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One billion years ago, a meteorite struck Scotland and influenced life on Earth

Phys.org: Earth science - Tue, 04/29/2025 - 16:29
We've discovered that a meteorite struck northwest Scotland 1 billion years ago, 200 million years later than previously thought. Our results are published today in the journal Geology.

Scientists discover surface carbonates can transport heavy boron isotopes into deep mantle

Phys.org: Earth science - Tue, 04/29/2025 - 14:33
Volatiles are crucial for sustaining life and Earth's habitability, with subduction zones being the main pathways for these materials to enter the mantle. However, the devolatilization of subducting slabs may impede the recycling of volatiles like carbon. Boron, a moderately volatile element with strong fluid mobility, serves as a useful tracer for tracking the recycling of volatiles through its isotopic composition (δ¹¹B).

Billion-year-old impact in Scotland sparks questions about life on land

Phys.org: Earth science - Tue, 04/29/2025 - 13:45
New Curtin University research has revealed that a massive meteorite struck northwestern Scotland about 200 million years later than previously thought, in a discovery that not only rewrites Scotland's geological history but alters our understanding of the evolution of non-marine life on Earth.

Rainfall patterns found to trigger extreme humid heat in tropics and subtropics

Phys.org: Earth science - Tue, 04/29/2025 - 09:00
Scientists believe they have found a way to improve warning systems for vulnerable communities threatened by humid heat waves, which are on the rise due to climate change and can be damaging and even fatal to human health.

Noto quake 3D model adds dimension to understand earthquake dynamics

Phys.org: Earth science - Tue, 04/29/2025 - 00:00
On New Year's Day 2024, a massive 7.5-magnitude earthquake struck the Noto Peninsula in north central Japan, resulting in extensive damage in the region caused by uplift, when the land rises due to shifting tectonic plates. The observed uplift, however, varied significantly, with some areas experiencing as much as a 5-meter rise in the ground surface.

High-resolution climate models reveal how Tasman Sea temperatures may influence Antarctic peninsula warming

Phys.org: Earth science - Mon, 04/28/2025 - 21:14
The Antarctic Peninsula, one of the fastest-warming regions on Earth, has seen temperatures rise five times faster than the global average in recent decades. Extreme heat events, such as the record-breaking 20.8° C recorded at Seymour Island in February 2020, have raised urgent questions about the drivers behind these dramatic changes.

Climate change drives more overlapping wildfire seasons in Australia and North America, study finds

Phys.org: Earth science - Mon, 04/28/2025 - 21:12
Climate change is increasing the risk of wildfires in many regions of the world. This is due partly to specific weather conditions—known as fire weather—that facilitate the spread of wildfires.

NASA 3D wind-measuring laser aims to improve forecasts from air, space

Phys.org: Earth science - Mon, 04/28/2025 - 20:47
Since last fall, NASA scientists have flown an advanced 3D Doppler wind lidar instrument across the United States to collect nearly 100 hours of data—including a flight through a hurricane. The goal? To demonstrate the unique capability of the Aerosol Wind Profiler (AWP) instrument to gather extremely precise measurements of wind direction, wind speed, and aerosol concentration—all crucial elements for accurate weather forecasting.

Snowball Earth: Drone mapping and isotopic dating suggest Marinoan glaciation spanned 4 million years

Phys.org: Earth science - Mon, 04/28/2025 - 20:20
Scientists at the University of California, Berkeley, and Boise State University have found evidence suggesting that the Marinoan glaciation began approximately 639 million years ago and lasted for approximately 4 million years. In their study published in the Proceedings of the National Academy of Sciences, the group used drone and field imagery along with isotopic dating of glacial deposits to learn more about global glaciation events during the Neoproterozoic Era.

Anatomy of a 'zombie' volcano: Investigating the cause of unrest inside Uturuncu

Phys.org: Earth science - Mon, 04/28/2025 - 19:00
Scientists from China, the UK and the U.S. have collaborated to analyze the inner workings of Bolivia's "zombie" volcano, Uturuncu. By combining seismology, physics models and analysis of rock composition, researchers identify the causes of Uturuncu's unrest, alleviating fears of an imminent eruption. The findings have been published in the journal PNAS.

