Feed aggregator

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Space Weather 

The solar wind is a continuous stream of charged particles released from the Sun into the solar system. It plays a major role in space weather, which can impact satellites, astronauts, and power systems on Earth. Forecasting the solar wind often depends on detailed maps of the Sun’s magnetic field and complex models of the solar corona, which introduce uncertainty and are not always available.

Owens et al. [2026] present a new approach that uses solar wind measurements near Earth to reconstruct solar wind conditions closer to the Sun. By tracing the solar wind back towards its source, the method provides realistic starting conditions for solar wind models without relying on magnetic maps. The authors show that this approach can produce realistic solar wind conditions while reducing assumptions and sources of error. This simpler set-up allows the method to be applied consistently across different modelling frameworks.

This work represents an important step towards more robust and accessible solar wind modeling. In the long term, it can help improve space weather forecasts and our ability to protect technology and infrastructure in space and on Earth.

Citation: Owens, M. J., Barnard, L. A., Turner, H., Gyeltshen, D., Edward-Inatimi, N., O’Donoghue, J., et al. (2026). Driving dynamical inner-heliosphere models with in situ solar wind observations. Space Weather, 24, e2025SW004675. https://doi.org/10.1029/2025SW004675

—Tanja Amerstorfer, Associate Editor, Space Weather

Text © 2026. 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.

A UT San Antonio-led international research team has identified chitin, the primary organic component of modern crab shells and insect exoskeletons, in trilobite fossils more than 500 million years old, marking the first confirmed detection of the molecule in this extinct group.

Researchers at Kyoto University have proposed a new physical model that explores how disturbances in the ionosphere may exert electrostatic forces within Earth's crust and potentially contribute to the initiation of large earthquakes under specific conditions. The study does not aim to predict earthquakes but rather presents a theoretical mechanism describing how ionospheric charge variations—caused by intense solar activity such as solar flares—could interact with pre-existing fragile structures in Earth's crust and influence fracture processes.

Earth's surface is covered by more than a dozen tectonic plates, and in subduction zones around the world—including the Japanese Islands—plates converge and dense oceanic plates sink into Earth's interior. These regions, especially plate boundaries, are known for frequent seismic activity.

Southern California's beaches have grown more than 500 acres over the past four decades despite being one of the most heavily urbanized and dammed coastal regions in the world, according to a new study conducted by researchers at the University of California, Irvine, the U.S. Geological Survey and other institutions. The conventional wisdom-challenging revelation about coastal erosion and replenishment is the subject of the study published recently in Nature Communications.

Source: Journal of Geophysical Research: Biogeosciences

From 1948 to 1953, a gold mine called Giant Mine released about 5 tons of arsenic trioxide per day into the environment around Yellowknife, Northwest Territories, Canada. Emissions declined from the 1950s until the mine closed in 2004, but the surrounding landscape remains highly contaminated with arsenic.

Little et al. recently studied how the spring thaw influences arsenic levels in four Yellowknife area lakes and how phytoplankton populations alter arsenic biogeochemistry during this transition period. The researchers sampled each lake twice per year in 2022 and 2023: once in late April, before the beginning of the spring thaw period, and once 7–10 days later, when the thaw had begun but the ice was still thick enough to safely walk on, making sample collection feasible.

Sammy’s, Handle, Frame, and Jackfish lakes spanned a gradient of arsenic contamination levels when measured before the thaw in 2022—from 5.5 micrograms per liter in Sammy’s Lake to 350 micrograms per liter in Frame Lake. In Handle, Frame, and Jackfish lakes, arsenic levels went down as the spring thaw began, but Sammy’s Lake followed the opposite trend. The difference likely lies in how much arsenic the lakes contained to begin with. With Sammy’s Lake starting at such a low level, arsenic from meltwater exacerbated the contamination. In the other three lakes, the concentration of arsenic in meltwater was lower than or similar to the starting concentration in the lake, so meltwater diluted the contamination.

