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Some of the most extraordinary gems ever found belong to a rare class of diamonds known as CLIPPIRs (Cullinan-like, Large, Inclusion-Poor, Pure, Irregular, Resorbed). They make up less than 1% of all diamonds on Earth and include three of the largest diamonds ever recovered: the Cullinan, at 3,106 carats (1.4 pounds), found at the Premier mine in South Africa; the 1,111-carat Lesedi La Rona, discovered at the Karowe mine in Botswana in 2015 and sold for $53 million in 2017; and the 2,492-carat Motswedi (1.1 pounds), recovered from the Karowe mine in 2024.

The Great Salt Lake is separated by a 20-mile (32-kilometer) causeway into a super-salty north arm and a less-salty south arm, with each hosting distinct communities of extremophiles. These organisms mingle at a gap in the causeway, designed to regulate salinity, that has provided microbiologists with an unusual and rich opportunity to study how human activities and weather disturbances affect microbial communities in extreme environments.

Source: Community Science

When a local community gets involved in environmental monitoring, their efforts can build awareness of local environmental issues and provide more plentiful data than scientists can collect on their own. But how does the quality of the data compare to readings taken by professionals?

The state of Bihar, India, was the perfect place to find out. More than 90% of the population relies on groundwater for cooking and cleaning, but at times, that same groundwater has been reported to be contaminated with arsenic, iron, manganese, nitrate, and uranium, all of which can cause health problems. Richards et al. compared the results of community members’ efforts to monitor groundwater for contaminants with those of professional scientists.

The researchers recruited community members who were affiliated with one secondary school, three colleges, and one professional institution. Many participants were teenage students, but some were adult employees of the schools. All told, the team included 583 people. The participants collected water samples from places people access water during their daily lives, such as hand pumps that supply drinking water. The research team brought the samples back to the University of Manchester on commercial flights, then analyzed the samples at the Manchester Analytical Geochemistry Unit laboratories.

The results were broadly similar to those collected by professional scientists, showing that participatory science is an excellent way to increase the amount of data environmental scientists have to work with, the authors say. With more data, scientists can spot spatial patterns that might be overlooked with a smaller workforce. Participatory science can also generate interest in research, potentially bringing more women and minorities into the field. (Community Science, https://doi.org/10.1029/2025CSJ000136, 2026)

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

Citation: Sidik, S. M. (2026), Students enable widespread water monitoring in India, Eos, 107, https://doi.org/10.1029/2026EO260233. Published on 20 July 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.

AI companies increasingly want to move their operations into space. Elon Musk's SpaceX has applied to launch over a million AI data center satellites and ultimately build them on the moon.

Africa is home to around 70% of the world's burned area—the total area of land scorched by wildfires each year—making it the planet's biggest wildfire hotspot. Yet despite this, satellite observations have revealed an unexpected trend over the past two decades: The amount of land burned across the continent has been steadily falling.

A floating research station resembling a giant aluminum igloo on Sunday set out from France to begin a long-term mission in the Arctic that will see it drift with the polar ice in one of the most hostile environments.

Reports suggest 42 people were killed in a large rockslope failure. Imagery suggests that suspicion will fall on a cutting at the foot of the slope.

On Friday 17 July 2026, at 9:08 am local time, a large landslide occurred on the banks of the Wujiang River at Hanjia, located within of Pengshui Miao and Tujia Autonomous County in Chongqing, China. Media reports indicate that 42 people have been killed. Ten people were rescued.

Xinhua has released this image of the aftermath of the landslide:-

The aftermath of the 17 July 2026 landslide at Hanjia in Chongqing, China. Image from Xinhua.

There is some dramatic footage of the landslide in action and the immediate aftermath:-

The location of this landslide appears to be [29.27760, 108.16604]:-

Google Earth image of the site of the 17 July 2026 landslide at Hanjia in Chongqing, China.

The images and video suggest that this was a rockslope failure – note the size of the blocks – with a strong element of toppling. The very planar form of the rear scarp suggests to me that release has come from an existing joint or fault.