Earthquake-driven land sinking could increase flood risk in Pacific Northwest

Phys.org: Earth science - Mon, 04/28/2025 - 19:00
The next great earthquake isn't the only threat to the Pacific Northwest. A powerful earthquake, combined with rising sea levels, could significantly increase flood risks in the Pacific Northwest, impacting thousands of residents and properties in northern California, Oregon, and Washington, according to new Virginia Tech research.

Glaciers offer clues into the path of fossil fuel pollution

Phys.org: Earth science - Mon, 04/28/2025 - 18:24
Glaciers provide a unique opportunity for researchers to measure levels of atmospheric carbon deposition. Unlike other terrestrial ecosystems, these slow-moving rivers of ice do not have other large reservoirs of soil or vegetation that might obscure how much carbon they receive from the atmosphere.

Humanity's recent history leaves marks in deep marine sediments

Phys.org: Earth science - Mon, 04/28/2025 - 18:22
Research led by the Spanish Institute of Oceanography (IEO-CSIC), with the participation of the Universitat Autònoma de Barcelona and the Institute of Marine Sciences (ICM-CSIC), has reconstructed the history of pollution in the seabed of the Cantabrian Sea and the northwestern Mediterranean over the past centuries.

Granular systems, such as sandpiles or rockslides: New research will help scientists describe how they work

Phys.org: Earth science - Mon, 04/28/2025 - 17:15
Did you eat cereal this morning? Or have you walked on a gravel path? Maybe you had a headache and had to take a pill? If you answered any of these questions with a yes, you interacted with a granular system today.

Extreme rainfall—a long-standing hypothesis on temperature dependence may finally be settled

Phys.org: Earth science - Mon, 04/28/2025 - 17:09
Flash floods resulting from extreme rainfall pose a major risk to people and infrastructure, especially in urban areas. Higher temperatures due to global climate change affect continuous rainfall and short rain showers in somewhat equal measure.

Industrial waste is turning to rock in just decades, research reveals

Phys.org: Earth science - Mon, 04/28/2025 - 13:59
An aluminum tab from a drinks can found encased in a new form of rock on the Cumbrian coastline has helped provide scientists with a shocking new insight into the impact of human activity on Earth's natural processes and materials.

Tropical mountain ice cores help decipher climate riddles in Earth's history

Phys.org: Earth science - Mon, 04/28/2025 - 13:44
Scientists are working to shed new light on an enduring climate mystery—one that, if solved, could help them make more accurate predictions about the planet's future.

Geoengineering technique could cool planet using existing aircraft

Phys.org: Earth science - Mon, 04/28/2025 - 13:00
A technique to cool the planet, in which particles are added to the atmosphere to reflect sunlight, would not require developing special aircraft but could be achieved using existing large planes, according to a new modeling study led by UCL (University College London) researchers.

A Geologic Map of the Asteroid Belt

EOS - Mon, 04/28/2025 - 12:59

Where do meteorites come from? A new analysis of 75 fall events suggests that meteorites with different geologies travel from different places in the asteroid belt, which separates Mars and Jupiter. Researchers traced some types of meteorites to particular asteroid families, creating a geologic map of meteorite origins. Most meteorites were generated by just a few recent collisions between asteroids.

“Understanding the asteroid belt is really looking into the past, into the formation of the solar system, and into all the dynamics that happened at that time,” said Peter Jenniskens, coauthor on the new analysis and a meteorite astronomer at the SETI Institute in Mountain View, Calif. Those early interactions and collisions matter because much of the water on Earth and a lot of the organics likely came from primitive asteroids, he added.

Tracking Falls

Spacecraft have returned small volumes of material from the Moon, comets, and asteroids, but meteorites remain the primary way that scientists get their hands on space rocks.