Arsenic exists mostly in two oxidation states: arsenite and the less toxic, less mobile arsenate. Because arsenate is more stable under oxic conditions, the influx of highly oxygenated snow and ice meltwater during the spring thaw period was accompanied by a predictable shift in the predominant form of arsenic in the lakes.

The winter of 2022 was significantly colder than 2023, with the difference reflected in the thickness of the ice: 76–130 centimeters in 2022 compared with 65–72 centimeters in 2023. The warm winter did not alter the final arsenic concentration or speciation in the water at the end of the thaw. However, an increase was observed in plankton communities in more mature life stages and in taxa that are more competitive in warmer conditions. This result is important, the authors say, because late winter and spring thaw plankton community dynamics set the stage for the following open-water season. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG009231, 2026)

—Saima May Sidik (@saimamay.bsky.social), Science Writer

Citation: Sidik, S. M. (2026), How the spring thaw influences arsenic levels in lakes, Eos, 107, https://doi.org/10.1029/2026EO260051. Published on 6 February 2026. Text © 2026. 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.

Until 1959, nobody on Earth had ever seen our Moon’s farside. Thanks to gravitational tidal forces, the lunar nearside always faces us, so it was surprising for everyone to learn that the other half of the Moon looks strikingly different. Not only that, but subsequent observations showed the lunar farside has a thicker surface than the nearside, and its rocks have different compositions.

And nobody knows exactly why.

However, some scientists think the solution to the mystery involves a site known as the South Pole–Aitken (SPA) basin, which was created by an asteroid impact early in the solar system’s history. A new study published in the Proceedings of the National Academy of Sciences of the United States of America draws from surface samples returned by the Chang’e-6 (pronounced CHAHNG-ua) robotic probe. The samples contain minuscule differences in chemical and isotopic composition that indicate the ancient impact may have vaporized part of the Moon’s interior, enough to account for the differences between the near- and farsides.

“Chang’e-6 currently provides the only samples returned from the lunar far side,” said planetary geochemist Heng-Ci Tian ( 田恒次) of the Institute of Geology and Geophysics at the Chinese Academy of Sciences, Beijing, in an email to Eos. Comparing these samples to those collected by previous Chang’e probes and the Apollo missions, Tian and his colleagues determined the impact did more than just make a big crater: It reshuffled the geological components of the lunar mantle. In particular, they looked at isotopes of moderately volatile substances such as potassium that vaporize at relatively low temperatures, rather than more abundant, low-mass elements like hydrogen and oxygen.

If this hypothesis holds up under further scrutiny, it would not only tell us about our Moon’s history and origins but help us understand planetary evolution in general.

As with Earth, the Moon’s mantle—the relatively plastic layer of minerals between the crust and core—is the source of the magma that once powered volcanoes. The nearside is marked by ancient volcanic flows, known as “mares” (pronounced MAR-ays) or “seas,” which are largely absent on the farside.

“Our study reveals that the SPA basin impact caused [evaporation] of moderately volatile elements in the lunar mantle,” Tian said. “The loss of these volatile elements likely suppressed magma generation and volcanic eruptions on the far side.”

If this hypothesis holds up under further scrutiny, it would not only tell us about our Moon’s history and origins but help us understand planetary evolution in general. After all, Earth’s surface is constantly renewed by plate tectonics and hydrologic processes, but other worlds such as Mars and Venus are less dynamic, and much of what is going on inside is still mysterious.

“There’s so many uncertainties as to really what happened [when SPA formed] and how it would’ve affected the interior,” said Kelsey Prissel, a planetary scientist at Purdue University in Indiana who was not involved in the study. She pointed out that different geophysical processes like crystallization and evaporation lead to different populations of isotopes. The new study, which shows a larger fraction of certain isotopes in the SPA region than on the lunar nearside, therefore provides strong evidence that the farside mantle was partially vaporized long ago.

