Roger Bryant and David Fike’s research reveals that pyrite sulfur isotopes mainly reflect local conditions, shifting fundamental understanding of oceanic environmental studies.
Credit: Clive Jones, Washington University in St. Louis Roger Bryant studied ocean floor core samples at the Secondary Ion Mass Spectrometry (SIMS) facility at Washington University in St. Louis during his PhD studies. Bryant and David Fike have used this data to prove a discovery that will fundamentally change how scientists use pyrite sulfur isotopes to study oceanic conditions. « Separating out signals recorded at the seafloor
Newswise — Blame it on plate tectonics. The deep ocean is never preserved, but instead is lost to time as the seafloor is subducted. Geologists are mostly left with shallower rocks from closer to the shoreline to inform their studies of Earth history.
Signals from the Sea
“We have only a good record of the deep ocean for the last ~180 million years,” said David Fike, the Glassberg/Greensfelder Distinguished University Professor of Earth, Environmental, and Planetary Sciences in Arts & Sciences at Washington University in St. Louis. “Everything else is just shallow-water deposits. So it’s really important to understand the bias that might be present when we look at shallow-water deposits.”
One of the ways that scientists like Fike use deposits from the seafloor is to reconstruct timelines of past ecological and environmental change. Researchers are keenly interested in how and when oxygen began to build up in the oceans and atmosphere, making Earth more hospitable to life as we know it.
For decades they have relied on pyrite, the iron-sulfide mineral known as “fool’s gold,” as a sensitive recorder of conditions in the marine environment where it is formed. By measuring the bulk isotopic composition of sulfur in pyrite samples — the relative abundance of sulfur atoms with slightly different mass — scientists have tried to better understand ancient microbial activity and interpret global chemical cycles.
But the outlook for pyrite is not so shiny anymore. In a pair of companion papers published Nov. 24 in the journal Science, Fike and his collaborators show that variations in pyrite sulfur isotopes may not represent the global processes that have made them such popular targets of analysis.
Instead, Fike’s research demonstrates that pyritte responds predominantly to local processes that should not be taken as representative of the whole ocean. A new microanalysis approach developed at Washington University helped the researchers to separate out signals in pyrite that reveal the relative influence of microbes and that of local climate.
For the first study, Fike worked with Roger Bryant, who completed his graduate studies at Washington University, to examine the grain-level distribution of pyrite sulfur isotope compositions in a sample of recent glacial-interglacial sediments. They developed and used a cutting-edge analytical technique with the secondary-ion mass spectrometer (SIMS) in Fike’s laboratory.
“We analyzed every individual pyrite crystal that we could find and got isotopic values for each one,” Fike said. By considering the distribution of results from individual grains, rather than the average (or bulk) results, the scientists showed that it is possible to tease apart the role of the physical properties of the depositional environment, like the sedimentation rate and the porosity of the sediments, from the microbial activity in the seabed.
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“We found that even when bulk pyrite sulfur isotopes changed a lot between glacials and interglacials, the minima of our single grain pyrite distributions remained broadly constant,” Bryant said. “This told us that microbial activity did not drive the changes in bulk pyrite sulfur isotopes and refuted one of our major hypotheses.”
“Using this framework, we’re able to go in and look at the separate roles of microbes and sediments in driving the signals,” Fike said. “That to me represents a huge step forward in being able to interpret what is recorded in these signals.”
In the second paper, led by Itay Halevy of the Weizmann Institute of Science and co-authored by Fike and Bryant, the scientists developed and explored a computer model of marine sediments, complete with mathematical representations of the microorganisms that degrade organic matter and turn sulfate into sulfide and the processes that trap that sulfide in pyrite.
“We found that variations in the isotopic composition of pyrite are mostly a function of the depositional environment in which the pyrite formed,” Halevy said. The new model shows that a range of parameters of the sedimentary environment affect the balance between sulfate and sulfide consumption and resupply, and that this balance is the major determinant of the sulfur isotope composition of pyrite.
“The rate of sediment deposition on the seafloor, the proportion of organic matter in that sediment, the proportion of reactive iron particles, the density of packing of the sediment as it settles to the seafloor — all of these properties affect the isotopic composition of pyrite in ways that we can now understand,” he said.
