Articles tagged with Sediment
A CU-led study reveals worm burrows less than three inches above the K-T boundary layer, indicating they likely emerged shortly after the asteroid impact. The findings provide direct evidence of animal activity in a peat-producing environment that was buried by sediment.
Researchers studying Lake Agassiz, a massive lake that once covered much of Canada and the US, have found evidence suggesting that increased evaporation, not outflow, caused a significant drop in water levels during the Younger Dryas cold interval. This finding provides insights into climate change and its effects on global systems.
A chance viewing of a new channel forming in the Wabash River provided researchers with a rare opportunity to study dynamic river cutoffs. The event delivered massive amounts of sediment into the river system, changing its landscape and raising concerns about its impact on sediment transport and deposition processes.
New studies suggest that Arctic sea ice loss is not irreversible, while radiation hazards for spacefarers and air travelers are likely to rise due to solar activity. Researchers also predict an increase in space weather radiation events over the next century.
A recent study found high concentrations of polychlorinated biphenyls (PCBs) in the deep sediments of the Indiana Harbor and Ship Canal, posing a risk to human health and the environment. The discovery was made by researchers from the University of Iowa Health Care, who used submersible vibro-coring systems to collect sediment samples.
A USC researcher collected samples from floating sediment traps in the San Pedro Basin to study how much carbon is locked up in the ocean. Her findings suggest that the majority of particulate organic carbon falling to the basin floor is marine-derived, acting as a carbon sink taking carbon out of the atmosphere via phytoplankton and l...
A study published in Science found that the last interglacial period saw less melting in Greenland and more in Antarctica than previously thought. The researchers used sediment analysis to estimate past ice sheet behavior and improve future projections.
A scientist has discovered that a viral host can persist and coexist with the same genetic populations of a virus for centuries. The study, published in Science, reveals that DNA viruses and their algal hosts have been preserved in sediments under the Black Sea for thousands of years.
A study by Syracuse and Yale universities provides a clearer picture of the Earth's temperature approximately 50 million years ago. The researchers found that average Eocene water temperature along the subtropical U.S. Gulf Coast was around 27 degrees centigrade (80 degrees Fahrenheit), slightly cooler than earlier studies predicted.
USDA scientists found that non-pathogenic E. coli strains can survive longer in underwater sediments than in water, supporting the use of sediment as an indicator of fecal contamination. The study also revealed that higher levels of organic carbon and fine particles in sediment prolonged E. coli survival.
Researchers explore potential causes of widespread gullying on the southeastern Tibetan Plateau, find evidence of late Quaternary development in river valleys of the Karakoram Himalaya range. Paleovalley morphology studies reveal insights into climate and tectonic controls on sedimentation.
A newly constructed, 2,000-year history of sea level elevations will help scientists refine models used to predict climate-change-induced sea level rise. The record shows the past century had the fastest recorded rate of sea level rise.
Researchers found that ancient global warming, known as the Palaeocene–Eocene Thermal Maximum (PETM), saw slower rate of carbon emissions compared to current levels. The study suggests that humankind's carbon footprint may be accelerating modern climate change.
Hanadi Rifai will test parts of Galveston Bay for dioxins and PCBs to identify the source of pollutants and determine concentrations in marine life. Her findings will help state officials develop effective management strategies, including bioremediation and commercial fishing bans.
Scientists have discovered a new species of birch mouse ancestor, Sicista primus, which is 9 million years older than previously known and originated from Asia. The tiny fossil teeth found in sediments in Inner Mongolia provide evidence of the genus' persistence over time without significant morphological changes.
Researchers discovered a unique sequence of geologic events that triggered Japan's devastating tsunami, including an unusual 'two-faced' rupture on the fault plane and extreme dynamic overshoot. This finding highlights the need to better understand similar earthquakes in other subduction zones around the world.
A 2,300-year climate record reveals sharp drops in tropical monsoon rainfall since 1900, leading to severe droughts and water shortages. The study suggests that rising Northern Hemisphere temperatures are drawing the Intertropical Convergence Zone north, reducing rainfall on which tropical areas rely.
Researchers at the University of Gothenburg have developed a method to study lake-bottom sediments and infer fish death in acidified lakes. By analyzing microscopic remains of dead midge larvae, they can recreate the history of the lake back to the early 19th century.
A University of Arizona-led research team found that wind can be up to 100 times more effective at eroding mountains than previously thought. The study suggests that wind played a key role in shaping the Loess Plateau, with over half of its dust coming from the Qaidam Basin.
Researchers have found evidence suggesting humans settled in North America around 15,500 years ago, earlier than previously estimated. The discovery was made using optical dating technique at the Buttermilk Creek complex in central Texas.