The media reports indicate that rainfall was the final trigger – this makes sense from a timing perspective – but the focus might be on the underlying causes. My attention is immediately drawn to the building beside the road on the slope side of the site. It appears that the slope has been cut to create the space for the building. The building was under construction in 2014, but this image from 2017 shows the cut more clearly. I have annotated the top of the cut slope:-

Annotated Google Earth image from 2018 showing the site of the 17 July 2026 landslide at Hanjia in Chongqing, China.

This would be my starting point in terms of likely causation of this landslide. Interestingly, there are other locations along this road with large cut slopes, so an immediate priority will need to be an assessment of the stability of those sites.

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.

SummaryAnomalous medium-scale gravity gradient changes reported prior to the 2011 $\rm M_w$ 9.0 Tohoku and the 2010 $\rm M_w$ 8.8 Maule earthquakes have been attributed to transient extensional deformations of the subducting slabs at depths of ~150–300 km. With a regional-scale extent and weak associated surface displacements, these signals and their deformation sources are not well understood. Our aim here is to improve their modelling by taking into account the 3D elastic structure of the subduction zone, and by assessing how the surface observables respond to variations in the spatial distribution and the depth of the deformation source. Taking the case of the pre-Tohoku signals, and representing slab extension with ensembles of dislocations, we investigate the corresponding gravitational and surface displacement signals using fully three-dimensional spectral-infinite-element simulations implemented in the numerical code SPECFEM-X, incorporating a realistic subduction-zone geometry. For the considered deep deformations, our results show a limited impact of the lateral elastic structure on the surface displacement and geoid signals, which differ by less than ~2% and ~3% respectively from the purely radially layered case. The degree of the spatial distribution of the deformation and the depth more strongly impact the relative amplitudes and the smoothness of the gravity and surface displacement signals. Broadly distributed slab deformation leads to a reduction in the extremum amplitude of the vertical surface displacements by up to ~40% compared to the results obtained for highly localized slab deformation of similar magnitude, whereas the amplitude of the medium-scale gravity gradient signals decreases by ≤20% only. These surface displacement and gravity gradient signals are attenuated by ~90% and ~60%, respectively, when moving the source depth from 100 to 500 km. In all cases, broader-scale gravity gradient signals are obtained. Thus, while distributed deformations contribute to smoothing the gravity signals and reducing the amplitude of the corresponding surface displacements, they still do not account for the required sub-centimetric level of ground motions. Our results finally provide a quantitative framework for interpreting intermediate-scale GRACE pre-seismic anomalies at subduction zones.

SummaryThe origins of the diverse Mesozoic magmatism and present-day intraplate seismicity in central Brazil, part of the South American plate currently undergoing compression/shortening, have been the subjects of long-standing debate. Here, we investigate the structure of the lithosphere using a combined three-dimensional (3D) electrical resistivity and seismic P-wave velocity (Vp) tomography to understand the deformation patterns and the relationship to the distribution of magmatism and seismicity in the region. Magnetotelluric and geomagnetic depth sounding data and P-wave travel times from seismological arrays were inverted for the 3D resistivity and Vp variations in the ∼1500 × 1000 km2 area of study. The results reveal a basic structure consisting of an electrically resistive and seismically fast upper crust, a low-resistivity and low-wavespeed lower crust, a resistive and fast uppermost mantle and a basal low-resistivity and low-wavespeed asthenosphere. This layering is thinned in places and dissected by steep cross-cutting NE-SW and NW-SE shear-zones of low resistivity and slow wavespeeds yielding a fragmented lithosphere. Thick blocks of high resistivity and fast wavespeed bounded by the steep shear-zones correlate spatially with zones of gravity lows across the Neoproterozoic fold belts. The steep shear-zones correlate with the Middle Proterozoic and Mesozoic mafic dyke swarms (likely emplaced during the opening of Neoproterozoic and younger proto-Atlantic oceans) and Cretaceous-Eocene alkaline and alkaline-carbonatite magmatism, indicating that inherited structures controlled the lithospheric deformation and magmatism. They also correlate spatially with zones of high seismicity, suggesting that fluid migration plays a role in generating the ongoing seismicity.

