Articles tagged with Sediment
Scientists discovered that the Atlantic Ocean's connection to the global thermohaline circulation occurred at a climatic tipping point around 59 million years ago. This enabled a more efficient distribution of heat over the planet, marking the end of a long-term cooling phase and the beginning of a new greenhouse period.
A 3,980-year-old volcanic eruption on Deception Island had a Volcanic Explosive Index of 6 and ejected 30-60 cubic kilometers of ash. The caldera collapse triggered a seismic event and had significant climatic impacts in the southern region.
Researchers found that overwintering Microcystis cells in sediments can seed the next year's bloom, explaining the rapid increase in Lake Erie bloom size and spatial extent. The study advances scientists' understanding of the basic biology driving the annual summer blooms.
Researchers discover Levallois cores in Asia dating back 80,000 to 170,000 years, challenging the notion of East Asian technological lag. The independent emergence of this complex toolmaking technique supports the idea that ancient civilizations in the region were capable of innovation.
A study has found that rising atmospheric CO2 levels could disrupt the sedimentary balance of beach-dune systems, leading to erosion and increased flooding risks. The research suggests that by 2100, sediment accumulation at the base of Mediterranean dunes could fall by 31%, putting beaches like San Giovanni in Sardinia at risk.
A new study analyzing one million years of precipitation history has found that the South Asian Monsoon is more complex than previously thought. The research team discovered that warming in the southern hemisphere and moisture transport across the equator play a crucial role in the monsoon's wind and precipitation patterns.
Scientists have reconstructed the monsoon's precipitation history over the past 1 million years using sediment cores from the eastern Indian Ocean. The results show that the monsoon was weaker during peak ice ages and strongest during interglacial warm periods, with fluctuations in the Earth's axis inclination playing a subordinate role.
A new study suggests that a warmer world may equal a wetter Arctic, driven by two climatic processes: melting sea ice and increasing global humidity. Researchers analyzed lakebed mud dating back thousands of years to uncover clues about the region's past climate.
Researchers discovered a new projectile point style at the Debra L. Friedkin site in Texas, dated between 13,500 and 15,500 years ago, earlier than typical Clovis-style technologies. The finding may indicate two separate human migrations into North America, challenging current understanding of peopling history.
Researchers from Georgia State University discovered arid conditions in East Africa around half a million years ago, which may have influenced human evolution and the development of stone technology. The findings provide insights into how environmental changes impacted early human ancestors.
Bioavailable iron in glacial dust supports phytoplankton growth and enhances climate feedback by removing carbon dioxide. During glacial periods, 25-45% of iron is bioavailable, whereas interglacial periods have only 5-10%.
Researchers at Ca' Foscari University of Venice identified and dated traces of sterols in Lake Diamond and Kirkpatrick sediments, proving the presence of the Maori people. The study demonstrates a method for reconstructing human history by analyzing fecal sterols, which also shows the impact of the Maori population on the native forest.
Dr. Panos Diplas, a Lehigh University professor, has been elected as an ASCE Fellow for his distinguished work in civil engineering and research on river phenomena such as scour and meandering. His team's studies aim to improve bridge stability and mitigate the effects of river movement on ecosystems.
Researchers found that Dutch delta plain's unique history can inform management of modern deltas, which face similar challenges like land subsidence and sea level rise. Human activities such as reclamation and agricultural expansion triggered the formation of new rivers along courses that natural branches would not have taken.
Researchers found evidence of a skeleton in ancient organisms, challenging previous assumptions about fossil chronicle. The discovery confirmed that these creatures had a skeleton composed of single-row chambers, similar to modern giant protozoa.
Researchers reconstructed three centuries of sedimentation history for NYC marshes, finding a significant decrease in inorganic mineral sediments since the 19th century. This reduction weakens marsh structures, suggesting future preservation will require adding mineral sediment to dredged basins and the marshes themselves.
A global study predicts that coastal wetlands will increase in area as sea levels rise, but only if humans preserve room for them to migrate inland. The researchers found a key threshold of 20 people per square kilometer, and suggest using 'natural and nature-based features' to expand accommodation space.
A recent study published in the Geological Society of America Bulletin suggests that the end-Permian mass extinction may have occurred in only 31,000 years, making it an instantaneous event by geological standards. The sudden extinction was likely caused by Siberian flood-basalt eruptions and local intensive explosive volcanism.
A new study reveals that East Antarctic Ice Sheet may melt under 2°C of sustained warming, posing a threat to global sea levels and human civilization. The research found that ice loss from the EAIS likely contributed to higher sea levels in the past.