“By reconstructing where specific meteorite types formed, we gain a clearer picture of the compositional and thermal gradients that existed when the solar system was young,” said Michaël Marsset, an astronomer at the European Southern Observatory in Santiago, Chile. “This has major implications for understanding how habitable environments emerge, not just here but potentially in other planetary systems as well.” Marsset studies small solar system objects and Earth impactors and was not involved in the new study.

But matching a meteorite to the asteroid it came from is a tall task.

“Asteroids in space look quite a bit different than the meteorites that we have in our laboratories.”

“Asteroids in space look quite a bit different than the meteorites that we have in our laboratories, because the asteroids in space are covered by regolith and debris and they are exposed to solar radiation and solar wind,” Jenniskens said. A meteorite might come from an asteroid’s interior, which could look entirely different from its surface. That makes it challenging to use astronomical observations alone to match meteorites to their asteroid parents.

When someone witnesses a meteorite falling to Earth, scientists can try to backtrack its orbit to a point of origin. Combining this information with the meteorite’s geochemistry, mineralogical structure, and age, they can then figure out which asteroid or asteroid family—a group of asteroids that originate from the same collision event—sent it hurtling toward Earth.

The trouble is that meteorites fall more or less at random, Jenniskens explained. It has taken a while to document enough falls to spot patterns, he said. Just 6 years ago, there were fewer than 40 meteorite falls with well-measured trajectories.

“The number of falls has doubled since that time,” Jenniskens said.

Meteorite researchers have set up more than 2 dozen global camera networks that have detected many of these recent falls—roughly 14 falls per year. Also, the rising popularity of dash cameras and doorbell cameras has contributed to the surge of recent detections.

In the new analysis, about 36 of the 75 falls were recorded by residential security cameras, Jenniskens said. People report fireball sightings and submit videos for analysis. “We really depend on the citizen science.”

Meteorite Ancestry

Jenniskens and his colleague Hadrien Devillepoix of Curtin University in Perth, Australia, reviewed the trajectories, geochemistry, mineralogy, and size of 75 meteorites. They also looked at the meteorites’ ages, calculated on the basis of how long a rock’s surface has been exposed to cosmic rays.

Though a few asteroids are suspected sources of certain meteorite types, a meteorite’s age was often the key factor in figuring out which asteroid family produced the meteorite. The positions and movements of asteroids within a family evolve in a predictable way over time, and if this so-called dynamical age matched a meteorite’s cosmic ray age, that family was more likely to be the meteorite’s source.

NASA’s Dawn spacecraft orbited asteroid 4 Vesta and mapped its surface geology and chemistry. Debris from impacts that made some of these craters makes it way to Earth as HED meteorites. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA, Public Domain

Most of the meteorites originated from a handful of asteroid families, and different classes of meteorites could be traced to different parts of the asteroid belt.

Jenniskens and Devillepoix confirmed that very low iron LL-type meteorites, such as the Chelyabinsk meteorite, originated from the extensive Flora family in the inner asteroid belt. They tracked H-type chondrites to debris clusters in the Koronis, Massalia, and Nele families. They also traced low-iron L chondrites to the Hertha asteroid family, rather than to the previously determined Massalia family.

“Hertha is covered by dark rocks that were shock blackened, indicative of an unusually violent collision,” Jenniskens said. “The L chondrites experienced a very violent origin 468 million years ago when these meteorites showered Earth in such numbers that they can be found in the geologic record.”

“It turns out that, yes, our HED meteorites seem to come from Vesta, not from its family.”

Marsset has also worked to trace meteorites to their asteroid origins, though his team used astronomical observations of asteroids and numeral modeling, rather than meteorite data. “Even with these different approaches, we’re mostly converging on similar conclusions,” Marsset said. “Where we disagree, well, that’s part of the fun! For example, I’d gladly bet a pint with Dr. Jenniskens and Dr. Devillepoix that L chondrites come from the Massalia family, not Hertha,” he joked.

