Science

Separating out signals recorded at the seafloor

Roger Bryant and David Fike’s research reveals that pyrite sulfur isotopes mainly reflect local conditions, shifting fundamental understanding of oceanic environmental studies.

Published

2 months ago

November 1, 2024

Daily News Staff

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.

“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.”

Source: Washington University in St. Louis

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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Mysterious Lights Over Oregon: Pilots Report Unusual Aerial Phenomena

Published

2 days ago

December 19, 2024

Rod Washington

This past weekend, the skies of Oregon became the backdrop for an extraordinary event that has both puzzled and dazzled observers. At least four commercial pilots reported encountering unexplained bright lights displaying incredible speeds and erratic movements, renewing interest and debate about aerial phenomena.

The Encounter Details

The first report came from a pilot operating an air ambulance who described a startling experience. A bright, red light zoomed towards his Life Flight plane, only to reverse direction and head back towards the Pacific Ocean at bewildering speeds. The event left the pilot and his crew astounded by the light’s velocity and abrupt maneuvers.

Meanwhile, the pilot of a United Airlines flight over Eugene also reported seeing multiple mysterious objects. These unidentified lights moved vertically and horizontally in patterns that defied easy explanation, with no evidence of military activity in the area at the time.

Adding to the intrigue, the Life Flight pilot noted that one of the lights engaged in a corkscrew pattern, an observation that was corroborated by the aircraft’s collision avoidance system. Air traffic control, maintaining a cautious approach, authorized the pilot to maneuver as necessary to maintain safety.

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Visual Evidence and Continued Sightings

Throughout these encounters, several pilots managed to capture brief video clips. These clips, although hard to discern due to the dark conditions, show glimpses of the unusual red, circular lights. Another report from two Horizon Airlines pilots further confirmed that whatever was out there wasn’t isolated to a single incident or observer.

Experts Weigh In: Possible Explanations

In the wake of these mystifying sightings, experts have been quick to offer explanations. Douglas Buettner, a scientist who has researched similar incidents, suggests that these lights could likely be flares from Starlink satellites. Starlink, a constellation designed by SpaceX to provide global broadband coverage, has been known to produce vivid optical flares when its panels reflect sunlight.

Buettner’s research, which includes previous pilot reports and observations, supports the idea that this natural reflection of sunlight could explain the phenomena observed. However, he also admits the current data is insufficient to conclusively rule out other possibilities.

Government and Public Response

Following these reports, the Federal Aviation Administration (FAA) confirmed the sighting of unidentified lights by a pilot, although they have not commented further. In a recent Senate hearing, the Pentagon’s director overseeing unidentified anomalous phenomena indicated a spike in such reports since the launch of satellite constellations like Starlink, underscoring the growing interest and concern regarding these observations.

The Broader Implications

While the most likely explanation for these mysterious lights points to satellite flares, the repeated occurrences of such phenomena continue to stir the public’s imagination and scientific curiosity. As we advance in our technological capabilities, the skies above us grow increasingly populated with human-made objects that can sometimes return to us as bewildering spectacles.

In either case, these events serve as a reminder of the vast and unexplored frontiers above us and the ever-present human quest for understanding the mysteries of our universe. Whether they turn out to be mundane or truly otherworldly, the skies over Oregon this weekend have given us all something to ponder and marvel at.

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New Jersey Drone Sightings: Unraveling the Mystery

Published

3 days ago

December 18, 2024

Rod Washington

In recent weeks, New Jersey has increasingly found itself under the watchful eye of mysterious drones. These sightings have captivated residents and officials alike, leading to widespread speculation and calls for action. Below is a comprehensive update on the current situation regarding drone sightings in the Garden State, including insights from government officials and community reactions.

The Surge of Sightings

Reports of large drones—up to six feet in diameter—flying over various regions of New Jersey have surged since mid-November. Assemblywoman Dawn Fantasia highlighted the unusual characteristics of these drones, often flying with their lights off and evading detection by traditional methods. Though the origin and purpose of these drones remain unclear, many are convinced that they are not the product of hobbyists.

Notably, many sightings have been concentrated near sensitive locations such as the Picatinny Arsenal, a U.S. military research facility, and Trump National Golf Club in Bedminster. Concerns have only intensified since these drones seem to be operating outside the realm of normal commercial or recreational use.

Government Investigations and Assurances

Federal and state law enforcement agencies, including the FBI and the Department of Homeland Security (DHS), have become actively involved in investigating these sightings. Despite receiving over 5,000 tips, officials state that there is currently no evidence suggesting that these drones pose a threat to national security or public safety. Instead, authorities believe that many of the reported sightings can be attributed to legal drones and other aerial phenomena, including misidentified manned aircraft and even celestial bodies like stars.

