Articles tagged with Sediment
Research on River Deba sediment pollution reveals the impact of anthropogenic inputs and flooding events on metal distribution. The study found a clear increase in organic matter and metals between the headwater and mouth of the river, with highly polluted sediments reflecting upstream pollution.
Researchers are drilling sediment cores from Lake Towuti on Sulawesi, which date back a million years or more, to reconstruct the climate history of the region. The sediments hold signatures of the hydrological cycle and can help scientists test climate model predictions.
Researchers found eight major flood events in the central Mississippi River valley that contributed to Cahokia's emergence and decline. The study suggests that floods disrupted agricultural settlement patterns, leading to increased population density and farming intensity.
Researchers found that H. azteca from polluted sites are less sensitive to pyrethroid insecticides than lab-grown ones. This suggests standard testing methods may not accurately reflect environmental health
Scientists found that sediment size in Himalayan river is larger during summer monsoon, revealing relationship between landslides and erosion. The study suggests that coarse material may be lost en route to the ocean, raising questions about sediment origins.
A recent study published in Geology has shown that parrotfish play a pivotal role in providing the sands necessary to build and maintain coral reef islands. The research found that parrotfish produced over 85% of the new sand-grade sediment on reefs around island communities in the Maldives.
The Mississippi Delta is facing an uncertain future due to the combined effects of sea-level rise and land subsidence. The study uses precise GPS data and tide gauge records to measure subsidence rates, revealing that parts of the delta may not be viable in the long term.
Scientists have developed a method to analyze uranium isotopes to determine whether bacteria were active in forming sediments billions of years ago. This new approach gives researchers a unique tool to study microbial activity and environmental niches from the past.
Researchers used PET/CT scans to study the behavior of lugworms in sediment, revealing how they burrow and interact with their surroundings. This technique provides insights into the ecological models of benthic animals, highlighting the importance of understanding their activities for maintaining ocean health.
Scientists at UiT The Arctic University of Norway have discovered a new source of methane in the Arctic Ocean, abiotic methane formed by chemical reactions in the oceanic crust. This finding challenges previous assumptions about the origin of methane and suggests vast systems of methane hydrate throughout the Arctic.
Researchers analyzed seabed samples off the coast of Turkey and found six large earthquakes in the area between 136 and 1896 AD. The study assigns past earthquakes to specific segments of the North Anatolian Fault, shedding light on the recurrence rate of earthquakes near Istanbul.
A massive 30-foot-long core sample of Pacific Ocean seafloor has shown that marine ecosystems can take thousands of years to recover from climate-related upheavals. The study analyzed over 5,400 invertebrate fossils and found that ecosystem recovery from climate change and seawater deoxygenation might take place on a millennial scale.
A study published in Geobiology reveals that methane production in thermokarst lake sediments can increase up to three times when exposed to higher temperatures. The findings suggest that biological methane production may play a larger role in total methane emissions in the future.
A new study by UC Davis researchers finds that ocean ecosystems can take thousands of years to recover from rapid climate change, with the recovery period being on a millennial scale. The study analyzed fossilized ocean fauna and found that even minor changes in oxygen levels could result in dramatic changes for seafloor communities.
Researchers found evidence of repeated climate fluctuations 1.4 billion years ago, reflecting changes in wind patterns and ocean circulations driven by orbital forcing of climate change. The study sheds light on how past climate changes have affected Earth geologically and biologically.
Scientists have analyzed seabed sediments to reconstruct past climates in the Mediterranean basin over 20,000 years. The study found reliable markers for wind patterns, fluvial cycles, and oxygenation conditions, shedding light on climate change.
A study analyzing Napa quake damage found that pre-1950 buildings in the sedimentary basin suffered the most severe shaking. The West Napa fault system, a lesser-known fault, triggered extensive damage to residential and commercial buildings.
Scientists found evidence of historically unprecedented hurricane activity along the northern East Coast of the United States, with sediment deposits on Cape Cod revealing 23 severe hurricanes between 250 and 1150. These prehistoric hurricanes were likely category 3 or 4 storms that would be catastrophic if they hit the region today.
A new study reveals that intense hurricanes, possibly more powerful than any storms in recorded history, frequently pounded the US Northeast between 250 and 1150. The findings could have implications for future hurricane intensity and frequency as ocean temperatures increase due to climate change.
A team of scientists has found evidence of methane seepage from the Arctic seabed dating back 2.7 million years, tied to tectonic plate movement and potentially influenced by past temperature fluctuations. The study suggests that the release of methane gas hydrates in this region may have contributed to climate change.