Importantly, none of these properties of the sedimentary environment are strongly linked to the global sulfur cycle, to the oxidation state of the global ocean, or essentially any other property that researchers have traditionally used pyrite sulfur isotopes to reconstruct, the scientists said.
“The really exciting aspect of this new work is that it gives us a predictive model for how we think other pyrite records should behave,” Fike said. “For example, if we can interpret other records — and better understand that they are driven by things like local changes in sedimentation, rather than global parameters about ocean oxygen state or microbial activity — then we can try to use this data to refine our understanding of sea level change in the past.”
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
Did James Webb Find Life on a Distant Planet Recently?
Recent findings from the James Webb Space Telescope suggest potential biosignatures on exoplanet K2-18b, including dimethyl sulfide, indicating possible microbial life, though further research is necessary.
James Webb Space Telescope mission observing universe. This image elements furnished by NASA
While the answer to that question is not a definitive “yes,” recent findings from the James Webb Space Telescope (JWST) are providing what scientists are calling the “strongest evidence yet” of potential life on an exoplanet, specifically K2-18b. This discovery opens a new frontier in our understanding of the universe and the possibility of life beyond Earth.
The Discovery
A dedicated team of astronomers recently utilized the powerful capabilities of the JWST to analyze the atmosphere of K2-18b, a super-Earth exoplanet located an incredible 124 light-years away from our planet. Their findings have revealed chemical signatures in the atmosphere that warrant further investigation.
The Biosignature
Among the intriguing detections was dimethyl sulfide (DMS) and potentially dimethyl disulfide (DMDS). These compounds are significant because, on Earth, they are predominantly produced by living organisms, with marine microbes being the primary source. The presence of these chemicals in K2-18b’s atmosphere suggests the potential for biological processes at work.
The Context
DMS is primarily emitted by marine phytoplankton, a crucial element of oceanic ecosystems. The detection of DMS in the atmosphere of K2-18b is interpreted as a potential indicator of microbial life, potentially thriving in an ocean on the planet. This tantalizing prospect encourages scientists to contemplate the types of ecosystems that could flourish far beyond Earth.
Caution
However, it is essential to approach these findings with the appropriate level of caution. While the presence of these compounds is compelling, scientists emphasize that this does not serve as definitive confirmation of life. Further observations and rigorous analyses are necessary to rule out other non-biological explanations for the presence of DMS and DMDS in K2-18b’s atmosphere.
Significance
This detection represents a significant leap forward in the ongoing quest to uncover extraterrestrial life. It is the first time scientists have successfully identified potential biosignatures on an exoplanet using advanced astronomical technology. This marks a pivotal moment in astrobiology, helping to narrow the focus of future exploration.
Future Research
The JWST will continue to play a vital role in studying K2-18b, as well as other exoplanets, in the relentless pursuit of knowledge about life in the cosmos. Ongoing research will seek to deepen our understanding and potentially corroborate these exciting initial findings.
In conclusion, while the James Webb Space Telescope has not definitively found life on K2-18b, the detection of biosignatures in its atmosphere represents a groundbreaking step in humanity’s exploration of worlds beyond our own. As scientists push forward, we stand on the brink of potentially transformative discoveries that could change our understanding of life in the universe. Stay tuned for further updates as we journey into the stars!
The science section of our news blog, STM Daily News, provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
One of two main craters on Alaska’s Mount Spurr, shown in 1991. Earthquake activity suggests the volcano is close to erupting again in 2025.
R.G. McGimsey/Alaska Volcano Observatory/U.S. Geological Survey, CC BYDavid Kitchen, University of Richmond
Volcanoes inspire awe with spectacular eruptions and incandescent rivers of lava, but often their deadliest hazard is what quietly falls from the sky.
When a large volcano erupts, as Mount Spurr appears close to doing about 80 miles from Anchorage, Alaska, it can release enormous volumes of ash. Fine ash can infiltrate the lungs of people and animals who breathe it in, poison crops and disrupt aquatic life. Thick deposits of ash can collapse roofs, cripple utilities and disrupt transport networks.
Ash may lack the visual impact of flowing lava, but as a geologist who studies disasters, I’m aware that ash travels farther, lasts longer and leaves deep scars.
Ash buried cars and buildings after the 1984 eruption of Rabaul in Papua New Guinea.Volcano Hazards Program, U.S. Geological Survey
Volcanic ash: What it is, and why it matters
Volcanic ash forms when viscous magma – molten rock from deep beneath Earth’s surface – erupts, exploding into shards of rock, mineral and glass carried in a near-supersonic stream of hot gas.