Governor Phil Murphy has reinforced this perspective, emphasizing that while drone sightings have raised valid concerns, there’s no immediate threat to public safety. The governor has called for federal assistance in the investigation and urged Congress to empower states with more authority to manage drone activities.

Congressional Response and Public Sentiment

The situation has sparked a debate among lawmakers, with some calling for stricter regulations or even a temporary ban on drone flights in New Jersey. Notably, two congressional representatives have gone so far as to request that the military intervene, highlighting the urgency felt by some constituents. U.S. Rep. Jeff Van Drew even suggested that a foreign entity could be behind the sightings, a theory that has been categorically denied by federal officials.

Public sentiment varies significantly, with many residents expressing concerns about the unknown nature of these drones. James Edwards from Succasunna has pointed out the anxiety gripping the community, noting, “There’s so much that’s unknown,” and calling for a measured response to the sightings.

The View from Washington

At the national level, President Joe Biden has responded to the growing unease, asserting that there is nothing nefarious behind the drone sightings. He emphasized the lawful presence of over one million registered drones operating across the country and assured the public that the situation is being closely monitored.

John Kirby, the White House National Security Advisor, reiterated that the majority of drone sightings do not indicate a coordinated threat and stem from common commercial, hobbyist, or law enforcement operations.

What Lies Ahead?

As investigations continue, officials stress the importance of discerning legitimate threats from unwarranted fears. The situation remains fluid, with ongoing dialogues both in Trenton and Washington to address public concerns and craft appropriate regulatory responses.

While the mystery of the New Jersey drones deepens, it’s vital for residents to remain calm and informed. As the investigation unravels the truths behind these sightings, a collective effort from the community, lawmakers, and federal agencies can help ensure safety and transparency in the skies above New Jersey.

Stay tuned for updates as this story continues to evolve, and be sure to report any new sightings or information to the appropriate authorities. Together, we can navigate the complexities of drone activity in our airspace while embracing this new technological frontier.

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Learning from Voices of War: Honoring the 80th anniversary of World War II’s final major battle

Published

5 days ago

December 16, 2024

Daily News Staff

(Family Features) The Ardennes Offensive, commonly known as the “Battle of the Bulge,” stands as the single bloodiest battle fought by the United States during World War II. Waged in the bitter cold of mid-December 1944, it took the Allies a month to secure victory. The cost was staggering: nearly 20,000 Americans were killed in action, close to 50,000 wounded and another 20,000 captured.

In honor of the 80th anniversary of this pivotal battle, the Library of Congress Veterans History Project has launched an online exhibit to commemorate the milestone. While the battle itself is etched in the annals of history, the personal stories from those who endured it remain one of the most powerful testaments to its impact.

The online exhibit, “Serving Our Voices,” features accounts from 12 Battle of the Bulge survivors, part of the thousands of narratives preserved by the project. These stories ensure future generations can gain deeper understanding of veterans’ service and sacrifice.

One such story includes Eliot Annable, a 20-year-old radio operator serving with the Army’s 106th Infantry Division. Just days after arriving at the western front, Annable found himself under German artillery barrages on. Dec. 16, 1944. He recalled the assault in his oral history, describing the intensity as “almost enough to knock you on the floor.”

The following five days became the most harrowing days of Annable’s military service. While on a communications mission, he became stranded behind enemy lines and spent nearly a week evading the enemy in the Ardennes Forest without food, shelter or appropriate winter clothing. After traveling more than 30 miles, he eventually safely rejoined the remnants of his unit.

Back home, Annable’s parents were gripped by uncertainty. On Dec. 31, 1944, his father wrote a letter expressing the family’s anguish and love for their son, regardless of what happened. The moving letter, coupled with Annable’s oral history, provides an intimate view into one soldier’s Battle of the Bulge experience.

Another featured veteran in the exhibit, Guy Martin Stephens, also served with the 106th Infantry Division. Unlike Annable, Stephens was captured by the Germans during battle. In his oral history, he recounted the surreal feeling of combat, the relentless hunger he endured as a prisoner of war and the lingering effects of his time in captivity.

“It’s hard,” Stephens said. “It’s something you can’t ever … your mind is just like a video, or camcorder, I guess. You put it in there. You get busy and get married. You get home, and you get an education, and get a job, and raise your family and everything like that. You can kind of gloss it over or try to push it back, but it’s always there, you know?”

Veterans who served during the 20th or 21st centuries are invited to establish a collection, including interviews (video or audio), letters and original photographs, even if they did not see combat. Families can also submit collections posthumously to honor their loved ones. To explore more veterans’ stories and learn how you can contribute to the program, visit loc.gov/vets.

Photos courtesy of Library of Congress Veterans History Project

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SOURCE:
Library of Congress Veterans History Project