Scientists crack the explosive secret of how diamonds reach the surface

 If you've ever held or beheld a diamond, there's a good chance it came from a kimberlite. Over 70% of the world's diamonds are mined from these unique volcanic structures. Yet despite decades of study, scientists are still working to understand how exactly kimberlites erupt from deep in Earth's mantle to the surface.

Kimberlites -- carrot-shaped volcanic pipes that erupt from mantle depths greater than 150 km -- have long fascinated geologists as windows into the deep Earth. Their mantle-derived melt ascends rapidly through the mantle and crust, with some estimates suggesting ascent rates of up to 80 miles per hour before kimberlites erupt violently at the surface. Along the way, the magma captures xenoliths and xenocrysts, fragments of the rocks encountered on its path.

"They're very interesting and still very enigmatic rocks," despite being well-studied, says Ana Anzulović, a doctoral research fellow at the University of Oslo's Centre for Planetary Habitability.

In a study published this month in the journal Geology, Anzulović and colleagues from the University of Oslo have taken a major step toward solving the puzzle. By modelling how volatile compounds like carbon dioxide and water influence the buoyancy of proto-kimberlite melt relative to surrounding materials, they quantified for the first time what it takes to erupt a kimberlite.

Diamonds make it to the surface in kimberlites because their rapid ascent prevents them from reverting to graphite, which is more stable at shallow pressures and temperatures. But the composition of the kimberlite's original melt -- and how it rises so fast -- has remained mysterious.

"They start off as something that we cannot measure directly," says Anzulović. "So we don't know what a proto-kimberlite, or parental, melt would be like. We know approximately but everything we know basically comes from the very altered rocks that get emplaced."

To constrain the composition of these parental melts, the team focused on the Jericho kimberlite, which erupted into the Slave craton of far northwest Canada. Using chemical modelling, they tested different original mixtures of carbon dioxide and water.

"Our idea was, well, let's try to create a chemical model of a kimberlite, then vary CO2 and H2O," says Anzulović. "Think of it as trying to sample a kimberlite as it ascends at different pressure and temperature points."

The researchers used molecular dynamics software to simulate atomic forces and track how atoms in a kimberlite melt move under varying depths. From these calculations, they determined the density of the melt at different conditions and whether it remained buoyant enough to rise.

"The most important takeaway from this study is that we managed to constrain the amount of CO2 that you need in the Jericho kimberlite to successfully ascend through the Slave craton," Anzulović says. "Our most volatile-rich composition can carry up to 44% of mantle peridotite, for example, to the surface, which is really an impressive number for such a low viscosity melt."

The study also shows how volatiles play distinct roles. Water increases diffusivity, keeping the melt fluid and mobile. Carbon dioxide helps structure the melt at high pressures but, near the surface, it degasses and drives the eruption upward. For the first time, researchers demonstrated that the Jericho kimberlite needs at least 8.2% CO2 to erupt; without it, diamonds would remain locked in the mantle.

"I was actually pretty surprised that I can take such a small scale system and actually observe, 'Okay, if I don't put any carbon in, this melt will be denser than the craton, so this will not erupt,'" says Anzulović. "It's great that modeling kimberlite chemistry can have implications for such a large-scale process."

Source: ScienceDaily

Tiny stones rewrite Earth’s evolution story

 Earth scientists often face huge challenges when researching the Earth's history: many significant events occurred such a long time ago that there is little direct evidence available. Consequently, researchers often have to rely on indirect clues or on computer models. The team led by ETH Professor Jordon Hemingway, however, has now discovered a unique natural witness to this period: tiny egg-shaped iron oxide stones that can be used to directly measure the carbon reserves in the primordial ocean.

Viewed on the outside, they resemble grains of sand, but in terms of their formation, these so-called ooids are more like rolling snowballs: they grow by layers as they are pushed across the sea floor by the waves. In the process, organic carbon molecules adhere to them and become part of the crystal structure.Examining these impurities, Hemingway's team has succeeded in retracing the supply of organic carbon in the sea -- by up to 1.65 billion years. In the journal Nature, the researchers show that, between 1,000 and 541 million years ago, this store was considerably lower than previously assumed. These findings refute the common explanations of significant geochemical and biological events of that time and cast a new light on the history of the Earth.