SummaryThe buried Nawa Domain of the Gawler Craton, Australia, remains poorly understood, with its deep structure and connections to adjacent terranes largely unknown. We apply a trans-dimensional Bayesian joint inversion of receiver functions and surface wave dispersion along the Marla line, a dense passive seismic array that crosses the craton margin, to image a two-dimensional shear wave velocity profile across over 200 km distance and down to 60 km depth. Our model reveals two low-velocity anomalies: within the craton, where Vs is reduced by about 6 per cent, possibly from fault-related fracturing and elevated heat flow; and at the craton margin, where a 7 per cent low-velocity anomaly spans the crust and extends into the upper mantle, likely linked to the Norwest Fault and thick sediments. Moreover, an increased Vp/Vs ratio near the Norwest Fault, generally above the profile median and locally reaching high values of about 1.80–1.85, provides evidence for mantle-derived fluid migration. The Vs model also reveals Moho shallowing by 10-15 km toward the craton margin, from about 50 km beneath the craton interior to 35-40 km beneath the basin. Edge-driven convection caused by lithospheric steps may drive mantle migration along faults and Moho uplift.

SummaryThe Turkey earthquake on February 6, 2023, Mw7.8 and Mw7.6, generated substantial concern about its effect on regional seismicity, especially in neighbouring Iran. Iran is located at the intersection of many major tectonic plates, including the Arabian, Eurasian, and Indian plates. This complex tectonic environment produces a high frequency of seismic activity, making it critical to understand how major earthquakes affect the behaviour of faults in the region. The study examines the dynamic triggering of seismicity in Iran following the Turkish earthquakes using seismic waveform and catalogue data. The bandpass filter, STA/LTA detection, β-statistics, and matched filter technique were used to analyse continuous waveform data of 99 seismic stations (IIEES, IRSC and AZAR networks) to detect small triggered seismic events. This study examines these earthquakes' effects on the Iranian plateau’s seismic patterns, including the potential for dynamic stress transfer and future seismic activity. We observed that tremors and earthquakes occurred at 14 stations. Six stations in the Persian Block, five stations in the Main Recent Fault zone, and one station each in eastern, southeast Iran, western Alborz and central Iran recorded dynamically triggered seismic activity. The triggered earthquakes were located at hypocentral distances of approximately 20 to 200 km relative to the recording stations. The triggered stations are largely concentrated around regions with high concentration of hot springs which implies that crustal fluids can raise pore pressure and contribute to the occurrence of delayed seismic events. Following the Mw7.8 mainshock, there was a rapid increase in the seismic activity and it continued for ∼5 hours before returning back to the background level. The second large event Mw7.6 did not cause any triggering. These observations imply that transitory seismic activation in Iran occurs through dynamic stress transfer. In addition, the findings suggest that subsurface fluids would have been crucial to delayed triggering events, especially in fluid-rich fault zones. This work shows the importance of remote dynamic triggering in Iran’s tectonically complicated and seismically active areas.

