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Categories: Anthropology: Cultures, Geoscience: Oceanography
Published Researchers studying ocean transform faults, describe a previously unknown part of the geological carbon cycle
(via sciencedaily.com) Original source This study reports widespread mineral carbonation of mantle rocks in an oceanic transform fueled by magmatic degassing of CO2. The findings describe a previously unknown part of the geological carbon cycle in transform faults that represent one of the three principal plate boundaries on Earth. The confluence of tectonically exhumed mantle rocks and CO2-rich alkaline basalt formed through limited extents of melting characteristic of the St. Paul's transform faults may be a pervasive feature at oceanic transform faults in general. Because transform faults have not been accounted for in previous estimates of global geological CO2 fluxes, the mass transfer of magmatic CO2 to the altered oceanic mantle and seawater may be larger than previously thought.
Published When the global climate has the hiccups
(via sciencedaily.com) Original source Climate changes usually happens over long periods of time, but during the last glacial period, extreme fluctuations in temperature occurred within just a few years. Researchers have now been able to prove the phenomenon also occurred during the penultimate glacial period.
Published Ice cores provide first documentation of rapid Antarctic ice loss in the past
(via sciencedaily.com) Original source Researchers have uncovered the first direct evidence that the West Antarctic Ice Sheet shrunk suddenly and dramatically at the end of the Last Ice Age, around eight thousand years ago. The evidence, contained within an ice core, shows that in one location the ice sheet thinned by 450 meters -- that's more than the height of the Empire State Building -- in just under 200 years.
Published Scandinavia's first farmers slaughtered the hunter-gatherer population, study finds
(via sciencedaily.com) Original source Following the arrival of the first farmers in Scandinavia 5,900 years ago, the hunter-gatherer population was wiped out within a few generations, according to a new study. The results, which are contrary to prevailing opinion, are based on DNA analysis of skeletons and teeth found in what is now Denmark.
Published What turned Earth into a giant snowball 700 million years ago? Scientists now have an answer
(via sciencedaily.com) Original source Inspired during field work in South Australia's Flinders Ranges, geoscientists have proposed that all-time low volcanic carbon dioxide emissions triggered a 57-million-year-long global 'Sturtian' ice age.
Published Innovation in stone tool technology involved multiple stages at the time of modern human dispersals
(via sciencedaily.com) Original source A new study illuminates the cultural evolution that took place approximately 50,000 to 40,000 years ago, coinciding with the dispersals of Homo sapiens across Eurasia. The insights gleaned from their examination of stone tool technology challenge the widely held notion of a rapid cultural and technological 'revolution' that enabled anatomically modern humans to surpass Neanderthals and other archaic humans. Instead, the research suggests a nuanced evolutionary process, unfolding gradually over an extended period, with changes occurring at various times. These findings challenge the conventional theory on the timing and nature of cultural transitions during this pivotal period in human history.
Published How kelp forests persisted through the large 2014-2016 Pacific marine heatwave
(via sciencedaily.com) Original source New research reveals that denser, and more sheltered, kelp forests can withstand serious stressors amid warming ocean temperatures.
Published Thailand's Iron Age Log Coffin culture
(via sciencedaily.com) Original source A mortuary practice known as Log Coffin culture characterizes the Iron Age of highland Pang Mapha in northwestern Thailand. Between 2,300 and 1,000 years ago, individuals were buried in large wooden coffins on stilts, mostly found in caves and rock shelters.
Published Small but mighty -- study highlights the abundance and importance of the ocean's tiniest inhabitants
(via sciencedaily.com) Original source New research sheds light on tiny plankton, which measure less than 0.02mm in diameter but can make up more than 70% of the plankton biomass found in the ocean.
Published Study challenges the classical view of the origin of the Antarctic Circumpolar Current and warns of its vulnerability
(via sciencedaily.com) Original source The Circumpolar Current works as a regulator of the planet's climate. Its origins were thought to have caused the formation of the permanent ice in Antarctica about 34 million years ago. Now, a study has cast doubt on this theory, and has changed the understanding of how the ice sheet in Antarctic developed in the past, and what this could mean in the future as the planet's climate changes.
