Feed aggregator

The Atlantic Meridional Overturning Circulation (AMOC)—a major transporter of heat to the north Atlantic and northwestern Europe—is unlikely to collapse this century, according to new research.

New findings date Los Chocoyos supereruption to 79,500 years ago, and show Earth bounced back within decades

Phys.org: Earth science - Sat, 03/01/2025 - 16:10

An international team of Earth and life scientists, hydrologists, chemists, and physicists, has found evidence showing that the Los Chocoyos supereruption occurred approximately 79,500 years ago and that the planet bounced back from its chilling effects within decades.

Design and performance of the Space Environment In-Situ Suite on the FY-4B Satellite

Recent articles in Advances in Space Research - Fri, 02/28/2025 - 19:10

Publication date: Available online 16 February 2025

Source: Advances in Space Research

Author(s): Jinsong Wang, Xin Zhang, Yaohai Dong, Xianguo Zhang, Yueqiang Sun, Weiguo Zong, Anqin Chen, Liguo Zhang, Xiaoxin Zhang

Scientists reveal evolutionary history of continent-sized regions in the deep mantle

Phys.org: Earth science - Fri, 02/28/2025 - 16:48

A new study has revealed that two continent-sized regions in Earth's deep mantle have distinctive histories and resulting chemical composition, in contrast to the common assumption that they are the same. The findings are available to read in the journal Scientific Reports. The study was led by researchers at Cardiff University, the University of Oxford, the University of Bristol, and the University of Michigan.

Findings reveal an important link to Northern Hemisphere extreme temperatures

Phys.org: Earth science - Fri, 02/28/2025 - 14:23

Heat waves have gotten hotter in the Northern Hemisphere in recent decades. Home to about 90% of the world's population, with the largest fraction living in the mid-latitudes, more frequent and more severe heat waves and droughts have occurred in the Northern Hemisphere—in Europe in 2003, 2010 and 2019, in North America during 2018 and 2021, and in eastern China in 2013 and 2022.

Sensitivity of the dynamic-shell target to laser drive nonuniformities

Physical Review E (Plasma physics) - Fri, 02/28/2025 - 10:00

Author(s): William Trickey, T. J. B. Collins, I. V. Igumenshchev, V. N. Goncharov, and A. Shvydky

The dynamic-shell concept for inertial confinement fusion (ICF) uses an initially homogeneous target and a carefully shaped laser pulse to form a shell and implode it. The laser pulse consists of a series of pickets that drive shocks into the target. The first few shocks converge inwards and rebound…

[Phys. Rev. E 111, 025210] Published Fri Feb 28, 2025

Energy-momentum-conserving stochastic differential equations and algorithms for the nonlinear Landau-Fokker-Planck equation

Physical Review E (Plasma physics) - Fri, 02/28/2025 - 10:00

Author(s): Yichen Fu, Justin R. Angus, Hong Qin, and Vasily I. Geyko

Coulomb collision is a fundamental diffusion process in plasmas that can be described by the Landau-Fokker-Planck (LFP) equation or the stochastic differential equation (SDE). While energy and momentum are conserved exactly in the LFP equation, they are conserved only on average by the conventional …

[Phys. Rev. E 111, 025211] Published Fri Feb 28, 2025

Dynamic weakening in sandstone-derived fault gouges during simulated small-magnitude earthquakes under variable loading and environmental conditions

Geophysical Journal International - Fri, 02/28/2025 - 00:00

SummaryFaults exhibit dynamic weakening during large displacements (>1 m) at seismic slip velocities (>0.1 m/s), but the role of this weakening in small-displacement induced earthquakes (M 3–4), such as those in the Groningen Gas Field (the Netherlands), remains unclear. We conducted seismic slip-pulse experiments on Slochteren sandstone gouges (SSG) using a rotary-shear apparatus to investigate their dynamic behavior. Pre-sheared gouge layers, confined between ∼1.5 mm thick sandstone host blocks, were subjected to slip pulses at initial effective normal stresses of 4.9–16.6 MPa and pore fluid pressures of 0.1 and 1 MPa under undrained conditions. Slip pulses reached peak velocities of 1.8 m/s, accelerations up to 42 m/s², and displacements of 7.5–15 cm, using either dry Argon or water as pore fluid at ambient temperatures. Water-saturated gouges showed rapid weakening from a peak friction of ∼0.7 to ∼0.3, with early dilatancy followed by slower ongoing dilation. In contrast, Argon-filled samples exhibited only subtle weakening. Our findings confirm that water-saturated SSG weakens substantially during slip, with minimal dependence on normal stress, slip acceleration, or displacement, while dry samples do not. Microstructural analysis indicates no systematic relationship between PSZ width and frictional work or power input densities, suggesting that wear or heat production alone does not govern PSZ growth. Instead, thermal pore fluid pressurization, potentially involving water phase transitions at asperity scales, may drive weakening in short-displacement, induced seismic events.

New insights on cyclone wake recovery can help to advance predictive models for extreme weather events

Phys.org: Earth science - Thu, 02/27/2025 - 21:27

A study led by UMass Dartmouth School for Marine Science & Technology (SMAST) Ph.D. student Siddhant Kerhalkar sheds new light on the recovery of ocean thermal structures following cyclone passage—an area of oceanography that has remained largely unexplored due to the scarcity of direct shipboard observations. This research enhances our understanding of how the ocean recovers after cyclones, which is essential for improving climate models and predicting extreme weather events.

Downscaling method creates high-resolution soil moisture mapping in rough terrain

Phys.org: Earth science - Thu, 02/27/2025 - 20:25

A new downscaling method has been developed to generate high-resolution surface soil moisture (SSM) data for mountainous regions. By integrating land surface temperature (LST) and vegetation index (VI) data, this innovative technique enhances the spatial resolution of coarse satellite-based SSM products, correcting for topographic effects and providing accurate, seamless SSM maps. This advancement is poised to revolutionize hydrological studies, drought monitoring, and climate change research.

Scientists match Earth's ice age cycles with orbital shifts

Phys.org: Earth science - Thu, 02/27/2025 - 20:11

Beginning around 2.5 million years ago, Earth entered an era marked by successive ice ages and interglacial periods, emerging from the last glaciation around 11,700 years ago. A new analysis suggests the onset of the next ice age could be expected in 10,000 years' time.

Machine learning approach simulates geochemical element concentrations in rocks and stream sediments

Phys.org: Earth science - Thu, 02/27/2025 - 19:11

Researchers led by Prof. Li Nuo from the Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences have developed a method to simulate the concentrations of unmeasured geochemical elements in rock and stream sediment samples.

Weak rocks and melting ice sheet explain rapid ground uplift in Southeast Greenland

Phys.org: Earth science - Thu, 02/27/2025 - 16:05

The coastline of Southeast Greenland is uplifting more rapidly than other parts of the island. This is caused by weak rocks beneath this part of Greenland, combined with the melting of the ice sheet, according to researchers.

Stark effect at high electric fields and Stark ion broadening widths and shifts for different microfield distributions at quasistatic approximation in atomic oxygen spectra

Physical Review E (Plasma physics) - Thu, 02/27/2025 - 10:00

Author(s): S. Werbowy, B. Pranszke, and L. Windholz

Studies of the static Stark effect are reported for the multiplets at 615.8, 645.6, 777.6, 822.4, 844.9, and 926.5 nm (vacuum wavelengths) of atomic oxygen, which are important for various applications. From the Stark patterns recorded at very high electric fields up to 780 kV/cm, we have determined…

[Phys. Rev. E 111, 025209] Published Thu Feb 27, 2025