“Previous studies have shown that impacts alter the composition and structure of the lunar surface and crust, but our study provides the first evidence that large impacts play an important role in planetary mantle evolution,” Tian said.

It Came from the Farside!

The SPA basin is one of the biggest impact craters in the solar system, so huge it doesn’t even look like a crater: It stretches all the way from the lunar South Pole to the Aitken crater (hence the name) at approximately 16°S latitude. Researchers determined it formed about 4.3 billion years ago—not long, in cosmic terms, after the Moon was born. Interestingly, it is also almost directly antipodal to a cluster of volcanoes on the lunar nearside, which suggested to some scientists the features might be related.

However, the farside is harder to study. Humanity’s first view came only in 1959 with the uncrewed Soviet Luna 3 orbiter, and none of the Apollo missions landed there. Robotic spacecraft have mapped the entire Moon in detail, but the Chang’e-4 probe achieved humanity’s first farside landing in 2019. Chang’e-6 landed in the SPA basin on 1 June 2024 and returned the first (and so far only) samples from the lunar farside to Earth on 25 June.

“[If] you looked at this data 20 years ago, [the samples] would all look the same.”

The next phase in the study was comparing the chemical makeup and isotopes in these rocks to their nearside counterparts collected by the Apollo astronauts and the Chang’e-5 mission. In particular, Tian and his colleagues looked at potassium (K), rare-earth elements, and phosphorous, collectively known as KREEP, which are possibly related to mantle composition. As the researchers noted in their paper, if the SPA impact vaporized materials in the Moon’s mantle, it might also have redistributed KREEP-rich minerals from the farside to the nearside. Testing this hypothesis required doing very sensitive laboratory measurements that weren’t possible in the Apollo era.

“Having the far side samples is brand-new no matter what,” Prissel said. “But looking at these really fine differences between isotopes is something we haven’t been able to do forever. [If] you looked at this data 20 years ago, [the samples] would all look the same.”

Prissel’s point highlights the interdependency of different branches of planetary science: Understanding the Moon’s interior requires studying samples, performing laboratory experiments on them (or on analog materials), and running theoretical models. These new results will inform the next set of experiments and modeling, as well as guide future lunar sample return missions.

“We plan to analyze additional volatile isotopes to verify our conclusions,” Tian said. “We will combine these with numerical modeling to further evaluate the global effects of the SPA impact.”

—Matthew R. Francis (@BowlerHatScience.org), Science Writer

Citation: Francis, M. R. (2026), Primordial impact may explain why the Moon is asymmetrical, Eos, 107, https://doi.org/10.1029/2026EO260050. Published on 6 February 2026. Text © 2026. 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.

A new study led by Prof. Xiao Wenjiao from the Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences sheds light on the ore-forming process and key mechanisms of the gold deposit in the South Tianshan of northwest China. The research was published in the Geological Society of America Bulletin on Jan. 20.

Imagery is now available that shows the aftermath of 3.1 km long landslide that killed about 90 people in West Bandung.

On 24 January 2026, a major landslide occurred on the flanks of Gunung Burangrang (Mount Burangrang) in West Bandung, Indonesia. The search has been long and painstaking, but it is thought that 92 people were killed. There were 23 reported survivors.

AFA Channel has posted some very good drone footage of the landslide to Youtube (excuse the dramatic music and the incorrect headline):-

Planet Labs have also captured a good satellite image of the site. I have overlain this onto the Google Earth DEM:-

Satellite image of the 24 January 2026 landslide on Gunung Burangrang in Indonesia. Image copyright Planet Labs, used with permission.

By way of comparison, this is the site prior to the landslide (image from February 2025):-

Google Earth image of the site of the 24 January 2026 landslide on Gunung Burangrang in Indonesia.

And here is a slider to allow a comparison between the images:-

This appears to have been a deep-seated, probably structurally-controlled failure on high, very steep slopes of Gunung Burangrang, which has then transitioned into a channelised flow. There is considerable entrainment along the track. The landslide is about 3.1 km long and up to 150 m wide.

