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Unraveling the climate behind the collapse of Bronze Age civilizations

Phys.org: Earth science - Fri, 07/24/2026 - 18:00

The most severe droughts in the ancient Eastern Mediterranean arose when multiple natural climate cycles coincided, according to a new study from Stockholm University published in Science Advances. The findings shed new light on the climate conditions surrounding the Late Bronze Age collapse and may help improve understanding of future drought risks in a warming world.

Researchers develop AI-driven method to improve forecasts weeks in advance

Phys.org: Earth science - Fri, 07/24/2026 - 15:40

Haonan Chen, a CSU associate professor of electrical and computer engineering, and his team have published research that could improve the accuracy of precipitation forecasts up to two weeks in advance.

Fossilized wood reveals 300 million years of Earth's history

Phys.org: Earth science - Fri, 07/24/2026 - 14:00

Many people are familiar with fossilized wood as a decorative item from a museum shop. However, the fact that it can preserve the geological history of entire regions spanning millions of years is a new discovery. A research team led by geologist Dr. Steffen Trümper from the University of Münster has now demonstrated for the first time that fossilized wood is a natural archive from which the geological history of an entire region over hundreds of millions of years can be deduced.

Can ocean chemistry be altered to absorb carbon? The pros and cons

Phys.org: Earth science - Fri, 07/24/2026 - 14:00

As the planet warms, countries around the world are racing to meet their net-zero targets set out in the 2015 Paris Agreement.

Small tropical islands face dangerous humid heat by end of the century

Phys.org: Earth science - Fri, 07/24/2026 - 11:20

Millions of people living on tropical islands could face a future of increasingly dangerous heat as climate change drives longer and more intense periods of humid conditions. While rising temperatures are often discussed as the main consequence of climate change, humidity plays a crucial role in determining how much heat the human body can tolerate. When the air is already full of moisture, sweat evaporates less effectively, making it harder for people to cool down.

Statistical theory of electronic degrees of freedom in wave packet molecular dynamics

Physical Review E (Plasma physics) - Fri, 07/24/2026 - 10:00

Author(s): Daniel Plummer, Pontus Svensson, Wiktor Jasniak, Patrick Hollebon, Sam M. Vinko, and Gianluca Gregori

We derive statistical distributions for the degrees of freedom in wave packet molecular dynamics models. Specifically, a theory is developed for the width distributions of Gaussian wave packets in both isotropic and anisotropic formulations. The resulting distribution functions show good agreement w…

[Phys. Rev. E 114, 015219] Published Fri Jul 24, 2026

Inferring partial crystalline order in liquids from electrical resistivity

Physical Review E (Plasma physics) - Fri, 07/24/2026 - 10:00

Author(s): Nadine Wetta and Jean-Christophe Pain

This work investigates how locally persistent crystal-like ordering in liquids influences the Debye-Waller factor. We have developed a theoretical framework based on liquid-phonon theory which introduces a phonon relaxation time, expressed as the ratio of shear viscosity to infinite-frequency shear …

[Phys. Rev. E 114, 015220] Published Fri Jul 24, 2026

Study on Rayleigh Wave Dispersion and Attenuation in HTI Fractured Porous Media

Geophysical Journal International - Fri, 07/24/2026 - 00:00

SummaryIn near-surface porous media containing aligned fractures and fluids, the propagation of Rayleigh waves is influenced by both fracture geometry and wave-induced fluid flow. These processes introduce frequency-dependent dispersion and azimuthal anisotropy in both phase velocity and attenuation. To investigate these effects, this study applies Chapman-type fracture–pore effective medium theory to describe fluid-saturated fractured media as horizontally transversely isotropic (HTI) media with frequency-dependent complex stiffness. The complex dispersion relation of Rayleigh waves is obtained by combining this model with the Stroh formalism for HTI half-spaces. Numerical results show that Rayleigh-wave phase velocity exhibits clear frequency-dependent dispersion together with azimuthal anisotropy. The fast and slow propagation directions remain consistent with the orientation of the fracture strike. Rayleigh-wave attenuation exhibits a clear relaxation peak within the frequency band associated with wave-induced fluid flow and shows strong azimuthal variation. Parameter analysis further indicates that fracture density primarily controls the strength of azimuthal anisotropy, whereas porosity mainly affects the overall level of dispersion and attenuation. The relaxation time governs the frequency range over which dispersion and attenuation become significant. The combined frequency–azimuth variations of phase velocity and attenuation therefore provide potential constraints for estimating fracture–pore structures in fractured reservoirs using multi-frequency and multi-azimuth Rayleigh-wave observations.

AI unlocks Atlantic circulation insights from 20 years of ocean float data

Phys.org: Earth science - Thu, 07/23/2026 - 23:20

For more than 20 years, about 4,000 autonomous profiling floats have been drifting through the ocean. They form part of the international Argo program (Argo—global array of profiling floats). At regular intervals, they descend to a depth of 2,000 meters (6,600 feet) and, as they rise, measure parameters such as temperature, salinity and pressure. Once they reach the sea surface again, they transmit these data via satellite to the Argo network, which is available to researchers worldwide. Hardly any other observation system has transformed ocean research so profoundly in recent decades.

Global map reveals mining's uneven toll on forests and biodiversity

Phys.org: Earth science - Thu, 07/23/2026 - 21:40

A new study led by Japanese researchers from Tohoku University and the National Institute for Environmental Studies (NIES) reveals that some of the minerals most essential for green technologies may have a significant negative impact on biodiversity. Using remote sensing and machine learning, the scientists produced an unprecedented global map of mined commodities.

Colorado basins supplying 70% of Lake Powell's water face major midcentury shortages

Phys.org: Earth science - Thu, 07/23/2026 - 21:00

If the Colorado River Basin is the lifeblood of the American Southwest, keeping the region's agricultural, ecological and economic systems thriving, Colorado's West Slope River basins could be considered the heart. Together, they contribute about 70% of the water delivered to Lake Powell, the second-largest reservoir in the nation.