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Categories: Geoscience: Earth Science, Physics: Acoustics and Ultrasound
Published West Antarctic Ice Sheet retreated far inland, re-advanced since last Ice Age
(via sciencedaily.com) Original source The West Antarctic Ice Sheet is melting rapidly, raising concerns it could cross a tipping point of irreversible retreat in the next few decades if global temperatures rise 1.5 to 2.0 degrees Celsius (2.7 to 3.8 degrees Fahrenheit) above preindustrial levels. New research finds that 6,000 years ago, the grounded edge of the ice sheet may have been as far as 250 kilometers (160 miles) inland from its current location, suggesting the ice retreated deep into the continent after the end of the last ice age and re-advanced before modern retreat began.
Published New research redefines mammalian tree of life
(via sciencedaily.com) Original source Scientists from around the globe are using the largest mammalian genomic dataset in history to determine the evolutionary history of the human genome in the context of mammalian evolutionary history. Their ultimate goal is to better identify the genetic basis for traits and diseases in people and other species.
Published Ecosystem evolution in Africa
(via sciencedaily.com) Original source New research pushes back the oldest evidence of C4 grass-dominated habitats in Africa -- and globally -- by more than 10 million years, with important implications for primate evolution and the origins of tropical C4 grasslands and savanna ecosystems across the African continent and around the world.
Published The future is foggy for Arctic shipping
(via sciencedaily.com) Original source As the Arctic warms and loses sea ice, trans-Arctic shipping has increased, reducing travel time and costs for international trade. However, a new study finds that the Arctic Ocean is getting foggier as ice disappears, reducing visibility and causing costly delays as ships slow to avoid hitting dangerous sea ice.
Published Is the ocean a solution for ushering in the era of environmentally friendly energy?
(via sciencedaily.com) Original source Researchers confirm the superiority of seawater batteries that use chelating agents.
Published Twilight zone at risk from climate change
(via sciencedaily.com) Original source Life in the ocean's 'twilight zone' could decline dramatically due to climate change, new research suggests.
Published Ocean ecosystem: Mixotrophic microorganisms play key role
(via sciencedaily.com) Original source Researchers have identified a previously unknown group of bacteria, called UBA868, as key players in the energy cycle of the deep ocean. They are significantly involved in the biogeochemical cycle in the marine layer between 200 and 1000 meters.
Published Lead vocal tracks in popular music go quiet
(via sciencedaily.com) Original source Scientists carried out an analysis of hundreds of popular song recordings from 1946 to 2020 to determine the lead vocal to accompaniment ratio, or LAR. The study considered the four highest-ranked songs from the Billboard Hot 100 chart for each year and the results show that, contrary to expectations, the LAR for popular music decreased over the decades in question. This means that, relative to their bands, lead singers are getting quieter.
Published Massive iceberg discharges during the last ice age had no impact on nearby Greenland, raising new questions about climate dynamics
(via sciencedaily.com) Original source New findings suggest that Heinrich Events had no discernible impact on temperatures in Greenland, which could have repercussions for scientists' understanding of past climate dynamics.
Published It's not as difficult as you think to shout upwind
(via sciencedaily.com) Original source Why does it feel so difficult to shout upwind? The sensation is common enough to have found its way into an idiom about not being understood. Researchers wanted a scientific explanation for the phenomenon -- and there wasn't been one. They have now shown that our common sense understanding of this situation is wrong. It isn't harder to shout into the wind; it's just harder to hear yourself.
Published A more precise model of the Earth's ionosphere
(via sciencedaily.com) Original source The ionosphere -- the region of geospace spanning from 60 to 1000 kilometers above the Earth -- impairs the propagation of radio signals from global navigation satellite systems (GNSS) with its electrically charged particles. This is a problem for the ever higher precision required by these systems -- both in research and for applications such as autonomous driving or precise orbit determination of satellites. Models of the ionosphere and its uneven, dynamic charge distribution can help correct the signals for ionospheric delays, which are one of the main error sources in GNSS applications. Researchers have presented a new model of the ionosphere, developed on the basis of neural networks and satellite measurement data from 19 years. In particular, it can reconstruct the topside ionosphere, the upper, electron-rich part of the ionosphere much more precisely than before. It is thus also an important basis for progress in ionospheric research, with applications in studies on the propagation of electromagnetic waves or for the analysis of certain space weather events, for example.
