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Study finds alpine peaks are greening in the Northeast U.S., Canada

Phys.org: Earth science - Fri, 09/25/2026 - 11:00

In northeastern North America, a stretch of mountains runs 500 miles (800 kilometers) from the Adirondacks in New York to the Gaspé Peninsula in eastern Quebec. Nearly 70 million people live within a day's drive of one of the alpine zones, the areas above the tree line where trees don't grow because of harsh conditions.

Impact of ion-electron collisions on nonlocal ion heat conduction, viscous stress, and diffusion

Physical Review E (Plasma physics) - Fri, 09/25/2026 - 10:00

Author(s): Nicholas Mitchell, David Chapman, and Grigory Kagan

This work demonstrates the impact of ion-electron collisions on ion transport for strongly inhomogeneous plasmas in the nonlocal regime, where collisionality is insufficient to enforce local thermal equilibrium due to sharp gradients. Ion heat conduction and viscous stress in both unmagnetized and m…

[Phys. Rev. E 114, 035215] Published Fri Sep 25, 2026

Comment on “Lightning as a natural source of synchrotron radiation of x-ray and gamma-ray photons”

Physical Review E (Plasma physics) - Fri, 09/25/2026 - 10:00

Author(s): M. L. Shmatov

Petrov [Phys. Rev. E 111, 035205 (2025)] has presented an explanation of some parameters of terrestrial gamma-ray flashes within the framework of his model which is based on the assumptions about the formation of surface plasmon waves and the generation of synchrotron radiation due to the interactio…

[Phys. Rev. E 114, 037201] Published Fri Sep 25, 2026

Off-fault plasticity limits the speed of elongated earthquake ruptures

Geophysical Journal International - Fri, 09/25/2026 - 00:00

SummaryConventional earthquake rupture models in elastic media with scale-independent dissipation predict rupture acceleration up to a limiting speed dictated by seismic wave speeds. However, most earthquakes are inferred to be significantly slower than these theoretical limiting speeds. Previous two-dimensional modeling shows that inelastic deformation of the material surrounding the fault can stabilize rupture propagation at velocities below the limiting speed, owing to scale-dependent dissipation due to the expansion of the off-fault inelastic zone with rupture length. An essential ingredient missing from such models is that large earthquake ruptures become elongated after they saturate the seismogenic width, which prevents a length-dependent growth of the off-fault dissipation zone. Here, we carry out a computational study of elongated ruptures with off-fault plasticity, with a particular focus on steady rupture speeds. We combine a 2.5D (width-averaged) modeling approach and Mohr-Coulomb plasticity to simulate width-limited strike-slip earthquake ruptures propagating in an inelastic medium. We observe steady pulse-like ruptures propagating at speeds below the Rayleigh wave speed. Through a systematic parametric study, we characterize the dependence of the steady rupture speed on the initial fault stress, closeness to plastic failure, and seismogenic zone width. Our simulation results show that off-fault plastic deformation allows the rupture velocity on long faults to saturate at speeds between 6.5 and 99 % of the Rayleigh wave speed, encompassing the common range of speeds of real earthquakes as well as those of tsunami earthquakes. Our results indicate that off-fault plasticity is a viable mechanism for achieving realistic earthquake rupture speeds, even on planar faults with homogeneous stress and strength. The model also provides insights on the factors controlling other earthquake source properties, including pulse width, peak slip velocity, inelastic off-fault deformation and inelastic zone width.

Coastal flooding occurs at predictable times, research reveals

Phys.org: Earth science - Thu, 09/24/2026 - 21:50

Coastal flooding may seem unpredictable, a natural disaster that occurs randomly. But UCF researcher Ivan Haigh has found that recurrent coastal floods occur at highly predictable times.

More than 60 years of beach survey data reveal the extent of shoreline erosion

Phys.org: Earth science - Thu, 09/24/2026 - 21:50

The University of Rhode Island has made one of the world's longest-running beach survey efforts available online through Rhode Island Beach Dynamics Over Decades, a new public website.

Scientists map the changing sounds of the Arctic to strengthen global monitoring

Phys.org: Earth science - Thu, 09/24/2026 - 21:40

As Arctic sea ice retreats, new shipping routes, expanding resource development and growing geopolitical competition are transforming one of the world's least-monitored regions. Scientists at Los Alamos National Laboratory have established one of the first long-term acoustic baselines for the Arctic's underwater soundscape. This work strengthens the detection and interpretation of earthquakes, underwater and nearshore detonations, ship traffic and other events of national security interest.

Scientists find a carbon cycle hiding in desert minerals

Phys.org: Earth science - Thu, 09/24/2026 - 19:40

On the surface, the arid expanses of the Mojave Desert may seem inhospitable and largely removed from the global carbon cycle. But beneath the surface, its mineral-rich soils are running a carbon cycle of their own—one that could account for a surprisingly large share of the planet's annual carbon exchange.