The ocean as a reservoir of life's building blocks

How does carbon get into the oceans? On the one hand, carbon dioxide (CO2) dissolves from the air into seawater and is transported to the depths by mixing processes and ocean currents, where it is retained for a long time. On the other hand, organic carbon is produced by photosynthetic organisms such as phytoplankton or certain bacteria. Using the energy of sunlight and CO2, these microscopic organisms produce organic carbon compounds themselves. When the organisms die, they slowly sink towards the sea floor as marine snow. If it reaches the sea floor without being eaten by organisms along the way, the carbon is stored in the sea floor for millions of years.

But it is not only phytoplankton that provides a supply of carbon components. The building blocks of life are also reused: microorganisms decompose excrement and dead organisms, thereby releasing the building blocks again. These molecules form what is known as dissolved organic carbon, which drifts freely in the ocean: a huge reservoir of building blocks that contains 200 times more carbon than is actually 'built into' marine life.

The oxygen revolution changed everything

Based on anomalies in oceanic sedimentary rocks, researchers assumed that this building block reservoir must have been particularly voluminous between 1,000 and 541 million years ago. For a long time, this assumption served as the foundation for explaining how ice ages and complex life emerged at the same time. The photosynthetic production of the building blocks of life is closely linked to the development of the atmosphere and more complex life forms. It was only through photosynthesis that oxygen began to accumulate in the atmosphere.In two waves -- referred to as the oxygen catastrophes -- the oxygen content rose to its current level of 21 percent. Both events were accompanied by extreme ice ages that covered the entire planet in glaciers. Nevertheless, life continued to tinker and potter with new inventions: during the first oxygen catastrophe 2.4 to 2.1 billion years ago, organisms developed a metabolism converting food into energy with the help of oxygen. This exceedingly efficient way of generating energy enabled the development of more complex life forms.

Carbon content much lower than assumed

Hemingway's team is tracking such connections between geochemical and biological developments. The researchers have developed a new method that allows them to directly determine the size of the marine building block store at that particular time, based on the carbon particles in ooids.

"Our results contradict all previous assumptions," as Hemingway summarizes. According to the measurements taken by the ETH researchers, between 1,000 to 541 million years ago, the ocean did not contain more, but actually 90 to 99 percent less dissolved organic carbon than it does today. It was only after the second oxygen catastrophe that the values rose to the current level of 660 billion tonnes of carbon.

"We need new explanations for how ice ages, complex life and oxygen increase are related," says lead author Nir Galili. He explains the massive shrinkage of the carbon store with the emergence of larger organisms at that time: single-celled and early multicellular organisms sank faster after their death, thereby increasing marine snowfall.

However, the carbon particles were not recycled in the deeper layers of the ocean because there was very little oxygen there. They settled on the sea floor, causing the reservoir of dissolved organic carbon to decline sharply. It was only when oxygen accumulated in the deep sea that the carbon reservoir grew back to its current volume.

From the primordial ocean to the present day

Although the periods studied are long past, the research findings are significant for the future. They change our view of how life on earth and possibly also on exoplanets has developed. At the same time, they help us understand how the Earth responds to disturbances, and humans are one such disturbance: the warming and pollution of the oceans caused by human activities are currently leading to a decline in marine oxygen levels. Consequently, it cannot be ruled out that the events described could repeat themselves in the distant future.

Source: ScienceDaily

The billion-year reign of fungi that predated plants and made Earth livable

 New research published in Nature Ecology & Evolution sheds light on the timelines and pathways of evolution of fungi, finding evidence of their influence on ancient terrestrial ecosystems. The study, led by researchers from the Okinawa Institute of Science and Technology (OIST) and collaborators, indicates the diversification of fungi hundreds of millions of years before the emergence of land plants.

The five paths to a complex world

Professor Gergely J. Szöllősi, author on this study and head of the Model-Based Evolutionary Genomics Unit at OIST explains the foundations of this research. "Complex multicellular life -- organisms made of many cooperating cells with specialized jobs -- evolved independently in five major groups: animals, land plants, fungi, red algae, and brown algae. On a planet once dominated by single-celled organisms, a revolutionary change occurred not once, but at least five separate times: the evolution of complex multicellular life. Understanding when these groups emerged is fundamental to piecing together the history of life on Earth."