Towering clouds of ash rise several miles into the atmosphere, where the ash is captured by high-altitude winds that can carry it hundreds or even thousands of miles.
As the volcanic ash settles back to Earth, it accumulates in layers that typically decrease in thickness with distance from the eruption source. Near the vent, the ash may be several feet deep, but communities farther away may see only a dusting.
When Mount Spurr erupted in 1992, a dark column of ash and gas shot into the atmosphere from the volcano’s Crater Peak vent. Wind patterns determine where the ash will fall.U.S. Geological Survey
Breathing danger: Health risks from ash
Breathing volcanic ash can irritate the throat and lungs, trigger asthma attacks and aggravate chronic respiratory conditions such as COPD.
The finest particles pose the greatest risk because they can penetrate deep into the lungs and cause death by asphyxiation in the worst cases. Mild, short-term symptoms often resolve with rest. However, the long-term consequences of ash exposure can include silicosis, a lung disease and a possible cause of cancer.
The danger increases in dry regions where fallen ash can be kicked up into the air again by wind or human activity.
Risks to pets and livestock
Humans aren’t the only ones at risk. Animals experience similar respiratory symptoms to humans.
Domestic pets can develop respiratory distress, eye inflammation and paw irritation from exposure to ash.
Ash covers sheep in Argentina after the 2011 Puyehue volcanic eruption in Chile.Federico Grosso/U.S. Geological Survey
Livestock face greater dangers. If grazing animals eat volcanic ash, it can damage their teeth, block their intestines and poison them.
During the 2010 Eyjafjallajökull eruption in Iceland, farmers were advised to shelter sheep and cattle because the ash contained fluoride concentrations above the recognized safety threshold of 400 parts per million. Animals that remained exposed became sick and some died.
Harm to crops, soil and water
Soil and crops can also be damaged. Volcanic ash alters the acidity of soil and introduces harmful elements such as arsenic and sulfur into the environment.
While the ash can add nutrients such as potassium and phosphorus that enhance fertility, the immediate impact is mostly harmful.
Ash can smother crops, block sunlight and clog the tiny stomata, or pores, in leaves that allow plants to exchange gases with the atmosphere. It can also introduce toxins that render food unmarketable. Vegetables, fruit trees and vines are particularly vulnerable, but even sturdy cereals and grasses can die if ash remains on leaves or poisons emerging shoots.
Following the 1991 Mount Pinatubo eruption, vast tracts of farmland in central Luzon in the Philippines were rendered unproductive for years due to acidic ash and buried topsoil. If multiple ashfalls occur in a growing season, crop failure becomes a near certainty. It was the cause of a historic famine that followed the eruption of Mount Tambora in 1815.
Ash from a 1953 eruption of Mount Spurr included very fine grains, like powder. The ash cloud reached about 70,000 feet high and left Anchorage under a blanket of ash up to a quarter-inch deep, according to a U.S. Geological Survey report at the time.James St. John via Wikimedia Commons, CC BYElectron microscope images of ash show how sharp the shards are. The top left image of shards from Mount Etna in 2002 is 1 mm across. Top right is an ash particle from Mount St. Helens magnified 200 times. The shards in the lower images are less than 0.064 mm.Volcano Hazards Program, U.S. Geological Survey
Ash can also contaminate surface water by introducing toxins and increasing the water’s acidity. The toxins can leach into groundwater, contaminating wells. Fine ash particles can also settle in waterways and smother aquatic plants and animals. During the 2008 Chaitén eruption in Chile, ash contamination led to widespread fish deaths in the Río Blanco.
Ash can ground airplanes, gum up infrastructure
Ash clouds are extremely dangerous to aircraft. The glassy ash particles melt when sucked into jet turbines, clog fuel systems and can stall engines in midair.
In 1982, British Airways Flight 9 lost power in all four engines after flying through an ash cloud. A similar incident occurred in 1989 to KLM Flight 867 over Alaska. In 2010, Iceland’s Eyjafjallajökull eruption grounded more than 100,000 flights across Europe, disrupting travel for over 10 million passengers and costing the global economy billions of dollars.