SummarySeismic ambient-noise horizontal-to-vertical spectral ratios (H/V, HVSR) are widely used to characterise near-surface structure and to identify site resonant frequencies. In this article, we propose a nonparametric statistical descriptor of ambient-noise HVSRs. In single-station practice, HVSR curves are typically represented by the geometric mean of window-wise ratios at each frequency, i.e., by the median of a lognormal model. However, distributions of window ensembles are frequently skewed or multimodal. The lognormal median and symmetric uncertainty bands can then depart from the most probable amplitudes and distort the spread. The lognormal mode can mitigate this bias in near-lognormal cases, but it remains tied to a unimodal parametric form. As a consequence, many workflows rely on strict window selection or rejection to justify lognormal assumption. To address this problem, we present a data-driven, nonparametric alternative that provides a marked improvement when ensembles deviate from lognormality. At each frequency, we estimate the probability density of the log-amplitude distribution using kernel density estimation (KDE), transform it to linear space, and take the mode of the linear-domain density as the representative curve. Uncertainty is quantified by highest-density intervals (HDIs), which naturally accommodate asymmetry and multi-branch distributions. Using an example of a near-lognormal microtremor, we demonstrate that the KDE mode closely tracks the lognormal mode while revealing a systematic upward shift of the commonly used lognormal median. Using a microtremor at a structurally complex site, we observe strongly multimodal amplitude and directional statistics. Both the lognormal-median and lognormal-mode curves fall between competing modes. However, the KDE-based modes and intervals follow the dominant branches and capture multimodal spread. Because the density is inferred directly from window-wise data, the method reduces the need for strong window rejection. We also compare the KDE-mode descriptor with the energy-ratio estimator which averages horizontal and vertical component energies before taking their ratio. Agreement between the energy-ratio estimator and the KDE mode is consistent with a stable single HVSR population, whereas discrepancies help identify frequency bands affected by multimodality, non-stationarity or directional effects. Finally, we extend the same framework to directional HVSR using the horizontal spectral matrix and quantify directional variability through a $\pi $-periodic circular KDE of the axial principal horizontal directions. We show that KDE-based modes, highest-density intervals and directional spread provide robust distribution-aware observational diagnostics that can guide data selection, uncertainty assignment and frequency weighting in site-characterisation and inversion workflows.

A new review in Limnology and Oceanography led by scientists at UC San Diego's Scripps Institution of Oceanography warns that the rapid loss of oxygen from the ocean and other aquatic ecosystems is pushing Earth toward an "unsafe space," with consequences that could be irreversible on human timescales.

Alberto Borges, oceanographer at the University of Liège, has conducted a comparative study in Belgium and Africa on the microbial oxidation of methane in rivers, a natural process in which certain bacteria consume this powerful greenhouse gas before it is released into the atmosphere. His research reveals that this biological filter, which is more active in African rivers than in Belgian rivers, remains insufficient to offset the rise in methane emissions expected because of global warming and nitrate pollution.

Wetlands are the largest natural source of methane on Earth. Though the waterlogged lands offer benefits that include hosting thriving ecosystems and protecting our shorelines from flooding, researchers are eager to better understand their contribution to the warming climate.

Researchers report that typical global wetlands surveys overlook an astronomical number of small wetlands: about 160 million of them.

In a paper published in Nature Climate Change, researchers report that typical global wetlands surveys overlook an astronomical number of small wetlands: about 160 million of them.

These small wetlands, which range in size from a large swimming pool to 100 hectares (250 acres), are responsible for 25% of the present global methane emissions, the research found. The results also revealed that these methane emissions increased by 9.9% from 2003 to 2022. This increase reflected both a growing number of small wetlands and climatic changes that spurred them to generate more emissions.

The work shows our current grasp on these environments is woefully incomplete.

The new research “points to the strong need to study these ecosystems further,” said Kyle Delwiche, a biogeochemical scientist at the University of California, Berkeley, who was not involved with the research.

Methane Mania

Wetlands come in myriad flavors and are found on every continent except Antarctica. Groundwater feeds peat-rich bogs and fens in places like Scotland and Scandinavia, and the Amazon and Congo Rivers support sprawling, forested swamps. Though the mechanisms underlying each wetland differ, the environments are united by a group of methane-producing microbes that thrive in their oxygen-starved soils.

Researchers have long known wetlands are major sources of global methane, a greenhouse gas with significantly more near-term warming potential for our climate than carbon dioxide. But quantifying these wetlands to assess their emissions is no simple task.

To study wetlands on a global scale, researchers typically use coarse-resolution satellite data, said Fa Li, an Earth system scientist at the University of Texas at Austin and lead author of the study. These data have a relatively low resolution (one pixel from these satellites represents 25 square kilometers) but can pierce through dense foliage, making them invaluable for wetlands research, Li said.

In the new research, Li and his colleagues turned to high-resolution satellite imagery. One pixel from these satellites is 30 square meters, which is just over half the size of an Olympic swimming pool. By combining this imagery with emissions data, the researchers were able to refine methane emissions calculations on a global scale.

