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Categories: Paleontology: Climate, Physics: Acoustics and Ultrasound

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Absorbing excess sound to make public environments like theaters and concert halls safer for hearing and using the unwanted sound waves to create electricity is the aim of a new paper. The authors built a system of piezoelectric sensors that can be installed in walls, floors, and ceilings to absorb sound waves and collect their energy. They used computer simulations to fine-tune variables including the voltage needed to power the main device component, the frequency and intensity of the input sound, and piezoelectric sensors tested in parallel and serial configurations.

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Researchers have developed deep-learning algorithms that let users pick which sounds filter through their headphones in real time. Either through voice commands or a smartphone app, headphone wearers can select which sounds they want to include from 20 classes, such as sirens, baby cries, speech, vacuum cleaners and bird chirps.

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Past cold periods such as the Little Ice Age were associated with reduced strength of North Atlantic currents and increased surface salinity in the Caribbean. This was accompanied by disturbances in the distribution of salt to the north leading to longer, stronger cooling phases in the northern hemisphere.

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During the last ice age, the last glacial maximum about 20,000 years ago, the climate in the North Atlantic underwent much greater multi-centennial variability than it does in the present warm period. This is supported by evidence found in ice and seafloor cores. Researchers have now shown, based on a climate model, that internal mechanisms such as temperature and salinity distribution in the ocean are driving this multi-centennial variability.

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A new study takes an important step toward reconstructing a global history of water over the past 2,000 years. Using geologic and biologic evidence preserved in natural archives -- including 759 different paleoclimate records from globally distributed corals, trees, ice, cave formations and sediments -- the researchers showed that the global water cycle has changed during periods of higher and lower temperatures in the recent past.

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Researchers have mapped how land use changed across Britain throughout the last century. The new map reveals how and where some 50 per cent of semi-natural grassland was lost, including 90 per cent of the country's lowland meadows and pasture, as the nation intensified its agriculture.

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Researchers in the field of human-technology interaction have demonstrated how a custom-built 'data-to-music' algorithms can help to better understand complex data. The transformation of digital data into sounds could be a game-changer in the growing world of data interpretation.

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A new Antarctic ice sheet modeling study suggests that meltwater flowing out to sea from beneath Antarctic glaciers is making them lose ice faster.   

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The explosion of the underwater volcano Kolumbo in the Aegean Sea in 1650 triggered a destructive tsunami that was described by historical eye witnesses. A group of researchers has now surveyed Kolumbo's underwater crater with modern imaging technology and reconstructed the historical events. They found that the eyewitness accounts of the natural disaster can only be described by a combination of a landslide followed by an explosive eruption.

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Human populations in Neolithic Europe fluctuated with changing climates, according to a new study.

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Scientists analyzed open-source data to track vegetation changes across North America since the end of the Pleistocene Epoch, and conclude that humans have had as much of an impact on the landscape as the retreat of the glaciers at the end of the Ice Age. 

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A team has identified several factors to help answer a fundamental ecological question: why is there a ridiculous abundance of species some places on earth and a scarcity in others? What factors, exactly, drive animal diversity? They discovered that what an animal eats (and how that interacts with climate) shapes Earth's diversity.

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Meltwater that runs along the east coast of Greenland, hardly enters the open ocean before reaching the western side of the island.  In the changing climate, fresh water from Greenland and the Arctic could disrupt the circulation in the Atlantic Ocean.

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New research by climate scientists indicates that there have been great changes to Atlantic hurricanes in just the past 50 years, with storms developing and strengthening faster.

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Using lake sediment cores, scientists determined how these subalpine ecosystems recovered after 4,800 years of fire.

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Surface ice in Greenland has been melting at an increasing rate in recent decades, while the trend in Antarctica has moved in the opposite direction, according to researchers.

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71 of the 162 ice shelves that surround Antarctica have reduced in volume over 25 years from 1997 to 2021, with a net release of 7.5 trillion tons of meltwater into the oceans, say scientists.  They found that almost all the ice shelves on the western side of Antarctica experienced ice loss. In contrast, most of the ice shelves on the eastern side stayed the same or increased in volume.  Over the 25 years, the scientists calculated almost 67 trillion tonnes of ice was exported to the ocean, which was offset by 59 trillion tons of ice being added to the ice shelves, giving a net loss of 7.5 trillion tons. 

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As the climate warms, there is major concern that Earth's ocean will lose oxygen. A study has revealed that locked in ancient deep-sea sediments is evidence for oxygen loss in the world's ocean during past glacial periods, indicating that widespread oxygen loss with current climate change may not be permanent.    

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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.