Emergence here was not simply a matter of cells clumping together; it was the dawn of organisms, where cells took on specialized jobs and were organized into distinct tissues and organs, much like in our own bodies. This evolutionary leap required sophisticated new tools, including highly developed mechanisms for cells to adhere to one another and intricate systems for them to communicate across the organism, and arose independently in each of the five major groups.

The difficulties of dating evolutionary divergence

For most of these groups, the fossil record acts as a geological calendar, providing anchor points in deep time. For example, red algae show up possibly as early as about 1.6 billion years ago (in candidate seaweed-like fossils from India); animals appear by around 600 million years ago (Ediacaran fossils such as the quilted pancake like Dickinsonia); land plants take root roughly 470 million years ago (tiny fossil spores); and brown algae (kelp-like forms) diversified tens to hundreds of millions of years later still. Based on this evidence, a chronological picture of life's complexity emerges.

There is, however, a notable exception to this fossil-based timeline: fungi. The fungal kingdom has long been an enigma for paleontologists. Their typically soft, filamentous bodies mean they rarely fossilize well. Furthermore, unlike animals or plants, which appear to have a single origin of complex multicellularity, fungi evolved this trait multiple times from diverse unicellular ancestors, making it difficult to pinpoint a single origin event in the sparse fossil record.

Reading the genetic clock

To overcome the gaps in the fungal fossil record, scientists use a "molecular clock." The concept is that genetic mutations accumulate in an organism's DNA at a relatively steady rate over generations, like the ticking of a clock. By comparing the number of genetic differences between two species, researchers can estimate how long ago they diverged from a common ancestor.

However, a molecular clock is uncalibrated; it can reveal relative time but not absolute years. To set the clock, scientists need to calibrate it with "anchor points" from the fossil record. Given the scarcity of fungal fossils, this has always been a major challenge. The OIST-led team addressed this by incorporating a novel source of information: rare gene "swaps" between different fungal lineages, a process known as horizontal gene transfer (HGT).

Prof. Szöllősi explains this concept. "While genes are normally passed down "vertically" from parent to child, HGT is like a gene jumping "sideways" from one species to another. These events provide powerful temporal clues," he says. "If a gene from lineage A is found to have jumped into lineage B, it establishes a clear rule: the ancestors of lineage A must be older than the descendants of lineage B."

By identifying 17 such transfers, the team established a series of "older than/younger than" relationships that, alongside fossil records, helped to tighten and constrain the fungal timeline.

A new history for an ancient kingdom

The analysis suggests a common ancestor of living fungi dating to roughly 1.4-0.9 billion years ago -- well before land plants. That timing supports a long prelude of fungi-algae interactions that helped set the stage for life on land.

Co-first author on this study, Dr. Lénárd L. Szánthó, emphasizes the importance of these findings. "Fungi run ecosystems -- recycling nutrients, partnering with other organisms, and sometimes causing disease. Pinning down their timeline shows fungi were diversifying long before plants, consistent with early partnerships with algae that likely helped pave the way for terrestrial ecosystems."

This revised timeline fundamentally reframes the story of life's colonization of land. It suggests that for hundreds of millions of years before the first true plants took root, fungi were already present, likely interacting with algae in microbial communities. This long, preparatory phase may have been essential for making Earth's continents habitable. By breaking down rock and cycling nutrients, these ancient fungi could have been the first true ecosystem engineers, creating the first primitive soils and fundamentally altering the terrestrial environment. In this new view, plants did not colonize a barren wasteland, but rather a world that had been prepared for them over eons by the ancient and persistent activity of the fungal kingdom.

Source:ScienceDaily

From gentle giants to ghostly hunters, sharks face an unseen peril

 The habitat of thirty species of sharks, rays, and chimaeras, also called ghost sharks, overlap with areas where proposed deep-sea mining may occur, according to new research published in Current Biology and led by University of Hawai'i at Mānoa oceanographers. Nearly two-thirds of these species are already threatened with extinction due to human impacts, so deep-sea mining, which will disrupt the seafloor and discharge large plumes of sediment into the water above, has the potential to elevate their extinction risk.