The team also looked at howardite, eucrite, and diogenite (HED) meteorites, achondrites that have long been tied to the Vesta asteroid family. According to the new analysis, the volume of HED material that made its way to Earth must have come from a collision so large that only something as large as Vesta would have survived. (Vesta is the second-largest object in the asteroid belt.) What’s more, the cosmic ray exposure ages of HED meteorites closely match the ages of particular impact craters on Vesta’s surface that were mapped by NASA’s Dawn spacecraft.

“It turns out that, yes, our HED meteorites seem to come from Vesta, not from its family,” Jenniskens said.

Decoding Solar System History

“What’s remarkable about this work is the broader picture it starts to paint,” Marsset said. “We are finally able to map specific classes of meteorites that fall on Earth to distinct regions in the asteroid belt and to specific asteroid families.… That’s a major step toward understanding the compositional structure of the asteroid belt and, ultimately, how our solar system formed and evolved.”

But it’s just as important to understand where meteorites aren’t coming from, he pointed out.

“While one might expect the meteorite flux to represent a broad sampling of material from across the entire asteroid belt, we now know that it is actually dominated by a few recent fragmentation events,” Marsset said. “This insight helps us better understand the natural sampling bias in the meteorites we collect on Earth, and it also highlights which asteroid populations are underrepresented. That, in turn, can guide the targets of future space missions aimed at filling in those missing pieces.”

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

Citation: Cartier, K. M. S. (2025), A geologic map of the asteroid belt, Eos, 106, https://doi.org/10.1029/2025EO250165. Published on 28 April 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Glaciers Offer Clues into the Path of Fossil Fuel Pollution

EOS - Mon, 04/28/2025 - 12:58
Source: Global Biogeochemical Cycles

Glaciers provide a unique opportunity for researchers to measure levels of atmospheric carbon deposition. Unlike other terrestrial ecosystems, these slow-moving rivers of ice do not have other large reservoirs of soil or vegetation that might obscure how much carbon they receive from the atmosphere.

In most terrestrial ecosystems, dissolved organic matter comes from plants and soil and can contain both organic carbon and black carbon (the sooty black product from wildfires and burning fossil fuels). In glaciers, organic matter is predominately derived from in situ microbial production and atmospheric deposition. Both can contribute to downstream food webs and broader biogeochemical cycling.

Understanding how glaciers get their carbon, including how much comes from atmospheric deposition, can help scientists understand how human activity affects the glacier carbon cycle and ecosystems.

Holt et al. investigated dissolved organic matter in the meltwater from 10 glaciers across Alaska, Switzerland, Kyrgyzstan, and Ecuador. By examining dissolved organic carbon and black carbon isotopes, as well as molecular-level composition, researchers found that anthropogenic pollutants significantly influenced the composition of dissolved organic matter in glaciers and that this influence varied by region.

The researchers collected samples from each glacier outflow stream and determined the age of the dissolved organic carbon in the samples. These ages offered an isotopic signature of their sources. For instance, younger samples might originate from wildfire material and microbial activity on the glacier surface, whereas older material more likely originated from ancient carbon sources, namely, fossil fuels.

Each region displayed different amounts of dissolved organic carbon linked to anthropogenic atmospheric pollution, ranging from 12% to 91%, with a median of 50%. Carbon from fossil fuels was more prevalent in the dissolved organic matter of the Alaskan glacier. In Ecuador, there was a higher relative contribution of carbon from biomass burning, such as wildfires, and in situ microbial activity. The exact source, age, and makeup of dissolved organic carbon and dissolved black carbon varied between different glaciers outflows. But overall, the researchers say, fossil fuels are affecting the carbon content in glacier outflow globally, with implications for the ecosystems that depend on them. (Global Biogeochemical Cycles, https://doi.org/10.1029/2024GB008359, 2025)

—Rebecca Owen (@beccapox.bsky.social), Science Writer

Citation: Owen, R. (2025), Glaciers offer clues into the path of fossil fuel pollution, Eos, 106, https://doi.org/10.1029/2025EO250161. Published on 28 April 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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