A recent study by Alfred Wegener Institute researchers found that the loss of Arctic permafrost through coastal erosion led to significant increases in carbon dioxide concentrations in the atmosphere during the last glacial period. This phenomenon is now being studied to understand its potential impact on future climate warming.
Oregon researchers developed a new approach to capture the physical processes controlling glacier flow, shedding light on how sediment influences sliding speed. This improvement will help create more accurate ice flow models and forecast sea levels.
Organic matter sulfurization can occur on the timescale of just hours to days, according to new research published in Nature Communications. This process may have sizable implications for understanding the past and future of the Earth's climate.
Scientists found four pivotal strengthening events in the East Asian summer monsoon between 1250-1900 CE, with ocean sediments offering a more reliable record of past monsoon signals. The study provides insights into Asian monsoon dynamics and their impact on regional societies.
A new study led by Ohio State University found that algae poses a greater threat to freshwater fish vision than sediment, causing a 40% decrease in their ability to see in cloudy water. This could jeopardize the future of walleye and other fish populations if harmful algal blooms persist.
Researchers found that African killifish can mature and reproduce in as little as two weeks, setting a new record for the fastest maturation rate in vertebrates. The fish's lifespan is also highly flexible, with some individuals reaching sexual maturity in up to 10 weeks.
A Montana State University biochemist will study the role of microorganisms in breaking down and converting complex carbon compounds in the deep sea. The research aims to provide a benchmark for the field of deep-sea sediment microbiology and lay the foundation for future physiological studies.
Researchers map San Gabriel and San Bernardino sedimentary basins in greater detail than previous studies, revealing the San Gabriel basin is deeper and has an irregular shape. The study provides new insights into the structure of these basins, which may act as a 'waveguide' to focus energy from earthquakes.
A new study of lake sediments reveals that increased westerly winds are likely to reduce the Southern Ocean's ability to absorb carbon dioxide from the atmosphere. This could accelerate climate change as the Southern Ocean currently absorbs over 40% of human-produced carbon dioxide.
Researchers have dated a significant assemblage of stone artifacts at the Gault site in Central Texas to 16-20,000 years of age, identifying an early projectile point technology unrelated to Clovis. This finding pushes back the timeline of the first human inhabitants of North America before Clovis by at least 2,500 years.
A new study reveals that warming streams and rivers can significantly increase greenhouse gas emissions, particularly in agricultural lowland areas. The research highlights the need for land management strategies to reduce sediment rich in organic matter content and decrease groundwater abstraction.
Researchers developed a new approach to measuring recreational water quality, focusing on the quantity and type of mammalian feces in the water. They found that ecosystem-specific characteristics, such as freshwater sediment and estuary transport, also play a significant role in determining enterococci concentrations.
A research team from Woods Hole Oceanographic Institution found the fingerprint of a massive flood of fresh water in the western Arctic, which is believed to have caused an ancient cold snap around 13,000 years ago. The cause of this event, known as the Younger Dryas, has remained a mystery for decades.
A team of researchers re-examined 30 locations with reported accelerated erosion after glacial-interglacial cycles and found that nearly all proposed links to global climate could not be confirmed. Climate-induced accelerations were recorded only in three cases, driven by localized glacial-valley incision.
A landmark study published in Nature Geoscience reveals the Great Barrier Reef has suffered five death events over 30,000 years due to variations in sea level and associated environmental changes. The reef adapted by migrating up and down the seafloor, demonstrating remarkable resilience.
Researchers will study lake sediments in western Svalbard to identify sedimentary signatures of recent changes, potentially leading to more flash flooding and landslides. The study aims to provide a long-term perspective on modern climate conditions and their effects on the region.
A team from Woods Hole Oceanographic Institution has studied the Ayeyawady River delta's history, showing how its floodplains and shorelines have grown and shrunk over the past 10,000 years. The study reveals that shifts in monsoon climate have changed the shape of the delta.
Researchers discovered that microorganisms in the sediment are extremely active and produce about 90% of the methane released from mud volcanoes. The study found that chemical processes play a smaller role in methane production, indicating that mud volcanoes have a significant impact on the global methane cycle.
Researchers have found that certain colloids can stick to sediment grains due to decorative nanoscience, allowing for predictable attachment and removal of contaminants. This discovery could help improve prediction of contaminant transport distances and protect water resources.
A lake sediment record near the Greenland Ice Sheet margin preserves sediments from past interglacial periods, including the Early Holocene and Last Interglacial Period. July air temperatures during these periods were estimated to be significantly warmer than modern temperatures.
The research team aims to understand how the Irrawaddy-Salween Delta will respond to expected changes in sediment supply and coastal dynamics due to climate change and human development. They are using field studies and computer modeling to characterize where sediments accumulate and the mechanisms that move them.