Published Vitamin B12 adaptability in Antarctic algae has implications for climate change, life in the Southern Ocean
(via sciencedaily.com) Original source The algae P. antarctica has two forms of the enzyme that makes the amino acid methionine, one needing B12, and one that is slower, but doesn't need it. This means it has the ability to adapt and survive with low B12 availability. The presence of the MetE gene in P. antarctica gives the algae the ability to adapt to lower vitamin B12 availability, giving it a potential advantage to bloom in the early austral spring when bacterial production is low. P. antarctica takes in the CO2 and releases oxygen through photosynthesis. Understanding its ability to grow in environments with low vitamin B12 availability can help climate modelers make more accurate predictions.
Published Prehistoric mobility among Tibetan farmers, herders shaped highland settlement patterns, cultural interaction, study finds
(via sciencedaily.com) Original source Using advanced geospatial modeling to compare environmental and archaeological evidence, researchers found evidence that connects ancient mobility and subsistence strategies to cultural connections forged among Tibetan farmers and herders in the Bronze and Iron Ages -- adding to understanding of how and why ancient communities built social relationships and cultural identities across the extreme terrain in Tibet.
Published Tidal landscapes a greater carbon sink than previously thought
(via sciencedaily.com) Original source Mangroves and saltmarshes sequester large amounts of carbon, mitigating the greenhouse effect. New research shows that these environments are perhaps twice as effective as previously thought.
Published Engineers unmask nanoplastics in oceans for the first time, revealing their true shapes and chemistry
(via sciencedaily.com) Original source Millions of tons of plastic waste enter the oceans each year. The sun's ultraviolet light and ocean turbulence break down these plastics into invisible nanoparticles that threaten marine ecosystems. In a new study, engineers have presented clear images of nanoplastics in ocean water off the coasts of China, South Korea and the United States, and in the Gulf of Mexico. These tiny plastic particles, which originated from such consumer products as water bottles, food packaging and clothing, were found to have surprising diversity in shape and chemical composition.
Published Unprecedented ocean heating shows risks of a world 3°C warmer
(via sciencedaily.com) Original source New research examines the causes of the record-breaking ocean temperatures witnessed in 2023.
Published As sea otters recolonize California estuary, they restore its degraded geology
(via sciencedaily.com) Original source As sea otters recolonize a California estuary, they are restoring its degraded geology by keeping populations of overgrazing marsh crabs in check, a new study shows. The crabs' appetite for plant roots, and their tunneling behavior had caused many of the estuary's marshes and creekbanks to erode and collapse in the otters' absence. Today, erosion has slowed by up to 90% in areas with large otter populations and marshes and streambeds are restabilizing.
Published Neanderthals and humans lived side by side in Northern Europe 45,000 years ago
(via sciencedaily.com) Original source Archaeologists have debated whether Neanderthals or modern humans made stone tools that are found at sites across northern Europe and date from about 40,000 years ago. A new excavation at one site in Germany turned up 45,000-year-old bone fragments that, when analyzed for mitochondrial DNA, proved to be from Homo sapiens. This is the earliest evidence that modern humans overlapped with Neanderthals in northwest Europe, thousands of years before Neanderthals went extinct.
Published Geoengineering may slow Greenland ice sheet loss
(via sciencedaily.com) Original source Modeling shows that stratospheric aerosol injection has the potential to reduce ice sheet loss due to climate change.
Published New research shows how pollutants from aerosols and river run-off are changing the marine phosphorus cycle in coastal seas
(via sciencedaily.com) Original source New research sheds light on how pollutants from aerosols and river run-off are impacting coastal seas. The research identified an 'Anthropogenic Nitrogen Pump' which changes the phosphorus cycle and therefore likely coastal biodiversity and associated ecosystem services.
Published Some plastic straws degrade quicker than others
(via sciencedaily.com) Original source Not all plastics are created the same, and some last longer in the ocean than others. Scientists have been working for years to quantify the environmental lifetimes of a wide range of plastic goods to see which have the shortest and longest lifespans in the ocean. To determine what plastics persist in the ocean, the team tests different products in large tanks that recreate the natural ocean environment.