"Deep-sea mining is a new potential threat to this group of animals which are both vital in the ocean ecosystem and to human culture and identity," said Aaron Judah, lead author of the study and oceanography graduate student in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST). "By identifying and calling attention to this threat and recommending potential conservation pathways, I hope we will be better positioned to support healthy shark, ray, and chimaera populations into the future."

Where there is overlap, there is risk

Judah collaborated with an international team of experts to overlay the global maps of species ranges created by the IUCN Shark Specialist Group with contract areas and reserved areas allocated for deep-sea mining by the International Seabed Authority. The researchers also accounted for how each species reproduces and how deep they dive in order to estimate their vulnerability to mining impacts. For example, species such as skates and chimaeras lay eggs on the seafloor and therefore mining vehicles could pose a threat to nurseries.

The species they assessed included iconic examples such as the whale shark, manta rays, and the megamouth shark, and also many lesser known, but just as interesting deep-sea species, such as the pygmy shark, chocolate skate, and point-nosed chimaera, which comes from a unique group of cartilaginous fishes similar to sharks and rays, sometimes called ghost sharks.

The team discovered that 30 species could be impacted by discharge plumes and 25 of the 30 species could also be impacted by seafloor disruptions associated with mining. They also found that because many of the species inhabit a variety of habitats along the depth range or are deep divers, mining impacts may overlap more than half of the depth range of 17 species.

Assessing risk to minimize impacts

Deep-sea mining is set to potentially occur in the Clarion-Clipperton Zone, which is a large abyssal plain area that spans from the waters around Hawai'i into the eastern Pacific Ocean. To make the best management decisions, the potential impacts on marine life and the communities that depend on them must be known.

"Sharks and their relatives are the second most threatened vertebrate group on the planet, mostly from overfishing," said Jeff Drazen, study senior author and professor of Oceanography at SOEST. "Because of their vulnerability, they should be considered in ongoing discussions of the environmental risks from deep-sea mining, and those responsible for monitoring their health should be aware that mining could pose an additional risk."The authors offer a number of recommendations to improve conservation of these species under the footprint of mining, such as establishing monitoring programs, including them in environmental impact assessments, and creating protected areas. These recommendations could be adopted by the International Seabed Authority in their regulations for creating environmental impact assessments, or by contractors in executing scientific baseline assessments."Many of the shark species identified in the analysis are highly mobile and can move across wide swaths of ocean," said Judah. "Given their mobility and the proximity of Hawai'i to the areas allocated for mining, impacts in these areas may stretch indirectly to ecosystems near the island chain."Judah continues to research and report species range extensions for animals not included in the initial assessment, which may add additional species to this group of animals at risk from mining impacts.

Source: ScienceDaily

Scientists just recreated a wildfire that made its own weather

 On September 5, 2020, California's Creek Fire grew so severe that it began producing it's own weather system. The fire's extreme heat produced an explosive thunderhead that spewed lightning strikes and further fanned the roaring flames, making containment elusive and endangering the lives of firefighters on the ground. These wildfire-born storms have become a growing part of fire seasons across the West, with lasting impacts on air quality, weather, and climate. Until now, scientists have struggled to replicate them in Earth system models, hindering our ability to predict their occurrence and understand their impacts on the global climate. Now, a new study provides a breakthrough by developing a novel wildfire-Earth system modeling framework.

The research, published September 25th in Geophysical Research Letters, represents the first successful simulation of these wildfire-induced storms, known as pyrocumulonimbus clouds, within an Earth system model. Led by DRI scientist Ziming Ke, the study successfully reproduced the observed timing, height, and strength of the Creek Fire's thunderhead - one of the largest known pyrocumulonimbus clouds seen in the U.S., according to NASA. The model also replicated multiple thunderstorms produced by the 2021 Dixie Fire, which occurred under very different conditions. Accounting for the way that cloud development is aided by moisture lofted into the higher reaches of the atmosphere by terrain and winds is key to their findings.

