Articles tagged with Sediment
New evidence suggests that post-depositional 'burn-down' events in the Kimmeridge Clay Formation caused loss of organic matter, resulting in alternating patterns between organic-rich and -poor sediments. This supports the 'burn-down' theory over the long-held hypothesis of elevated planktonic productivity.
Researchers confirm high levels of PCBs in IHSC sediments, sparking concerns about dredging's environmental impact. The study highlights the need for further investigation into the effects of dredging on sediment PCB levels and potential health hazards to humans.
Researchers estimate that echinoderms, including starfish and sea urchins, produce over a tenth of a gigatonne of carbon per year through calcifying their skeletons. This contribution is more significant than previously thought and must be taken into account in climate models.
The study reconstructs environmental conditions on the Voring Plateau, indicating shallow marine environments in early Eocene and full submersion by late Eocene. This suggests earlier marine connections between Nordic sea basins, which may have contributed to declining global temperatures and ice sheet development.
Researchers employed a novel combination of geological and model reconstructions to address spatial variations in sea-level history along the east coast of England. Sediment compaction explained the variations in sea-level observations, revealing striking correlations to the thickness of overlying sediment.
An international team of scientists led by François Paquay found high iridium concentrations in sediments but could not replicate results. Additional lines of evidence failed to support an impact theory for the onset of the Younger Dryas cold period, contradicting a previously proposed conceptually appealing theory.
Researchers discovered that microorganisms can survive for thousands of years trapped in salt crystals, and a study found that river flood dynamics may not be recorded in marine deposits. Additionally, scientists analyzed volcanic eruptions and their impact on the environment.
A 14,000-year reconstruction of the past climate at Maxwell Bay in Antarctica reveals unprecedented regional synchronous warming and ice loss. The study suggests that current warming is linked to atmospheric trends associated with global climate change.
A PNAS paper reveals that dramatic changes in the Arctic began after the midpoint of the 20th century and are unprecedented. The unique sediment cores contain rare paleoclimate information about the past 200,000 years, providing a longer record than most other sediments.
Researchers are empowering Bengali women and children to identify contaminated water sources, helping them make informed decisions about where to dig wells. They're also providing testing kits to detect high levels of arsenic in the water.
Researchers propose diverting sediment-rich water from Mississippi River to create new land, compensating for projected losses and protecting upriver areas. The model predicts creating up to 45% of the anticipated new land area, with enough flow remaining in the main channel for navigation.
A team of researchers led by Queen's University scientists has discovered significant ecological changes in an Arctic lake, which extends the record of climate change back 80,000 years. The study found that human activities are overpowering natural processes, leading to dramatic ecosystem shifts.
Researchers analyzed sediment cores from a remote Arctic lake, finding unprecedented biological and chemical changes since the 1950s. Human-caused greenhouse gas emissions have overridden natural cooling processes, resulting in warming and altered ecosystems.
Recent studies uncover new insights into the Miocene structural reorganization of the South Tibetan detachment, eastern Himalaya, and its implications for understanding continental collision. Additionally, researchers have developed a one-dimensional modeling approach to quantify dip and velocity of continental subduction from high-pre...
A team of researchers found that some microscopic marine organisms recovered within a century after the mass extinction, contradicting previous estimates of millions of years. This discovery suggests that the atmosphere cleared quickly, allowing ecosystems to recover from the impact's effects.
A Purdue University study found that planting more corn for biofuels would lead to higher levels of nitrogen, fungicides, and phosphorus in nearby water sources. Continuous-corn rotations result in greater sediment losses, allowing these pollutants to enter the water.
Recent studies published in the November/December 2009 GSA Bulletin reveal insights into the Cenozoic tectonics of Nicaragua and the Median Trough, as well as the stratigraphic signature of late Cenozoic Antarctic Ice Sheets. The research also explores bivergent thrust wedges surrounding oceanic island arcs in the northeastern Caribbea...
A new study by CU-Boulder indicates most world's low-lying river deltas are sinking from human activities. Human-induced factors such as upstream sediment trapping and groundwater extraction exacerbate delta sinking, increasing flood risk and vulnerability to storms and sea level rise.
A team of scientists led by U of C grad Casey Hubert detected high numbers of thermophilic bacteria in subzero sediments in the Arctic Ocean. The bacteria may provide a unique opportunity to trace seepages of fluids from hot sub-seafloor habitats and potentially point towards undiscovered offshore petroleum reservoirs.
Researchers will drill through Lake Vida's thick ice cap to study the brine and sediment below, aiming to understand the ecosystem's history and its survival strategies in extremely cold conditions. The project, funded by a $1.1 million grant, may reveal insights into life on Earth dating back thousands of years.
