Articles tagged with Sediment
Arjun Heimsath, a Dartmouth College researcher, measures dynamic land movement by calculating erosion rates in different parts of the world. Using cosmic isotopes extracted from rock and sediment samples, he determines how long material has been there and how fast it's eroding or breaking down.
Researchers found that small island rivers in Taiwan and New Zealand produce high amounts of sediment, potentially impacting global climate change. The amount of sediment varies greatly between rivers, with the Cropp River in New Zealand producing 32,000 tons per square kilometer.
Geologists have identified the ancient harbor of Troy by correlating sedimentary facies with ancient texts, including Strabo's Geographies. The findings will be presented at the Geological Society of America's annual meeting in Boston.
Scientists discover the lower Hudson River estuary is slowly cleaning itself due to tidal forces, storms, rain, and spring runoff stirring up polluted sediment. The process transforms contaminants into less toxic forms, allowing them to be released out to sea.
The Vetlesen Foundation has awarded a grant to the University of Rhode Island Graduate School of Oceanography for the acquisition of equipment for studying sediment cores in global change research. This funding will enable researchers to further understand climate history and processes that may influence future changes.
Researchers at ONR and DARPA are developing OSCAR, an oceanic fuel cell that harnesses organic matter in sea sediments to generate electricity. The early versions of OSCAR have been generating about 50 milliwatts per square meter, sufficient power for small calculators.
Research suggests climate shifts, such as droughts and temperature changes, may be more important than carbon dioxide levels in determining plant community composition. The study analyzed sediment cores from Mexico and Guatemala, finding that trends in C3 versus C4 plants were correlated with shifts in rainfall rather than carbon dioxide.
Researchers have discovered a way to link specific microbes to the oxidation of methane in anoxic marine sediments using molecular and stable isotope techniques. This partnership between archaea and sulfate-reducing bacteria extracts energy from methane, removing nearly 80% of the methane in marine sediments.
A team of scientists analyzed sediment core samples from Lake Titicaca in Bolivia and Peru, revealing a 25,000-year precipitation record that suggests tropical South America was wet during the last Ice Age. The findings challenge traditional views that the region was dry during this time period.
Researchers analyzed ancient sediments to shed light on ancient drought cycles and their potential link to future aridity. The study found well-defined 80- to 100-year cycles of alternately arid and humid conditions in the region.
Researchers found a potential for water trapped in sediments to surge out and cause undersea landslides that can produce tidal waves. The study suggests a new explanation for expulsive events in the continental slope along the East Coast, potentially triggering landslides without warning.
Researchers discovered strong evidence of a 55.5 million-year-old global warming event linked to a massive methane release. The 'latest Paleocene thermal maximum' led to the extinction or disappearance of deep-sea species and changed ecosystems. Further research is needed to understand this phenomenon.
A new analysis by University of Colorado at Boulder professor Karl Mueller indicates a high threat of large earthquake in the New Madrid seismic zone. The study gathered evidence on a pivotal 'blind-thrust' fault and found a slip rate of nearly 45 feet over 2,300 years, posing significant risks to Memphis and St. Louis.
Researchers discover microbes convert saturated hydrocarbon hexadecane to methane and carbon dioxide, leading to potential methane formation in old sediments. This process, known as microbial hydrocarbon 'cracking,' sheds light on slow yet globally relevant microbial processes in deep subsurface environments.
Researchers found that soil erosion has been steadily decreasing since the 1930s, with erosion now at a mere 6% of its peak during the Dust Bowl era. The study's findings suggest that conservation efforts are working and watersheds are more intricate than previously thought.
A team of researchers has discovered the largest bacteria ever known, Thiomargarita namibiensis, which stores elemental sulfur and nitrate. The finding provides firmer evidence of coupling between the sulfur and nitrogen cycles in the ocean, offering new insights into the environment's recycling processes.
Biologists found Thiomargarita namibiensis in sediments off Namibian coast, living up to 3/4 mm wide and storing nitrate in an 'anaerobic lung'. The bacteria can survive for three months without external supply of nutrients, playing a crucial role in oxidizing toxic sulfide.
A University of Southern California study found that DDT and PCBs are widely distributed in the Palos Verdes Shelf water column, leaching from sediments. The substances' concentrations decreased exponentially with distance from the ocean floor, indicating they're being transported by ocean currents.
Researchers discovered brief, rapid warming episodes at the end of the last Ice Age that melted glaciers and affected Great Lakes climate. These events may be linked to El Nino Southern Oscillation and Quasi-Biennial Oscillation.
Research at Johns Hopkins University suggests that fur traders' hunting habits may have changed the local ecosystem, altering stream flow and vegetation. The study aims to understand how human activities affect natural resources and inform future development plans.
A 2,000-year-old climate warming event was discovered in East Africa by analyzing sediment cores from a high-altitude lake. This study suggests that the climate can warm up suddenly without human activity, providing new insights into past climate fluctuations and potentially informing predictions about future climate change.
Studies show a significant increase in PAHs in reservoirs and river sediments in suburban areas of major cities, contradicting efforts to reduce pollution. Urbanization is linked to the accumulation of these carcinogenic compounds, which are typically not detectable in water samples.
Researchers found evidence of regular climate shifts, including sudden cold snaps and warming periods, in ocean sediment cores from the North Atlantic. The 1,500-year cycle, which occurred every 1,470 years, may be the pacemaker of rapid climate change.
A team of researchers from Penn State is investigating the connection between sedimentation patterns at the river's mouth, land use patterns in the basin, and climate variability. They plan to analyze sediment cores using lead isotope ratios and pollen to link core layers with climate and sedimentary regimes.
Researchers find massive methane deposits in Blake Ridge area, equivalent to 35 billion tons, and estimate 7% of global carbon stored. The discovery suggests a significant role in past climate change and potential for future energy source.
Two USGS studies investigate endocrine disruption in carp, finding significant differences in sex steroid hormones and vitellogenin across regions. Pesticide concentrations were also detected in higher levels in certain waterways, raising concerns about the impact of environmental contaminants on fish populations.
Researchers will use Logging While Drilling technology to sample physical and chemical properties of rocks and sediments on the ocean floor. They aim to determine the age, composition, and physical properties of the area's rocks and sediments, as well as understand why some areas have low heat flow.
Marine geologists find detailed marine record of late Pleistocene era fires on land, shedding light on natural burning's impact on climate and ecosystems. The study reveals charcoal from fires on land was transported to ocean sediments via winds and rivers.
Researchers developed a new sediment basin design that reduces silt removal by using a skimmer system. The system removed 37 pounds of soil during simulated events, outperforming other methods tested.