Researchers used fossil coral reefs and sediment slides to detect historic earthquake patterns, creating an underwater map of the Red Sea floor. This method can be applied anywhere, including Japan and the west coast of the U.S., helping city engineers pinpoint high-risk locations ahead of potential earthquakes.
A new tool, developed by Prof. Shmuel Marco, can analyze wave patterns in sediment to understand past earthquake intensity. The 'fossil seismograph' helps geophysicists predict future earthquakes in areas with bodies of water.
New research reveals ancient 'megadroughts' in the Southwest US, which may be followed by a cooler period. The study used sediment cores to analyze past climate conditions and found similarities with present-day warming trends.
Researchers revived resting spores of diatoms that had lain dormant for over 100 years, showing they are genetically stable and can survive extreme conditions. The study found no significant genetic impact from external sources over the past century, highlighting the adaptability of these phytoplankton.
Scientists have unraveled the environmental changes in the Arctic during an ancient bout of natural global warming. The Paleocene–Eocene Thermal Maximum (PETM) led to a 15-metre succession of sediment representing a 170,000-year event, with sea level peaking about 13,000 years into the period.
Researchers confirm that stream bank failure is a significant contributor to high sediment levels in the Mississippi River, with seepage erosion playing a crucial role. The study finds that stable stream banks can become unstable when seepage erosion is added to factors promoting bank failure.
Research reveals fish produce fine-grained carbonates through their intestines, which are then excreted and released into the environment. This discovery sheds light on the origins of ancient limestone and chalk deposits.
Researchers reconstructed Arctic ocean conditions during Late Cretaceous greenhouse periods, finding periodicities matching modern Arctic climate influences. The findings suggest that natural modes of climate variability, such as ENSO and AO/NAO, may remain unchanged under global warming.
The STABCON project developed a cost-effective solution for treating polluted sediments in ports, using the stabilisation and solidification method. The method involves mixing contaminated sediments with products that bind them to create a solid material containing hazardous substances, reducing environmental harm and costs.
Studies reveal marine ferromanganese crusts as potential mineral resources, while CO2 emissions from volcanic lakes are also highlighted. Additionally, progressive uplift of the north Tibetan Plateau is confirmed since the middle Miocene, with implications for geological processes and catastrophic events.
A study using a 'fingerprinting' technique has identified the main sources of mercury in Bay Area fish, tracing it back to sediments and historic mining sites. The findings suggest that small fish acquire mercury from sediments and pass it along to larger fish, highlighting the need for targeted efforts to protect wildlife.
Researchers at UBC have created a global map of surface permeability, which could lead to new insights into water supply and climate modelling. The map, published in Geophysical Research Letters, provides critical data for managing groundwater resources and evaluating the impact of groundwater on climate.
Researchers found that the wave of mountain building swept down western North America as far south as Mexico and as far east as Nebraska. The data, from ancient precipitation, suggests a slow-motion wave of mountain-building coursing southward, with elevations up to 14,000 feet.
Deep sediment cores from the Bering Sea floor reveal an ice-free region with high biological productivity during the Pliocene Warm Period. The findings suggest that global temperatures were a few degrees higher than today and carbon dioxide levels comparable to current levels.
Global coastal wetlands are likely to disappear near the end of the 21st century, with limited sediment supplies and tidal ranges making them vulnerable. Wetlands with higher sediment availability may survive under slow sea-level rise projections.
Researchers study how changing winds in the Southern Hemisphere affect ocean carbon storage and atmospheric carbon dioxide. A new study finds large methane releases from ocean sediments during glacial periods could have impacted ocean chemistry and contributed to climate changes.
A new study reveals that tundra fires in Alaska's North Slope are linked to rising Arctic temperatures and nonlinear climate conditions. The research found a dramatic relationship between temperature and frequency of fires, with temperatures above 10 degrees Celsius increasing fire occurrence.
Researchers observe sills forming at shallow depths in sediment layers, releasing nutrient-rich fluids and significant amounts of CO2 and methane. This novel mechanism may influence ocean cycles and climate.
Researchers propose new techniques for analyzing methane hydrate structures, finding signs of life in iron-oxide-rich spheres and pipes near Escalante, Utah. The study also explores the impact of the Three Gorges Dam on the middle Yangtze, as well as a ~300-million-year-old bivalve shell.
A new study examines how river flow affects sediment movement, aiming to predict erosion and deposition in rivers. By using an innovative combination of measurements, scientists will improve understanding of sediment transport and develop techniques to prevent damage to infrastructure.