Published Algae in Swedish lakes provide insights to how complex life on Earth developed
(via sciencedaily.com) Original source By studying green algae in Swedish lakes, a research team has succeeded in identifying which environmental conditions promote multicellularity. The results give us new clues to the amazing paths of evolution.
Published Arctic ice algae heavily contaminated with microplastics
(via sciencedaily.com) Original source The alga Melosira arctica, which grows under Arctic sea ice, contains ten times as many microplastic particles as the surrounding seawater. This concentration at the base of the food web poses a threat to creatures that feed on the algae at the sea surface. Clumps of dead algae also transport the plastic with its pollutants particularly quickly into the deep sea -- and can thus explain the high microplastic concentrations in the sediment there.
Published Ridgecrest faults increasingly sensitive to solid Earth tides before earthquakes
(via sciencedaily.com) Original source Faults in the Ridgecrest, California area were very sensitive to solid earth tidal stresses in the year and a half before the July 2019 Ridgecrest earthquake sequence.
Published The climate crisis and biodiversity crisis can't be approached as two separate things
(via sciencedaily.com) Original source Anthropogenic climate change has, together with the intensive use and destruction of natural ecosystems through agriculture, fishing and industry, sparked an unprecedented loss of biodiversity that continues to worsen. In this regard, the climate crisis and biodiversity crisis are often viewed as two separate catastrophes. An international team of researchers calls for adopting a new perspective.
Published Using solar farms to generate fresh desert soil crust
(via sciencedaily.com) Original source Biocrusts play a crucial role in maintaining soil health and ecosystem sustainability, but they are currently under assault. Human activities including agriculture, urbanization, and off-road vehicle use can lead to the degradation of biocrusts, which have long-term consequences for these fragile environments. Climate change is also placing stress on biocrusts, which struggle to adapt to sunlight and searing heat in arid landscapes like the Sonoran Desert.
Published Turkey's next quake: Research shows where, how bad -- but not 'when'
(via sciencedaily.com) Original source Using remote sensing, geophysicists have documented the massive Feb. 6 quake that killed more than 50,000 people in Eastern Turkey and toppled more than 100,000 buildings. Alarmingly, researchers found that a section of the fault remains unbroken and locked -- a sign that the plates there may, when friction intensifies, generate another magnitude 6.8 earthquake when it finally gives way.
Published Water arsenic including in public water is linked to higher urinary arsenic totals among the U.S. population
(via sciencedaily.com) Original source A new study shows that water arsenic levels are linked to higher urinary arsenic among the U.S. population for users of both private wells and public water systems.
Published New USGS-FEMA report updates economic risk from earthquakes
(via sciencedaily.com) Original source Even though most of the economic losses are concentrated in California and along the West Coast due to that region's high seismic hazard levels, significant population, and building exposure, earthquake risk is spread throughout the country. For example, there is a combined $3.1 billion per year in projected losses across the central U.S., Rocky Mountain region, Alaska, Hawaii, Puerto Rico and the Virgin Islands.
Published Versatile, high-speed, and efficient crystal actuation with photothermally resonated natural vibrations
(via sciencedaily.com) Original source Mechanically responsive molecular crystals are extremely useful in soft robotics, which requires a versatile actuation technology. Crystals driven by the photothermal effect are particularly promising for achieving high-speed actuation. However, the response (bending) observed in these crystals is usually small. Now, scientists address this issue by inducing large resonated natural vibrations in anisole crystals with UV light illumination at the natural vibration frequency of the crystal.