There has been considerable discussion in Indonesia about the role of logging and mining in the causation of these large landslide events, but in this case neither are apparent in the source area. Institut Teknologi Bandung has a nice article about causation of this landslide, which notes that the underlying geology is volcanic. Loyal readers of this blog will recognise the frequency with which intense rainfall triggers devastating landslides in volcanic materials.

Acknowledgement

Many thanks to the wonderful people at Planet Labs for providing access to the satellite imagery.

Return to The Landslide Blog homepage Text © 2026. 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.

The magnitude 6.9 earthquake that took place in 2018 on the south flank of Kīlauea on the Island of Hawaiʻi may have stalled episodes of periodic slow slip along a major fault underlying the volcano, according to a new study by scientists at the U.S. Geological Survey.

A research team led by Prof. Xiao Kai from the Yantai Institute of Coastal Zone Research of the Chinese Academy of Sciences has systematically elucidated the transformation and transport processes of nutrients in intertidal groundwater. The team employed a combined methodological approach, including multi-depth groundwater sampling, dynamic monitoring, stable isotope tracing, and multivariate statistical analysis. Their findings, published in the Journal of Hydrology, provide scientific evidence to deepen understanding of the terrestrial drivers of nearshore eutrophication.

Publication date: 1 February 2026

Source: Advances in Space Research, Volume 77, Issue 3

Author(s): Alberto Regadío, Juan José Blanco, J. Ignacio García Tejedor, Carlo Luis Guerrero, Du Toit Strauss

Publication date: 1 February 2026

Source: Advances in Space Research, Volume 77, Issue 3

Author(s): Shakir Ullah, Abdullah Alshehab, Muhammad Shohaib, Huda Alfannakh, Najeh Rekik

Stanford researchers have created the first-ever global map of a rare earthquake type that occurs not in Earth's crust but in our planet's mantle, the layer sandwiched between the thin crust and Earth's molten core. The new map will help scientists learn more about the mechanics of mantle earthquakes, in turn opening a window into the complexities and triggers for all earthquakes.

A combination of weakened atmospheric removal and increased emissions from warming wetlands, rivers, lakes, and agricultural land increased atmospheric methane at an unprecedented rate in the early 2020s, an international team of researchers report today in the journal Science.

In the Pacific Northwest, big faults like the Cascadian subduction zone located offshore, get a lot of attention. But big faults aren't the only ones that pose significant hazards, and a new study investigates the dynamics of a complex fault zone that runs right under the heart of Seattle.

Scientists at the University of Southampton have uncovered evidence from ancient rocks that Earth's climate continued to fluctuate during its most extreme ice age—known as Snowball Earth. During the Cryogenian Period, between 720 and 635 million years ago, it has long been believed that Earth's climate entirely shut down.

Every year at Grand Canyon National Park, millions of visitors from all over the world stop at one of a dozen water spigots. Most people are on a rim, seeing the canyon's majesty for the first time, when they step off the trail to refill a water bottle. Others are deep in the belly of the canyon, sweaty and tired, facing a hike up in punishing heat, filling their reservoirs and dumping water over their heads to avoid dehydration and heat stroke.

Global climate models capture many of the processes that shape Earth's weather and climate. Based on physics, chemistry, fluid motion and observed data, hundreds of these models agree that more carbon dioxide in the atmosphere leads to hotter global temperatures and more extreme weather. Still, uncertainty remains around how seasonal weather patterns and atmospheric systems like the jet stream will respond to global warming. Some of this uncertainty stems from the way models approximate the effects of relatively short-lived, small-scale phenomena known as gravity waves.

Seamounts and the oxygen minimum zone (OMZ) are two typical deep-sea habitats that often coexist. However, determining whether the "seamount effect" alters OMZ structure through marine stratification, thereby influencing the deep-sea hypoxic environment and carbon sink processes, remains unconfirmed.