident, Leary’s experience reflects a reality facing northern communities around the world: As winters grow warmer because of climate change, seasonal lake, river and sea ice is becoming treacherous. Now, a new study is warning

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Shift in atmospheric rivers could affect Antarctic sea ice, glaciers — ScienceDaily

Weather systems responsible for transporting moisture from the tropics to temperate regions in the Southern Hemisphere have been gradually shifting toward the South Pole for the past 40 years, a trend which could lead to increased rates of ice melt in Antarctica, according to new research.

Atmospheric rivers are long, narrow jets of air that carry huge amounts of water vapor from the tropics to Earth’s continents and polar regions. The new study finds atmospheric rivers in the Southern Hemisphere are shifting due in part to ozone depletion, greenhouse gas emissions and natural variations in sea surface temperature.

This shift of atmospheric rivers may affect moisture and heat transported into Antarctica, said Weiming Ma, an atmospheric scientist at UCLA and lead author of the new study published in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.

“The

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Into Thicker Air and Onto Thinner Ice: How Climate Change Is Affecting Mount Everest | Science

Despite being the highest point on Earth, Mount Everest still can’t escape the effects of climate change. The only place that punctures the stratosphere—Everest’s peak reaches 29,035 feet above sea level—has an atmosphere so thin that it leaves mountaineers gasping for breath and glaciers so big that they stretch for miles on end. But both of those elements are changing fast. According to two new studies published today in iScience and One Earth, the air pressure near Everest’s summit is rising, making more oxygen available to breathe, and glaciers are melting at unprecedented rates, leading to more meltwater. The changes will impact climbers scaling the peak and local people who live in the shadow of it.

“Some of the lower Himalayan regions are fairly well studied, but a place like Everest is less studied because it’s just so hard to do work up there.” says Aurora Elmore, a climate scientist

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A better understanding of iceberg melting and lake ice formation could provide new indicators of climate change. — ScienceDaily

Eric Hester has spent the last three years chasing icebergs. A mathematics graduate student at the University of Sydney in Australia, Hester and researchers at Woods Hole Oceanographic Institution in Massachusetts are studying how the shape of an iceberg shapes the way it melts.

“Ice deforms as it melts,” said physical oceanographer Claudia Cenedese, who has worked with Hester on the project. “It makes these very weird shapes, especially on the bottom, like the way the wind shapes a mountain on a longer time scale.”

At the 73rd Annual Meeting of the American Physical Society’s Division of Fluid Dynamics, Hester presented results from his group’s experiments aimed at understanding how melting alters the face-changing boundary of a shrinking iceberg — and how those alterations in turn affect the melting.

The dynamics of iceberg melt is missing from most climate models, Cendese said. Including them could help with prediction: icebergs pump

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Iceberg from Larsen C Ice Shelf threatens penguins on South Georgia Island

Satellite imagery shows the iceberg, shaped like a finger pointed in its direction of travel, headed toward South Georgia Island. It measures about 95 miles in length and 30 miles in width, making it roughly equivalent to the size of the island itself. It is now located less than 300 miles from the island, NASA found.

According to David Long, a Brigham Young University professor who tracks polar ice using satellite imagery, the iceberg is sizable enough that if it becomes grounded in shallow waters off the island’s eastern shore, it could make it difficult for native wildlife to forage for food.

Geraint Tarling, an ecologist at the British Antarctic Survey, said in a news release that the iceberg could have “massive implications” for local species, especially if it is there for a long time.

“When you’re talking about penguins and seals during the period that’s really crucial to them

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NASA’s “Break the Ice” challenge seeks ideas to assist with future moon missions

Harsh lunar conditions present numerous challenges for future astronauts. NASA is seeking innovative solutions to help harvest the moon’s resources.

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image: NASA

By 2024, NASA’s Artemis program is scheduled to land a man and a woman on the lunar surface. To assist with long-term sustained presence on the moon in the years ahead, NASA will need to tap resources in-situ rather than rely on supplies from Earth. It turns out, lunar regolith is brimming with life-supporting potential, but harvesting these materials in the harsh lunar environment presents numerous engineering challenges.

On Wednesday, NASA announced that it was seeking innovative strategies to help the agency excavate lunar regolith and subsequently deliver this material to a theoretical regolith processing plant situated on the moon’s south pole. NASA’s Break the Ice Lunar Challenge is currently open for registration to help the space agency develop capabilities to eventually support a sustained human lunar presence

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