Scientists have reconstructed Arctic summer temperature over 2,000 years using lake sediments, tree rings, and glacier ice. The study shows the last half-century was the warmest of the past 2,000 years, reversing long-term cooling trends.
Researchers found Arctic temperatures were cooler for 8,000 years before warming around 1900, reversing a natural cooling cycle. The study suggests human-caused climate change is the main cause of recent warming in the Arctic.
Scientists believe methane trapped under ocean may be escaping faster than previously thought through sea floor vents. The release could have significant implications for understanding the Earth's carbon cycle and global warming.
A team of researchers led by Mercyhurst College archaeologist James Adovasio has identified the most extensive delineation of submerged prehistoric river systems in the world. The team also found high-quality chert at three dive sites, which could be used to make tools by early Americans.
A new 2,000-year-long reconstruction of sea surface temperatures in the Indo-Pacific warm pool suggests temperatures may have been as warm during the Medieval Warm Period as they are today. This study contributes to scientists' efforts towards improving global temperature reconstructions.
A new study by LSU professor Patrick Hesp and USGS scientist David Rubin suggests that Titan's linear dunes could be formed by single-direction winds due to cohesive sediment. This alternative hypothesis has significant implications for studying Titan's composition, origin, evolution, and surface features.
A study by Duke University environmental engineers reveals that microbes can convert tiny mercury particles into methylmercury, a potent toxin for nerve cells, through reactions with organic matter and sulfides. This process is crucial in understanding how mercury enters the food chain and poses risks to human health.
Researchers reconstruct past hurricane activity in the Atlantic Ocean, indicating a high period of hurricane activity during the Medieval Climate Anomaly around AD 900-1100. The current low hurricane activity may be related to an emerging El Niño event, which can lead to more wind shear and fewer hurricanes.
Researchers from the National Oceanography Centre have made significant discoveries using iron isotopes to study sediment respiration and iron cycling processes in the deep-sea. The findings provide new insights into iron's role in the ocean's carbon cycle and its impact on climate.
Researchers at the University of Liverpool have discovered that the Amazon river and its transcontinental drainage are approximately 11 million years old. This finding has significant implications for understanding South American paleogeography and the evolution of aquatic organisms in Amazonia and on the Atlantic coast.
A Scripps-led study reveals that improving ocean health can accelerate coral reef recovery after bleaching events. Corals from reefs with clean water and abundant sea life bounced back to normal growth rates within two to three years.
A team led by University of Oregon archaeologist Douglas J. Kennett found shock-synthesized hexagonal diamonds in 12,900-year-old sediments on the Northern Channel Islands. The discovery suggests a significant cosmic impact during Clovis time and matches the extinction of multiple species.
Researchers studied an ancient global warming episode, known as the Paleocene-Eocene Thermal Maximum, which occurred 55 million years ago. They found that the estimated amount of carbon dioxide in the atmosphere during this event was less than previously thought, suggesting that other mechanisms contributed to the warming.
Scientists discover regular alternation of microscopically thin layers composed of distinct diatom assemblages, reflecting seasonal changes in the Arctic Ocean during the Late Cretaceous. This indicates exceptional abundances of diatoms adapted to stratified conditions, suggesting a pointer to future trends in the modern ocean.
A team of scientists found surprisingly few organisms beneath the seafloor of the South Pacific Gyre, with cell counts three to four orders of magnitude lower than at similar depths outside gyres. The sediment's oxygen levels were also unexpectedly high, supporting an aerobic community.
Fossils of land plants provide key insights into past climates, revealing that summer temperatures on land remained relatively warm during the Eocene/Oligocene transition, but with increasing seasonality. The researchers found that temperate climate trees such as spruces and hemlock replaced subtropical trees like palms and swamp cypress
Scientists have created a high-resolution climate record from ocean sediment dating back over 500,000 years, revealing four glacial cycles and the warming of North Atlantic waters. The record provides valuable insights into the extent of ancient ice sheets and their impact on ocean currents.
Recent research includes the documentation of Holocene rupture on major faults in Lake Tahoe Basin and evidence for a large paleolake in Western Desert, Egypt. A study on groundwater system in southern Colorado Plateau-Arizona Transition Zone also sheds light on seismic hazards in western Washington State.
Researchers explore Arctic river deltas as a potential source of information about past and future climate change. The sediments deposited in these delta regions can record data on sea level, productivity, storminess, and human factors affecting sediment delivery, providing valuable insights into the global carbon cycle.
Researchers have discovered evidence of pre-industrial mercury pollution in the Andes, dating back to 1400 BC, and challenge current thinking on the rise of mining societies. Mercury pollution was initially caused by mine dust from vermillion production, but later increased with Inca control of mines.
