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Categories: Geoscience: Geography, Physics: Acoustics and Ultrasound

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Researchers describe an acoustic meta-surface that uses pingpong balls, with small holes punctured in each, as Helmholtz resonators to create inexpensive but effective low-frequency sound insulation. The coupling between two resonators led to two resonance frequencies, and more resonant frequencies meant the device was able to absorb more sound. At the success of two coupled resonators, the researchers added more, until their device resembled a square sheet of punctured pingpong balls, multiplying the number of resonant frequencies that could be absorbed.

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With global warming apparently here to stay, a team of paleoclimatologists are studying an ancient source to determine future rainfall and drought patterns: fossilized plants that lived on Earth millions of years ago.

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A team found a way to deliver clear pictures of anyone's internal anatomy, no matter their skin tone.

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Due to the changing climate, the underwater world is getting ever noisier.

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Scientists using natural tracers off Queensland’s coast have discovered the source of previously unquantified nitrogen and phosphorus having a profound environmental impact on the Great Barrier Reef. Groundwater discharge accounted for approximately one-third of new nitrogen and two-thirds of phosphorus inputs, indicating that nearly twice the amount of nitrogen enters the Reef from groundwater compared to river waters.

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An international team of scientists have discovered a huge spike in radiocarbon levels 14,300 years ago by analyzing ancient tree-rings found in the French Alps. The radiocarbon spike was caused by a massive solar storm, the biggest ever identified.  A similar solar storm today would be catastrophic for modern technological society – potentially wiping out telecommunications and satellite systems, causing massive electricity grid blackouts, and costing us billions. The academics are warning of the importance of understanding such storms to protect our global communications and energy infrastructure for the future.

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Geologists have reconstructed a massive and previously unknown tectonic plate that was once one-quarter the size of the Pacific Ocean. The team had predicted its existence over 10 years ago based on fragments of old tectonic plates found deep in the Earth’s mantle. To the lead researchers surprise, she found that oceanic remnants on northern Borneo must have belonged to the long-suspected plate, which scientists have named Pontus. She has now reconstructed the entire plate in its full glory.

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The Gulf Stream is intrinsic to the global climate system, bringing warm waters from the Caribbean up the East Coast of the United States. As it flows along the coast and then across the Atlantic Ocean, this powerful ocean current influences weather patterns and storms, and it carries heat from the tropics to higher latitudes as part of the Atlantic Meridional Overturning Circulation.  A new study now documents that over the past 20 years, the Gulf Stream has warmed faster than the global ocean as a whole and has shifted towards the coast. The study relies on over 25,000 temperature and salinity profiles collected between 2001 and 2023.  

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Ocean currents determine the structure of the deep-sea ocean floor and the transport of sediments, organic carbon, nutrients and pollutants. In flume-tank experiments, researchers have simulated how currents shape the seafloor and control sediment deposition. This will help in reconstructions of past marine conditions.

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New research has revealed that since the 1980s, Category 4 and 5 hurricanes (maximum wind speed greater than 131 miles per hour) have been arriving three to four days earlier with each passing decade of climate change.

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A technology being studied to curb climate change – one that could be put in place in one or two decades if work on the technology began now – would affect food productivity in parts of planet Earth in dramatically different ways, benefiting some areas, and adversely affecting others, according to new projections.

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Winter is coming—eventually. And while the earth is warming, a new study suggests that the atmosphere is being pushed around in ways that cause long bouts of extreme winter cold or wet in some regions. The study’s authors say they have identified giant meanders in the global jet stream that bring polar air southward, locking in frigid or wet conditions concurrently over much of North America and Europe, often for weeks at a time. Such weather waves, they say, have doubled in frequency since the 1960s. In just the last few years, they have killed hundreds of people and paralyzed energy and transport systems.

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Scientists have found early human migrants left Africa for Eurasia, across the Sinai peninsula and on through Jordan, over 80-thousand years ago. Researchers have proved there was a 'well-watered corridor' which funneled hunter-gatherers through The Levant towards western Asia and northern Arabia via Jordan.

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New research has overturned the traditional view that natural rock weathering acts as a carbon sink that removes CO2 from the atmosphere. Instead, this can also act as a large CO2 source, rivaling that of volcanoes.

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Researchers working to image New Zealand's Hikurangi earthquake fault have uncovered a sea's worth of water buried in the Earth's crust. The water was carried down by eroding volcanic rocks and is believed to be dampening the earthquake fault, allowing it to release most of the pent-up tectonic stress through harmless slow slip earthquakes.

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Along the Asian coast lines there are many areas where rural communities experience alarming rates of sea level rises due to land subsidence up to 10 cm per year. This causes tremendous challenges on how to live there and protect these coasts. Scientists have now investigated the potential and limitation of mangrove restoration as a cost-effective and sustainable solution for coastal protection in rapidly subsiding areas.

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In a new study, researchers examined the waxy coatings of leaves preserved as organic molecules within sediment from the early-to-middle Holocene, a period of intense warming that occurred due to slow changes in Earth's orbit 11,700 to 4,200 years ago. They found that warming potentially could lead to a previously under-appreciated flux in methane emissions from lakes.

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New research suggests that ultrasound may have potential in treating a group of harmful chemicals known as PFAS to eliminate them from contaminated groundwater.

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Using an innovative new approach to sampling corals, researchers are now able to create maps of coral biochemistry that reveal with unprecedented detail the distribution of compounds that are integral to the healthy functioning of reefs.

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Paleontologists discover possible DNA remains in fossil turtle that lived 6 million years ago in Panama, where continents collide.