Volcanic ash can also wreak havoc on infrastructure by clogging water supplies, short-circuiting electrical systems and collapsing roofs under its weight. It can disrupt transportation, communication, rescue and power networks, as the 1991 eruption of Mount Pinatubo in the Philippines dramatically demonstrated.
What to do during ashfall
During an ashfall event, the most effective strategy to stay safe is to stay indoors as much as possible and avoid inhaling ash particles.
Anyone who must go outside should wear a properly fitted N95 or P2 mask. Cloth masks provide little protection against fine ash. Rainwater tanks, troughs and open wells should be covered and monitored for contamination. Livestock should be moved to clean pastures or given uncontaminated fodder.
The challenges Alaska is facing if Mount Spurr erupts.
To reduce structural damage, ash should be cleared from roofs and gutters promptly, especially before rainfall.
Older adults, children and people who are sick are at greatest risk, particularly those living in poorly ventilated homes. Rural communities that are dependent on agriculture and livestock are disproportionately affected by ashfall, as are low-income people who lack access to clean water, protective masks or safe shelter.
Communities can stay informed about ash risks through official alerts, including those from the Volcanic Ash Advisory Centers, which monitor ash dispersion and issue timely warnings. The International Volcanic Health Hazard Network also offers guidelines on personal protection, emergency planning and ash cleanup.
The long tail of ash
Volcanic ash may fall quietly, but its effects are widespread, persistent and potentially deadly. It poses a chronic threat to health, agriculture, infrastructure and aquatic systems.
Recognizing the risk is a crucial first step to protecting lives. Effective planning and public awareness can further help reduce the damage.
David Kitchen, Associate Professor of Geology, University of Richmond
This article is republished from The Conversation under a Creative Commons license. Read the original article.
In a groundbreaking achievement for space tourism, Blue Origin successfully completed its 31st mission with the New Shepard rocket, marking a significant milestone in human spaceflight. This latest journey not only added another chapter to the annals of space exploration but also carried an inspiring and trailblazing crew that is sure to leave a lasting impact on humanity’s journey to the stars.
A Stellar Crew of Trailblazers
On this momentous flight, Blue Origin had the honor of launching an extraordinary crew comprised entirely of trailblazing women: Aisha Bowe, Amanda Nguyễn, Gayle King, Katy Perry, Kerianne Flynn, and Lauren Sánchez. Each of these remarkable individuals brings a wealth of experience and influence, and together, they ventured beyond the confines of our planet, reaching heights that had once only been dreams for many.
Phil Joyce, Senior Vice President of New Shepard, expressed profound admiration for the crew, stating, “What a privilege to witness this crew of trailblazers depart the capsule today. Each of these women is a storyteller who will use their voices—individually and together—to channel their life-changing experience today into creating lasting impact that will inspire people across our planet for generations.” It’s clear that this mission was more than just a flight; it was a symbol of hope and inspiration for future generations of explorers and dreamers.
A Milestone for New Shepard
With this successful mission, New Shepard has now flown 58 people to the edge of space, with four individuals having embarked on this extraordinary journey twice. The rocket’s reliability and safety continue to bolster confidence in commercial space travel, encouraging a new wave of adventurers eager to experience the thrill of weightlessness and the breathtaking views of Earth from above.
In addition to exhilarating experiences, Blue Origin’s missions contribute to the growing narrative of inclusivity and diversity in space exploration. By prioritizing representation within its astronaut crews, Blue Origin is actively reshaping how we view space travel, fostering a community that is open to all.
Join the Adventure
If you missed this awe-inspiring flight, don’t worry! You can watch the full replay of the mission below and relive the magic of this transformative journey. Additionally, those looking to be a part of future missions can sign up to fly on an upcoming New Shepard adventure. The chance to soar into the cosmos awaits you!
For space enthusiasts and supporters, commemorative merchandise from this mission is available for purchase at the Blue Origin Shop. Celebrate this historic achievement and bring a piece of the cosmos into your life.
Looking Ahead
As we continue to push boundaries and explore the mysteries of outer space, missions like these remind us of the potential that lies within each of us. Blue Origin’s commitment to expanding access to space is not just about reaching new heights; it’s about empowering individuals to share their stories, inspire change, and dream bigger than ever before. The future of space exploration is bright, and we can’t wait to see where this new era takes us!
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So gear up, dreamers, adventurers, and future astronauts—the stars are closer than ever!
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
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