A new study by Woods Hole Oceanographic Institution and the University of California, Santa Barbara, has quantified oil residue in seafloor sediments from natural petroleum seeps off Santa Barbara. The oil content decreases with distance from the seeps, creating an 'oil fallout shadow'.
Researchers found that oil spills from petroleum seeps in the Santa Barbara Channel are mostly deposited on the ocean floor, with most of it being biodegraded. The study provides insights into the life cycle of oil spills and their impact on the environment.
Researchers have found drastic changes in sediment cores from river deltas worldwide, revealing past changes in nitrogen application, flooding, and hurricane events. The study highlights the importance of deltaic sediments as a 'history book' for understanding environmental changes, particularly in relation to climate change.
New research by Princeton University geoscientist Gerta Keller suggests that volcanoes, not an asteroid, were the likely culprits in the demise of the Earth's giant reptiles. The study found 'biotic evidence' and 'aftermath' sediments indicating a massive die-off occurred much later than previously thought.
Chevron-shaped dunes are not indicative of mega-tsunamis, contrary to popular speculation. Microbial life extends fossil record by 1.5 billion years, while nanoscale cristobalite fibers in volcanic ash hint at adverse health effects. The largest trilobites ever found provide insight into Earth's first animals and fossil evidence.
Recent studies focus on North Sister volcano's glaciated history and the largest radial dike swarm in the Cascades. Sediment waves along submarine channels are also examined in the Espirito Santo Basin, Brazil, while a new study reveals highly explosive eruptions at Kilauea Volcano, Hawai'i.
A new study found that changes in vegetation can override climate change effects on wildfire frequency. Plant types and abundance play a significant role in determining an ecosystem's flammability. In some cases, vegetation changes were more influential than climate shifts, leading to fewer fires.
Researchers at NC State University have found an exponentially better way to protect streams and lakes from the muddy runoff associated with stormwater around road and other construction projects. The alternative method uses natural fiber check dams enhanced with polyacrylamide, significantly reducing sediment loss and pollution.
Researchers at UNH found that sealcoat can contribute to high levels of polyaromatic hydrocarbons (PAHs) in waterways, posing a risk to aquatic life and potentially human health. The study showed significant increases in PAH concentrations in stormwater runoff from sealed parking lots compared to unsealed areas.
Scientists investigate possible tectonic cycling of serpentized peridotites in the Mariana forearc, connect Saddle Mountain and Seattle faults, and improve fractured carbonate-reservoir characterization with remote sensing. Seismic reflection profiles also define Grenville-age rift system and foreland basins beneath Phanerozoic sediments.
Researchers successfully retrieve DNA from ancient macrofossils up to 26,000 years old and dried museum beetle specimens up to 188 years old using a non-destructive DNA extraction method. This breakthrough has significant implications for population genetic studies and reconstruction of ancient biodiversity.
Researchers found that bacteria in the soil and sediment of river basins in Asia convert iron and arsenic into a form that readily dissolves in water, contaminating groundwater. This discovery has significant implications for policymakers trying to reverse the mass poisoning crisis.
A new study by León Paumen has improved the accuracy of risk assessments for soil and sediment contamination. The research found that prolonged exposure to Polycyclic Aromatic Compounds (PACs) can lead to unpredictable effects on life cycles, contradicting previous assumptions about gradual effects.
Rice University researchers found that pockets of ancient water may still exist under Olympus Mons due to the presence of clay sediments. This could provide a habitable environment for thermophilic organisms, which thrive near geothermal vents on Earth.
Researchers find methanol enhances uranium reduction in contaminated ground water and sediment. Methanol use results in almost complete uranium reduction compared to ethanol or glucose, suggesting potential for improved long-term bioremediation stability.
Scientists found that the mineral composition of these coatings can have a substantial effect on the retention of nitrate and sulfate. Understanding this mechanism is critical to protecting groundwater resources.
A dramatic rise in sea level occurred about 400,000 years ago, exceeding 21 meters above current levels. This finding has significant implications for understanding the impact of future climate change on coastal ecosystems and biodiversity.
A modeling study reveals that Katrina-flooded homes can harbor hazardous contaminants in the air, posing significant health risks to residents and first responders. The study identifies inhalation exposure routes through volatile and semi-volatile organic pollutants, highlighting the need for better preparation and safety protocols.
Scientists found that natural iron fertilization enhanced phytoplankton growth and productivity in the Southern Ocean, leading to two to three times more carbon export to the deep ocean. The research suggests that ocean islands are a key source of iron for these blooms.
Researchers suggest using 30% of global crop residues to sequester 600 megatons of carbon in the deep ocean, reducing atmospheric CO2 by up to 15%. The process would be 92% efficient and minimize environmental damage if done correctly.