"This work is a first-of-its-kind breakthrough in Earth system modeling," Ke said. "It not only demonstrates how extreme wildfire events can be studied within Earth system models, but also establishes DRI's growing capability in Earth system model development -- a core strength that positions the institute to lead future advances in wildfire-climate science."

When a pyrocumulonimbus cloud forms, it injects smoke and moisture into the upper atmosphere at magnitudes comparable to those of small volcanic eruptions, impacting the way Earth's atmosphere receives and reflects sunlight. These fire aerosols can persist for months or longer, altering stratospheric composition. When transported to polar regions, they affect Antarctic ozone dynamics, modify clouds and albedo, and accelerate ice and snow melt, reshaping polar climate feedbacks. Scientists estimate that tens to hundreds of these storms occur globally each year, and that the trend of increasingly severe wildfires will only grow their numbers. Until now, failing to incorporate these storms into Earth system models has hindered our ability to understand this natural disturbance's impact on global climate.

The research team also included scientists from Lawrence Livermore National Laboratory, U.C. Irvine, and Pacific Northwest National Laboratory. Their breakthrough leveraged the Department of Energy's (DOE) Energy Exascale Earth System Model (E3SM) to successfully capture the complex interplay between wildfires and the atmosphere.

"Our team developed a novel wildfire-Earth system modeling framework that integrates high-resolution wildfire emissions, a one-dimensional plume-rise model, and fire-induced water vapor transport into DOE's cutting-edge Earth system model," Ke said. "This breakthrough advances high-resolution modeling of extreme hazards to improve national resilience and preparedness, and provides the framework for future exploration of these storms at regional and global scales within Earth system models."

Source: ScienceDaily

1,000 Swiss glaciers already gone, and the melting is speeding up

 Even the United Nations International Year of Glaciers' Preservation has seen further massive melting of glaciers in Switzerland. A winter with little snow was followed by heat waves in June 2025 that saw glaciers nearing the record levels of losses of 2022. Snow reserves from the winter were already depleted in the first half of July, and the ice masses began to melt earlier than had rarely ever been recorded. The cool weather in July provided some relief and prevented an even worse outcome. Nevertheless, almost a further three per cent of the ice volume was lost across Switzerland this year, and this is the fourth greatest shrinkage after the years 2022, 2023 and 2003. 2025 therefore importantly contributed to the decade with the most rapid ice loss. Glaciers all over Switzerland have lost a quarter of their volume since 2015. Over 1,000 small glaciers have already disappeared.

In particular, glaciers from the winter disappeared there up to the summit level. As a consequence, the ice thickness on, for example, the Claridenfirn (Canton of Glarus), the Plaine Morte Glacier (Canton of Bern) and the Silvretta Glacier (Canton of the Grisons) reduced by over two meters. For glaciers in the southern Canton of Valais, such as the Allalin Glacier or Findel Glacier, the loss was less at around one meter.

Too little snow in winter

In the winter of 2024/2025, the combination of less precipitation and the third warmest six months of winter (October to March) since measurements began led to very low snow depths. For example, less fresh snow fell in parts of the northern and central Grisons than ever before. For this reason, around 13 per cent less snow was evident on the glaciers at the end of April when compared to the period from 2010 to 2020. The second warmest June since records began led to rapid melting of snow right up to the highest altitudes. Following a somewhat cool and damp July, August brought a heatwave with a high zero-degree line recorded in part at over 5,000 metres. In combination, this weather led to above-average temperatures in the summer. Between July and September, a few cold fronts resulted to individual days with fresh snow over 2,500 m above sea level, but this only remained for longer periods in high mountains.

"The continuous diminishing of glaciers also contributes to the destabilizing of mountains," says Matthias Huss, Director of GLAMOS. "This can lead to events such as in the Lötschental valley where an avalanche of rock and ice buried the village of Blatten."

