Articles tagged with Sediment
The Three Gorges Dam in China is shrinking the Yangtze delta due to sediment retention. Meanwhile, a new model suggests that massive methane releases from Arctic permafrost are unlikely in this century. Satellite data also reveals complex flood wave patterns in the Amazon River, which can improve hazard identification. Additionally, hi...
Two studies suggest that the melting of the Greenland ice cap could significantly affect ocean circulation, leading to substantial changes in global climate. The authors analyze sediment records from past glacial periods, finding that sudden episodes of ice sheet melting may cause abrupt climate instability.
A recent study reveals that sediments in New Orleans and Lake Pontchartrain are contaminated with fecal microbes, which persisted before the hurricanes and continue to impact water quality. The researchers recommend further investigation into the risks of exposure to human pathogens through contact with these sediments.
A new study by the University of Miami Rosenstiel School found high levels of bacteria and pathogens in water and sediment samples from New Orleans and Lake Pontchartrain after Hurricanes Katrina and Rita, emphasizing the importance of rapid environmental assessments. The study suggests that sediments can pose a risk to public health d...
A record-setting Antarctic ice core extracted during a recent drilling expedition provides unprecedented detail on the Ross Ice Shelf's history, indicating fluctuations of up to 50 times over the last 5 million years. The research project, ANDRILL, aims to understand the impact of global warming on oceans worldwide.
Researchers found that burrowing behavior, escape response, and population abundance of salt marsh fiddler crabs are significantly altered when exposed to leftover oil compounds from a 1969 spill. The study provides clear evidence for the long-term impacts of oil pollution on marine ecosystems.
Scientists reconstructed land temperatures in tropical Africa over the past 25,000 years using a new method based on soil bacteria molecular fossils. The results show that tropical Africa was cooled more than the Atlantic Ocean during the last ice age, leading to drier conditions and a lush rainforest.
Researchers at University of Bonn aim to tap into the sediment archives of Lake Van, which store climate data from 800,000 years ago. The sediments contain detailed information on temperature and precipitation patterns, allowing scientists to reconstruct past climates.
Researchers discovered a sediment wedge beneath the Whillans Ice Stream in Antarctica, which provides stability against moderate sea level rise. The wedge, eroded by moving ice sheets, helps maintain the grounding line's location despite changes in relative sea levels.
The study challenges conventional thought on sediment transport in the GBR, showing large plumes of terrestrial material traveling up to 65-130km beyond the inner reef. This poses new risks for reef corals and highlights the need for rethinking hydrological modeling.
Researchers propose an alternative hypothesis for pingo-like features forming underwater: methane hydrate decomposing beneath the seafloor releases gas, squeezing up sediments. Geologic fieldwork and chemical analysis suggest warming seafloor sediment triggers decomposition of buried hydrates.
The study reveals that sediment folding may have contributed to the massive 2004 Sumatra tsunami. The unusual shape of the upper plate boundary, resembling a suspension bridge, created an area with multiple peaks and valleys that amplified water displacement when the plate snapped back.
Scientists study correlations between solar energy and global ice volume, finding inverse trends that challenge previous studies. They also investigate decomposing methane gas hydrates on the Arctic Shelf, suggesting a possible link to pingos and subsidence.
Researchers have gathered quantitative temperature data from arctic lake sediments and glaciers, revealing temperatures five degrees warmer than today. This finding provides a climate analogue to inform future predictions, highlighting the exceptional magnitude and rate of warming in the Arctic.
New research suggests that changes in midge communities provide evidence of global warming. Midge populations shifted dramatically over the last three decades, with warmer-water midges outcompeting cooler-water species.
The discovery of Little Foot, an Australopithecus fossil, has been revised to be around 2.2 million years old, pushing it back from earlier estimates of 3-4 million years. The findings suggest that Little Foot is a distant cousin rather than a direct ancestor of humans.
Researchers collected river water and sediment samples from Alaskan rivers during spring floods to study interactions with the coastal Beaufort Sea. The study found variations in river composition and flow, as well as under-ice mixing with sea ice and seawater.
Researchers propose that microorganisms can thrive in the Deep Biosphere due to natural radioactivity, offering an alternative energy source. This process, radiolysis, creates hydrogen and oxygen, providing sufficient energy for life forms to survive without surface processes.
Scientists from the Integrated Ocean Drilling Program (IODP) are making significant discoveries in ocean drilling operations, including the first complete section through a modern cold-water coral mound. The IODP is an international scientific research program that explores subseafloor environments and monitors environmental change, ge...
New research reveals that every US Gulf Coast bay in Texas and Louisiana is at risk of significant flooding and expansion within the coming century. The bays' delicate balance between river-borne sediments and rising sea levels will be disrupted by the construction of dams, leading to rapid flooding events with devastating consequences.