A new FSU study finds that 6-10 million gallons of oil are buried in the sediment on the Gulf floor, contaminating the food web and affecting marine life. The researchers used carbon 14 as an inverse tracer to determine the oil's distribution, revealing a significant amount still lingering on the seafloor.
Researchers found evidence of regional drought between 500 and 1150 AD in Mexico, contributing to the abandonment of Cantona, a large fortified city with a population of 90,000 inhabitants. The study suggests that climate change played a role in the site's history, highlighting the interplay of environmental and political factors.
The study reveals that dam-induced changes in riverine sediment transport lead to reduced oxygen levels, causing hatched pallid sturgeon embryos to die. The research provides vital information for pallid sturgeon conservation and is a significant breakthrough in understanding the species' decline.
A new study reveals that a small variation in sea level can stall coral reef growth and sediment production, contradicting the long-held notion of continuous reef formation. The research found that most lagoon infilling occurred over just four thousand years before being 'turned off' by a relatively small sea level fall.
Tropical Cyclone Bansi reached a Category 4 status, stirring up ocean sediment around the Cargados Carajos Shoals. NASA's Aqua satellite captured images of the sediment on January 19, showcasing the storm's powerful winds.
A study published in Forest Ecology and Management found that salvage logging increases sediment in water runoff, causing erosion and damage to fish habitats. Leaving slash on the ground, breaking up equipment trails with water bars, and replanting vegetation are recommended best management practices for minimizing ecological effects.
Researchers have found hazardous levels of mercury hundreds of miles downstream from Peruvian gold mines, contaminating local soil, sediment, and water resources. The study highlights the widespread impact of artisanal small-scale gold mining on human health and the environment.
A new study by the University of Waterloo has found that heavy metal emissions from Alberta's oil sands have not increased contaminant levels in the Athabasca River, despite concerns from local communities. The research developed a novel approach to determine pre-industrial baseline levels of metals in river sediment.
Researchers found that rates of hillslope erosion before European settlement were about an inch every 2500 years, while during peak land disturbance in the late 1800s and early 1900s, rates spiked to an inch every 25 years. This indicates a 100-fold increase in soil loss due to human activities.
Researchers analyzed data from the 2008 Wenchuan earthquake and found that sediment in affected river catchments remained for decades, longest where landsliding was highest. They also discovered low friction in the fault zone, contradicting previous observations.
Research reveals four billion microscopic plastic fibres littering each square kilometre of deep sea sediment worldwide. Microplastics have sunk to the ocean floor, with levels up to four times greater in deep seas than in shallow and coastal waters.
Researchers from PNNL present studies on persistent cold air outbreaks, sequestered carbon leaks in drinking water, and the environmental impacts of carbon sequestration. The team aims to collaborate between environmental and health science communities to better understand how the environment affects human health.
Scientists have found that the Arctic Ocean's sea ice cover began to form around 2.6 million years ago, with significant expansion occurring around this time. This new knowledge can be used to improve future climate models and predict potential ice-free periods, which could have major implications for the planet's climate system.
A team of geoscientists discovered a buried canyon beneath the Yarlung Tsangpo River, which helped reconstruct the gorge's geological history. The findings show that rapid tectonic uplift, not river capture, formed the Tsangpo Gorge and its steep form.
The Lake Van drilling project provides a unique 600,000-year archive of climate fluctuations and natural hazards, including six cycles of warm and cold periods. The analysis reveals the region's high risk for earthquakes and volcanic eruptions.
Researchers found that sediment concentrations in plumes from dredging or floods can delay clownfish larvae development by up to two weeks. This delay has a significant impact on adult populations as it increases the risk of mortality for young fish during their most vulnerable stage.
Hurricane Gonzalo stirred up ocean sediment off Bermuda's coast, as captured by NASA's Aqua and Terra satellites. The satellite imagery revealed sediment streaming east and south of the island.
Researchers found dramatic differences in flow velocity patterns and forces on river beds between gravel and sandy models, disproving a popular theory. The study's new parameters improve predictive models for nutrient and pollutant transport and provide insight into organism behavior in the narrow zone where rivers meet their beds.
Researchers have found that carbonate rocks contain vast amounts of active microbes that take up methane, expanding our understanding of the Earth's methane process. The discovery could significantly impact our understanding of greenhouse gas accumulation and its role in climate change.
A new study reveals that Earth's magnetic field reversed direction in less than 100 years, approximately 786,000 years ago. This rapid reversal could have significant effects on our planet, including disruptions to electrical grids and increased cancer rates due to the loss of protection from solar and cosmic particles.