The Swiss Commission for Cryosphere observation (SCC) of the Swiss Academy of Sciences (SCNAT) documents changes in the Alpine cryosphere. It coordinates the long-term Swiss monitoring networks created for snow, glaciers (GLAMOS) and permafrost (PERMOS). The Swiss Commission for Cryosphere observation (SCC) therefore represents those institutions that look after national monitoring networks, such as the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, the Institute for Snow and Avalanche Research SLF, the Swiss Federal Office for Meteorology and Climatology (MeteoSchweiz), the Swiss Federal Institute of Technology in Zurich (ETH Zurich), the Universities of Zurich, Fribourg and Lausanne and the University of Applied Sciences and Arts of Southern Switzerland (SUPSI), or who contribute financially to long-term safeguarding, such as the Swiss Federal Office for the Environment (FOEN), the Swiss Federal Office for Meteorology and Climatology (MeteoSwiss), in the context of the Swiss Global Climate Observing System (GCOS), the Swiss Academy of Sciences (SCNAT) and the Swiss Federal Office of Topography (swisstopo).

Source: ScienceDaily

Japan’s hot springs hold clues to the origins of life on Earth

 Earth was not always the blue-green world we know today: the early Earth's oxygen levels were about a million times lower than we now experience. There were no forests and no animals. For ancient organisms, oxygen was toxic. What did life look like at that time then? A recent study led by Fatima Li-Hau (graduate student at ELSI at the time of the research) along with the supervisor Associate Professor Shawn McGlynn (at the time of research) of the Earth-Life Science Institute (ELSI) at Institute of Science Tokyo, Japan, explores this question by examining iron-rich hot springs that mimic the chemistry of Earth's ancient oceans around the time of one of Earth's most dramatic changes: the oxygenation of the atmosphere. Their findings suggest that early microbial communities used iron along with oxygen released by photosynthetic microbes, for energy, revealing a transitional ecosystem where life turned a waste product of one organism into a new energy source before photosynthesis became dominant.

The Great Oxygenation Event (GOE) occurred around 2.3 billion years ago and marked the rise of atmospheric oxygen, likely triggered by green Cyanobacteria that used sunlight to split water, subsequently converting carbon dioxide into oxygen through photosynthesis. The result is that the current atmosphere is around 78% nitrogen and 21% oxygen, with only traces of other gases such as methane and carbon dioxide, which might have played a greater role before the rise of oxygen. The GOE fundamentally changed the course of life on Earth. This high amount of oxygen allows us animals to breathe, but it also complicates life for ancient life forms, which were almost unaware of the O2 molecule. Understanding how these ancient microbes adapted to the presence of oxygen remains a major question.To answer this, the team studied five hot springs in Japan, which are rich in varied water chemistries. Those five springs (one in Tokyo, two each in Akita and Aomori prefectures) are naturally rich in ferrous iron (Fe2+). They are rare in today's oxygen-rich world because ferrous iron quickly reacts with oxygen and turns into an insoluble ferric iron form (Fe3+). But in these springs, the water still contains high levels of ferrous iron, low levels of oxygen, and a near-neutral pH, conditions thought to resemble parts of the early Earth's oceans.

"These iron-rich hot springs provide a unique natural laboratory to study microbial metabolism under early Earth-like conditions during the late Archean to early Proterozoic transition, marked by the Great Oxidation Event. They help us understand how primitive microbial ecosystems may have been structured before the rise of plants, animals, or significant atmospheric oxygen," says Shawn McGlynn, who supervised Li-Hau during her dissertation work.

In four of the five hot springs, the team found microaerophilic iron-oxidising bacteria to be the dominant microbes. These organisms thrive in low-oxygen conditions and use ferrous iron as an energy source, converting it into ferric iron. Cyanobacteria, known for producing oxygen through photosynthesis, were also present but in relatively small numbers. The only exception was one of the Akita hot springs, where non-iron-based metabolisms were surprisingly dominant.

Using metagenomic analysis, the team assembled over 200 high-quality microbial genomes and used them to analyse in detail the functions of microbes in the community. The same microbes that coupled iron and oxygen metabolism converted a toxic compound into an energy source and helped maintain conditions that allowed oxygen-sensitive anaerobes to persist. These communities carried out essential biological processes such as carbon and nitrogen cycling, and the researchers also found evidence of a partial sulfur cycle, identifying genes involved in sulfide oxidation and sulfate assimilation. Given that hot springs contained very little sulfur compounds, this was a surprising discovery. The researchers propose that this may indicate a "cryptic" sulfur cycle, where microbes recycle sulfur in complex ways that are not yet fully understood.

Source: ScienceDaily