Tiny Pacific 'housekeeper' crabs play a crucial role in preventing coral death by removing sediment from coral surfaces. Without these crabs, corals experience slower growth rates, increased tissue bleaching, and higher sediment loads.
New evidence suggests Bering Strait flooded into Arctic Ocean 11,000 years ago, challenging traditional view of human migration from Asia to Americas. Sediment cores collected from Chukchi Sea reveal high resolution records of climate change and sea level rise.
Ocean scientists have made a groundbreaking discovery that microbes in deeply buried sediments produce energy-laden gases, including ethane and propane. This finding challenges traditional theories on the origin of these gases, which are typically associated with fossil fuel generation.
A new XRF Core Scanner will analyze sediment cores quickly without physical damage, providing fast insight into past geological events and current environmental state. This technology is based on a similar X-ray technology used to explain the collapse of the Classic Mayan civilization.
Researchers have characterized a gutless worm that relies on microbial specialists for energy production, waste handling, and transportation through marine sediments. The unique partnership involves the worm providing housing and nutrients to microbes in exchange for essential services.
Researchers at Princeton University claim the Earth's magnetic field suggests a massive tilt occurred about 800 million years ago. This 'true polar wander' event could have shifted entire continents, producing mysterious geochemical changes in ancient oceans.
The IODP Arctic Coring Expedition has provided new evidence that the Arctic was extremely warm and ice-free up to 55 million years ago, during the Paleocene/Eocene thermal maximum. This period saw a massive release of greenhouse gases, leading to significant temperature rises and changes in ocean chemistry.
Scientists at Harvard University discover deep-sea sediments can permanently store man-made carbon dioxide, with US seafloor holding vast reserves. The method involves injecting CO2 into sediment layers, creating a stable and secure storage system.
Aerial mosquito spray increased the toxicity of pyrethroids in creeks by doubling their effects. Researchers found that a chemical synergist, piperonyl butoxide (PBO), made sediments more toxic to certain aquatic species.
Researchers discovered a connection between catastrophic freshwater release from glacial lakes in North America and dramatic cooling in climate records approximately 8200 years ago. The study found that the freshwater forcing led to changes in deep ocean currents, which in turn affected northern hemisphere climate.
Scientists from the Integrated Ocean Drilling Program have recovered sediments that indicate prevailing ice conditions during the last 14-16 million years. The study also found evidence of ice in the Arctic Ocean dating back 45 million years, while temperatures rose to subtropical levels 55 million years ago.
New evidence from a 430-meter sediment core reveals glaciers in the Arctic Ocean formed simultaneously with those in Antarctica, rewriting climate history. The discovery underscores the role of greenhouse gases in driving global climate change.
A study by Markus Harting found that glass spherules from Mexico to Haiti match the chemical composition of rocks melted at Chicxulub. The reworked spherules are misplaced in sediments close to the K-T boundary, casting doubt on previous timelines.
A new method using ultrasound and genetically modified algae can remove up to 60% of mercury from contaminated water, according to Ohio State University researchers. The technique uses ultrasonic waves to release mercury from sediments, which is then absorbed by the algae, leaving the sediment clean.
Seagrass beds are diminishing globally, with human activity identified as the primary cause. The root system of these flowering plants stabilizes sediments and provides habitats for numerous marine species.
A study published in BMC Biology found that Oklahoma salamanders metamorphose into more terrestrial adult forms in fine, tightly packed gravel streambeds and retain juvenile forms in large, loosely packed particles. The researchers discovered a strong negative correlation between small streambed sediments and paedomorphosis.
Researchers found a sizeable and active archaeal community in deep sediment layers using energy from breaking down methane molecules. These microbes live on the slow side, requiring less energy to maintain and taking longer to divide than expected.
Researchers from the Marine Biological Laboratory (MBL) will present studies on rivers' impact on the Arctic Ocean, as well as microbial diversity in a sewage-impacted estuary. Additionally, scientists will discuss how ocean particle scavenging is modulated by surface ocean productivity and nutrient quality.
A Dartmouth research study confirmed earlier findings that toxic metals like arsenic and lead remain in the top 10 inches of soil after pesticide use. The new study reveals these metals are now part of the fine silt and organic matter, increasing erosion risk to nearby waters.
Scientists warn of a similar climate shift as the Paleocene-Eocene Thermal Maximum, which occurred 55 million years ago. The rate of carbon dioxide emission is now faster than natural processes can absorb, potentially triggering abrupt changes.