A study by Oregon State University found that rivers can return to a condition close to their natural state after dam removal, with the biological recovery process often surpassing physical recovery. The continued presence of a dam is more significant than the sediment pulse caused by dam removal, according to researchers.
A Duke University team found that nanoparticles called single-walled carbon nanotubes accumulate rapidly in wetland sediments, potentially harming aquatic food chains. The accumulation of these nanoparticles in sediment poses concerns for both sediment-dwelling organisms and animals that eat them.
The Greenland Ice Sheet is more sensitive to climate change due to the role of soft ground beneath it, which affects its dynamics and leads to increased ice loss. This study reveals that the ice sheet is vulnerable not only to warming temperatures but also to extreme meteorological events like heavy rainfall and heat waves.
A team of scientists led by Jeremy Venditti used oceanographic instruments to study flow through steep bedrock canyons on the Fraser River. They discovered a complicated flow field with high velocity flow plunging down canyon walls, resulting in greater flow force applied to the bed.
Researchers found microplastics in nearly every sediment sample from the St. Lawrence River, with concentrations rivaling those in the world's most contaminated ocean sediments. The discovery raises concerns about the potential impact of microplastics on freshwater ecosystems.
Researchers discovered microplastic particles in the form of polyethylene microbeads in St. Lawrence River sediments, with concentrations exceeding 1000 per liter. The findings raise concerns about fish and other animals consuming these particles, potentially transferring chemicals to the ecosystem.
Despite visible signs of recovery, Cape Cod's saltmarshes are not fully restoring their ecosystem functions. A new study found that recovering marshes provide only partial benefits in terms of wave exposure and sediment height, while always-healthy marshes continue to offer superior coastal protection.
Researchers discovered evidence of Sahara dust affecting Lake Rio Seco in Sierra Nevada 11,000 years ago, indicating a relatively humid period during the Holocene. The study also revealed an aridification tendency and increased atmospheric dust fall in the Iberian Peninsula.
Researchers in southern Africa used beryllium-10 and aluminum-26 to measure erosion rates, finding five meters per million years in non-tectonically active regions. This rate is significantly lower than basin-average erosion rates, with stable upland surfaces remaining unchanged since the Pliocene.
A team led by Jill Mikucki finds microbial ecosystems in Subglacial Lake Whillans, supporting a diverse ecosystem that functions in the dark at subzero temperatures. The discovery has implications for life in extreme environments on Earth and in the solar system.
A new study suggests that burrowing animals played a key role in stabilizing the Earth's oxygen reservoir around 540 million years ago. The research, published in Nature Geoscience, links data from the fossil record to established connections between the phosphorus and oxygen cycles.
A new study suggests that the synchronization of North Atlantic and North Pacific climate variability preceded abrupt warming and the end of the last ice age. The researchers found that the combined warming of the two oceans provided a tipping point for rapid melting of northern ice sheets.
Researchers estimate four to five large earthquakes occurred on the Seattle fault or related faults during the past 3,500 years. The study uses geologic data and new field evidence to reconstruct earthquake patterns in the Puget Lowland, a structurally complex region.
Researchers found more than twice as much coral disease at dredging sites compared to control sites, highlighting a direct link between dredging and coral disease. Dredging impacts corals by reducing light for photosynthesis and interfering with feeding, leading to chronic stress and increased disease prevalence.
A new study reveals that a warming period over 400,000 years ago caused the Greenland ice sheet to deglace and raise global sea levels by 4-6 meters. The research uses sediment core analysis to track the chemistry of glacial stream sediments, providing insights into the history of ice sheets in Greenland.
Researchers analyze fossil assemblages from Ohio buhrstone to determine its provenance, revealing characteristics that distinguish it from French buhrstone. The study sheds light on the use of non-destructive techniques in studying ancient artifacts, with potential applications for understanding the origins of other tools.
The Antarctic Ice Sheet began melting 5,000 years earlier than thought, with eight distinct episodes causing rapid sea level rise. The study provides solid evidence that the ice sheet contributed to meltwater pulse 1A, a period of rapid sea level rise.
A study reveals that bottom trawling causes intensive biological desertification of sedimentary seabed ecosystems, leading to a 50% decrease in meiofauna abundance and 25% decline in nematode species. The practice also depletes organic matter and carbon content, threatening ecosystem functioning.
A new study suggests that a natural limiting switch exists in ocean systems, preventing the development of unchecked hypoxic areas. This cutoff switch is triggered by the formation of iron sulfides when oxygen levels approach zero.
A team of researchers has discovered the oldest human skeleton in North America, dating back 13,000-12,000 years. The skeleton, named Naia, was found in an underwater cave in Mexico and shows a shared genetic code with modern Native Americans.