A landmark international study found the Great Barrier Reef is more resilient to sea-level rise and temperature changes than thought, but highly sensitive to sediment input and poor water quality. The reef's ability to survive is uncertain due to current stresses and projected future changes.
A study published in PLOS ONE found microplastics at all 16 sites studied in Baynes Sound and Lambert Channel, with highest contamination in Henry Bay and Metcalfe Bay. The researchers identified three main types of microplastics: microfibers, microbeads, and microfragments, with microbeads being the most common type.
Researchers studied the Grand Caillou mound in coastal Louisiana, uncovering a timeline of natural and human events that shaped its construction and abandonment. The study provides insights into how Native peoples selected their villages' locations, using methods such as sediment coring and radiocarbon dating.
Fecal stanols, organic molecules found in sediment, provide a more accurate clue to past population sizes. The study found Cahokia's population peaked early and slowly declined, contradicting collapse theories.
A new model by Florida State University researcher Jaap Nienhuis can help stakeholders figure out what factors to consider when rebuilding land in fragile wetlands. The model takes into account various factors such as water and sediment discharge, root strength, and soil consolidation.
Researchers validate the geologic time scale by matching magnetic polarity sequences with detrital zircon ages from a long sediment core. The correlation supports assumptions about planetary interactions used to construct the APTS for hundreds of millions of years.
A new study discovered a 'feedback loop' in freshwater lakes where organic matter from plants suppresses methane production, while debris from trees and aquatic plants promotes its release. The findings suggest that changes in vegetation could lead to a doubling of lake emissions and exacerbate climate change.
Researchers at Nagoya University developed a method to analyze concretions using L-shaped cross-plot diagrams, revealing that they grow quickly due to the presence of organic matter. The study found that concretions can preserve well-preserved fossils of soft tissues, which are rarely fossilized under other conditions.
Scientists from GFZ and universities reconstructed past changes in Earth's magnetic field using paleomagnetic data. They found that the South Atlantic Anomaly is unlikely to be a precursor of a pole reversal, as it was followed by increased field strength and disappearance of similar anomalies in the past.
Research found that aquatic plants contribute significantly to long-chain n-alkanes in lake sediments, particularly in closed lakes. The study used hydrogen isotope composition to distinguish between terrestrial and aquatic sources, providing new insights into reconstructing ancient lake dynamics.
Human activities significantly impacted the Yangtze River's channel evolution between Datong and Xuliujing. Erosion with a volume of 4.7 hundred million cubic meters occurred due to decreased sediment discharge following the Three Gorges Dam closure.
A new Tulane University study using optical dating found that the rate of land building from river diversions will be dwarfed by wetland loss. The study suggests positioning diversions in areas with greatest potential for land-building and protecting population centers.
Researchers at KAIST have identified flammable ice formed in oceans through clay minerals in sedimentary deposits. They proposed a new principle for gas hydrate formation and found that electric fields can promote hydrate nucleation.
Geographers from FAU investigate ancient dust deposits to draw conclusions about settlement structures, crops, landscape changes, and climate fluctuations. The study aims to understand the cultural growth and decline of the Southern Levant region between the Iron Age and Byzantine period.
A recent study revealed a dramatic rise in extreme floods on the Mississippi River over the past century, largely due to human modifications such as artificial levees. The research also uncovered a link between flooding and natural fluctuations in Pacific and Atlantic Ocean water temperatures.
A new study reveals the Mississippi River Delta is experiencing seafloor erosion at an alarming rate, threatening marine ecosystems and infrastructure. The research, published in Marine Geology, found that sediment deposition has stopped, leading to land loss and degradation of wetlands and seafloors.
A sediment core from Sluice Pond has identified a layer of light brown organic-rich mud deposited between 1740 and 1810, suggesting an underwater landslide possibly triggered by the 1755 Cape Ann earthquake. The discovery provides new evidence for historic seismic activity in New England.
A new model simulates sediment transport and coral reef development in response to climatic variability. The study reveals that high sediment loads prevented coral growth during early sea level rise, while a balance between climate, sea level, and physiography enabled reefs to thrive.
New research pushes back the first glaciation and early human appearance in central Germany by 100,000 years. The study used luminescence dating to determine the age of river deposits containing Lower- and Middle Paleolithic stone artefacts.
A new study calculates a 'speed limit' for nitrate removal in streams, allowing for tailored restoration efforts to maximize its removal and protect ecosystems. The researchers found that the rate of nitrate transport by turbulence controls its removal in pristine streams, but processes within sediment prevail in polluted ones.