Researchers found that sediment-filled basins in subduction zones can strengthen the edge of the plate above, increasing the likelihood of large earthquakes. The Cascadia subduction zone is particularly prone to severe shaking due to its forearc basins, which can be up to 3 miles deep.
The USGS and ICDP successfully retrieved a nearly complete set of core samples from the Chesapeake Bay impact crater, allowing for unprecedented understanding of post-impact sediments and rocks. The recovered core will enable researchers to study global sea-level changes and the distribution of water-bearing units in the coastal plain.
Researchers reconstructed the Indus River's discharge over 30 million years and found a significant change in sediment source five million years ago. The study suggests that rivers were diverted from their original southeasterly flow by uplifted mountain ranges in modern-day Pakistan.
Researchers suggest that Martian features can be explained by meteorite strikes rather than evaporated lakes. Base surges from massive explosions caused by meteorite impacts result in simple and consistent explanations for rock formations and sediment layers found at the Opportunity site.
The CHIKYU drillship, operated by JAMSTEC, has completed its first coring operations in the ocean. Two piston cores, 50 meters and 70 meters long, were retrieved from 1,200-meter water depths, revealing olive-grey diatomecious mud with ash layers and potentially absorbing CO2 density levels.
The North Magnetic Pole's movement may be part of a normal oscillation and will eventually migrate back toward Canada. Scientists tracked the pole's movement using sediment records from Arctic lakes, providing a reliable timeline and revealing a 'jerk' in the magnetic field every 500 years.
A Rutgers-led team reports a steady millimeter-per-year rise in sea levels from 5,000 years ago until about 200 years ago, contrasting with the current two-millimeter annual increase. The findings argue against widely held tenets of geological science and provide a new baseline for addressing global warming.
Marine biogeochemists have shown that microbes degrading organic carbon respond differentially to temperature changes, affecting organic matter breakdown efficiency. This finding suggests that global climate change could influence the efficiency of organic carbon recycling and burial.
The IODP Expedition 311 has discovered gas hydrate deposits with higher concentrations found in coarse-grained sand layers throughout core samples. The findings will fundamentally change how scientists investigate the impact of gas hydrate deposits, revealing a more complex occurrence than previously predicted.
Researchers uncover fossils of two new species, Biretia fayumensis and Biretia megalopsis, in Egypt's Fayum desert, dating back 37 million years. The discoveries confirm that the common ancestor of humans, monkeys, and apes originated in Africa, with one species appearing to be nocturnal.
A two-year, $1.5 million project will provide fundamental information about sediment translocation in Venice lagoon, using a multidisciplinary approach to analyze geochemical, physical, microbial, toxicological, and ecological science. The research aims to assess the effects of sediment movement on the lagoon's ecosystem.
Deep-sea organisms rely on 'sinkers', discarded mucus nets of larvaceans, as a vital food source. Researchers found that these cast-off 'houses' carry large amounts of detritus and tiny animals towards the seafloor.
A team of scientists found that the oceans took tens of thousands of years to recover from a massive carbon dioxide release during the Paleocene-Eocene Thermal Maximum. The study suggests that the recovery time for current fossil fuel emissions could be similar, highlighting the need for urgent action.
Scientists have found that strain is rapidly accumulating within a specific area south of the San Gabriel Mountains in Los Angeles, primarily in the San Gabriel and San Fernando Valleys. The study suggests that the Puente Hills Fault and nearby faults may be more likely to break than others, increasing the risk of earthquakes.
Researchers from Columbia University and NASA used sediment layers to uncover a 500-year drought from 800 A.D. to 1300 A.D., as well as the effects of the Little Ice Age and European settlers' agricultural practices on the area's climate. The study found increased erosion, saltier water, and changes in vegetation during these periods.
A new study published in Geology estimates the maximum possible earthquake magnitude in the San Fernando and Northridge areas of Los Angeles County. The researchers used paleomagnetism to analyze sediments and found that the crust is broken into blocks, limiting the maximum earthquake magnitude to around 6.8.
Researchers found conditions unfavorable for methane gas hydrate formation in the northern Gulf of Mexico due to salt domes and hot sediments. The study suggests deposits may be thin or non-existent, contradicting previous estimates.
Researchers mimic seafloor conditions to study methane hydrate formation and decomposition, aiming to identify safe extraction methods. The study's findings may help develop strategies to tap into locked-up methane reserves.
Scientists discover that tubeworms release waste sulfate to stimulate sulfide-producing microbes, enabling their remarkable 250-year lifespan. This symbiotic relationship helps the worms thrive in deep-sea environments where nutrients are scarce.
Researchers have re-dated the Omo hominids fossils to approximately 196,000 years old, nearly 40,000 years older than previously thought. The discovery provides new insights into early human evolution and migration patterns.