Most of the 160 million small wetlands the survey revealed were concentrated in northern latitudes in places like Canada and Siberia.

“It’s really high, but I think this value [of 160 million] is certainly underestimated,” said Li.

Small tropical wetlands in particular tended to punch above their weight class, he added.

Such work will ultimately reveal “what level of atmospheric carbon dioxide and methane removal is needed to keep our planet hospitable.”

“Our results show that tropical small wetlands contribute disproportionately to methane emissions,” Li said. “Although tropical regions account for only 15.1% of global small-wetland area, they contribute 37% of methane emissions from small wetlands.”

Though higher-resolution satellite imagery can capture smaller wetlands, the technology is incapable of piercing through tree canopies. Because of this trade-off, forested swamps and other covered wetlands were excluded from the study.

“Methane emission rates are positively related to the temperature,” said Li. As the global temperature increases, these methane-emitting microbes become more productive. “It’s like a snowball that gets bigger and bigger,” he said. Rising global temperatures likely triggered the increased emissions and will continue to feed the tumbling snowball in the future.

Delwiche is excited about the new work and would like to see it extended to eventually cover forested wetlands. “We need accurate estimates of emissions and trends,” she said. Such work will ultimately reveal “what level of atmospheric carbon dioxide and methane removal is needed to keep our planet hospitable.”

—Taylor Mitchell Brown (@tmitchellbrown.bsky.social), Science Writer

Citation: Brown, T. M. (2026), Big trouble from little wetlands, Eos, 107, https://doi.org/10.1029/2026EO260232. Published on 17 July 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.

SummaryIn a growing number of studies, researchers have presented induced polarization as a dielectric-related phenomenon arising from the complex nature of the permittivity in the constitutive law associated with the displacement current. Using Ampères’s law, they then write the conductivity as a complex number with an imaginary part related to the real part of the permittivity mixing Maxwell-Wagner-Sillars polarization and induced polarization phenomena. This presentation may be misleading to students and new researchers in the field. In terms of underlying physics, induced polarization phenomena have nothing to do with the displacement current density and Maxwell-Wagner-Sillars polarization should not be considered as an induced polarization mechanism. At the microscopic level, low-frequency polarization arises because the ionic fluxes responsible for the local electrical current are coupled not only through the long-range Coulombic effect but also through their physical interactions associated with diffusion phenomena driven by the random thermal motion of charge carriers. The thermodynamic force associated with ionic migration is not the electrical field alone but electrochemical potential gradients (induction effect can be accounted for, if needed, in the electrical field component of the Nernst-Planck equation governing the fate of ions in the pore space and along the surface of the mineral grains in their so-called electrical double layer). This has been known since the seminal papers of D.J. Marshall & T.R Madden in the 50s and Vinegar & Waxman in the 80s. This point seems, however, forgotten in recent studies leading to some misconceptions preventing a mechanistic understanding of the induced polarization processes and broad-band spectroscopic data.

Publication date: 15 July 2026

Source: Advances in Space Research, Volume 78, Issue 2

Author(s): Tristan Camilleri, Manuel Cervera, Bruce Ward, Andrew MacKinnon

Publication date: 15 July 2026

Source: Advances in Space Research, Volume 78, Issue 2

Author(s): Cheng Wang, Yuhan Liu, Yueyong Lyu, Xusheng Xu, Bin Song

Publication date: 15 July 2026

Source: Advances in Space Research, Volume 78, Issue 2

Author(s): Dongsheng Zhao, Yuhao Hou, Kefei Zhang, Hao Liu, Qianxin Wang, Wang Li, Longjiang Li, Zhongchao Shi, Craig M. Hancock, Gethin Wyn Roberts, Andrzej Krankowski, Mardina Abdullah, Guanqing Li, Yiming Quan

Publication date: 15 July 2026

Source: Advances in Space Research, Volume 78, Issue 2

Author(s): R. Chen, J. Yang, Z. Huang