A team of scientists, led by URI oceanography professor Steven D'Hondt, will embark on a nine-week expedition to the South Pacific Gyre to drill into the basaltic basement and search for evidence of life. The team aims to test whether microbial communities can be sustained by hydrogen released from radioactive water decay.
Research at Uppsala University found a strong connection between lake sediment temperature and carbon dioxide production. A warmer climate is expected to increase carbon dioxide emissions by 4-27% over the next hundred years due to decreased organic carbon deposition.
Geologists found a lower density fault zone in the 2004 Sumatra earthquake, allowing it to slip over a longer segment and reach closer to the seafloor, generating larger tsunami waves. The study's findings could help improve hazard assessment and mitigation for this region.
Researchers studied the bacterial community structure in four environments of the Tablas de Daimiel National Park, revealing similarities and differences between them. The study found 265 new phylum groups, including those related to Proteobacteria, which are abundant in the superficial sediment sample.
Research from Imperial College London found that oil spills can partially block the ocean's natural filtration system, leading to increased arsenic levels in seawater. This can disrupt photosynthesis, genetic alterations, and animal life, creating a toxic threat to aquatic life and ecosystems.
A two-year field study found that compost filter socks reduced sediment concentration by 49% in runoff from tilled fields, but had no effect on no-till fields. The filter socks also decreased herbicide alachlor and glyphosate concentrations by 18% and 5%, respectively.
A team of researchers used aerial photographs and field measurements to analyze the Canyon Lake flood, which excavated a 2.2-kilometer-long canyon in just three days. The study offers insight into ancient megafloods on both Earth and Mars, with findings that challenge traditional views of river canyon formation.
New research reveals the Yangtze River in China is 40 million years old, challenging previous estimates of its origins. The study, published in Geology, found that the river began cutting the Three Gorges area around 45 million years ago, resulting in a more gradual formation process.
Researchers compiled a comprehensive history of Arctic ice using sediment cores and proxy data, concluding that the current extent is at its lowest point for at least the last few thousand years. The study's findings suggest the volume of ice is shrinking much faster than its surface area, highlighting a troubling trend in climate change.
Researchers present new slip rate estimates for the Alpine fault near Inchbonnie, New Zealand, yielding dextral, vertical, and reverse-slip rates of ~13.6, ~3, and ~3.4 mm/yr. These values have important implications for understanding plate boundary kinematics and comparing short-term strain with medium-term geologic rates.
A Queen's University study found that Arctic seabirds' diets can funnel toxic ocean metals to terrestrial ecosystems, affecting other organisms. The research analyzed sediment cores from two Canadian Arctic ponds and linked bird diets to specific metal contaminants.
Researchers found that bacteria in oxygen-free environments can use insoluble organic compounds to accelerate mineral respiration, a new pathway for electrical charges to move around in the environment. This discovery has implications for understanding soil chemistry and environmental contamination.
A University of Minnesota study reveals a significant increase in dioxin levels derived from triclosan in the Mississippi River sediment over the past 30 years, while other dioxins have decreased. The study also found that triclosan-derived dioxins account for about 30% of total dioxin mass in Lake Pepin sediments.
Researchers found evidence of four 'megafloods' in Glacial Lake Atna, which breached ice dams and released up to 1,400 cubic kilometers of water. The floods formed massive dunes over 110 feet high, with some still visible on topographical maps.
Researchers have uncovered two partial skeletons of a new Homo species, Australopithecus sediba, dating back to around 2 million years ago. The fossils are exceptionally well-preserved and provide significant insights into the evolutionary history of our genus.
A new study reveals that deep-sea scavengers outcompete smaller animals for food in ocean canyons, leading to reduced biodiversity. Larger animals sense the presence of food and converge on the canyon floor, devouring all available nutrients and leaving little for other animals.
A mega-flood from a giant ice sheet in North America triggered the Younger Dryas cold snap, causing Europe's temperatures to plummet. Fresh water mixing with the Arctic Ocean led to the shutdown of the Gulf Stream, resulting in prolonged glacial temperatures.
A Queen's University study has discovered high levels of mercury in the Cataraqui River sediment, with contamination widespread along the western shore.
Researchers created a miniature river delta to study flooding patterns and develop a mathematical model capable of predicting catastrophic floods. The model was able to reproduce the statistical behavior of flooding by analyzing how long it takes to fill a channel with sediment, allowing for enhanced flood hazard prediction.
A team of researchers, including UC San Diego's Richard Norris, presents new evidence linking an asteroid impact to the mass extinction that wiped out dinosaurs and other organisms 65.5 million years ago. The study highlights a unique layer of debris in deep-sea sediments that correlates with abrupt environmental changes.