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Charcoal records reveal 'unprecedented' wildfires in tropical peatlands during 20th century

Phys.org: Earth science - Tue, 03/17/2026 - 09:00

A new study reveals an unprecedented increase in wildfires in tropical peatlands during the 20th century. "Unprecedented burning in tropical peatlands during the 20th century compared to the previous two millennia" is published in Global Change Biology.

A milestone voyage for Antarctic science

Phys.org: Earth science - Tue, 03/17/2026 - 02:00

Navigating monolithic icebergs, massive ocean waves and sub-zero snowstorms, CSIRO research vessel (RV) Investigator is a workhorse for Antarctic science. In just over 11 years and spread across seven voyages, the vessel has now spent the equivalent of one full year, or more than 10% of its time, at sea delivering crucial research in Antarctic waters.

Clustering-based AI forecasts river water levels using just a few long records

Phys.org: Earth science - Mon, 03/16/2026 - 23:30

Reliable and scalable water level prediction is crucial in hydrology for effective water resources management, especially when considering challenges owing to climate change, urbanization, improper land use, and high-water demand. It directly impacts the availability and distribution of freshwater in rivers and reservoirs. Therefore, accurate forecasting via early warning systems is a highly useful technique for flood mitigation, agricultural irrigation, ecosystem and environmental sustainability, and numerous other applications.

Satellite mapping reveals recent and large-scale habitat changes across the Southern Ocean's seascapes

Phys.org: Earth science - Mon, 03/16/2026 - 19:50

New research reveals that changes following the recent and dramatic decline in Antarctic sea ice could help a low-nutritional species prosper, with major ramifications for food webs and biogeochemical cycles. The findings are published in the journal Marine Ecology Progress Series.

Coastal ocean chemistry now substantially shaped by humans

Phys.org: Earth science - Mon, 03/16/2026 - 16:00

A global analysis of more than 2,300 seawater samples from more than 20 field studies around the globe indicates that human-made chemicals make up a significant portion of organic matter in coastal oceans. The international study, led by biochemists Jarmo Kalinski and Daniel Petras at the University of California, Riverside, analyzed seawater samples collected over a decade from coastal regions from the Pacific, Atlantic, and Indian oceans.

Managed retreat in Europe more widespread than previously assumed

Phys.org: Earth science - Mon, 03/16/2026 - 14:20

When floods, coastal erosion or sea-level rise threaten settlements or infrastructure, European countries turn to managed retreat more often than previously assumed. Managed retreat refers to the planned, government-supported relocation of people, homes or infrastructure away from areas exposed to flooding and other climate-related hazards. A new German–Dutch study led by Kiel University in collaboration with the Dutch research institute Deltares systematically documents the extent and diversity of such measures in Europe for the first time.

Revealing hidden magmatic underplating in the East China Sea shelf basin using 3D gravity modeling and its tectonic implications

Geophysical Journal International - Mon, 03/16/2026 - 00:00

SummaryLower crustal high-velocity bodies (LCHBs) are key indicators of deep magmatic addition and lithospheric modification at rifted continental margins. Integrating 3D gravity modeling with regional geophysical and geological constraints, we identify a prominent LCHB beneath the Xihu Sag of the East China Sea (ECS) shelf basin. This body is NNE–SSW elongated, ~5–7 km thick, and spatially coincides with major depocenters and fault systems. We propose a two-stage mafic emplacement model linking its formation to the tectonic transition from fore-arc compression to back-arc extension. During the early–mid Cretaceous, compressional subduction of the Paleo-Pacific Plate facilitated arc-related underplating and accumulation of mafic material in the lower crust. In the early Cenozoic, slab rollback and asthenospheric upwelling during back-arc extension renewed melt supply, further thickening the lower crust. The absence of surface volcanism indicates that magmas were largely trapped and crystallized at depth, forming dense mafic cumulates. Present-day low shallow-mantle temperatures and high densities beneath the Xihu Sag suggest that preservation of these cumulates was sustained not solely by mantle thermal conditions, but also by prolonged subsidence, sedimentary insulation, and inherited compressional structures. These results underscore the need to integrate tectonic, thermal, and structural factors to fully understand deep magmatic processes in marginal basins.

Multi-scale Wave-induced Fluid Flow in Partially Saturated Dual-Porosity Media: Theory and Numerical Validation of the Biot-patchy-spherical-squirt Model

Geophysical Journal International - Mon, 03/16/2026 - 00:00

SummaryWe develop a novel comprehensive theoretical framework, the Biot-patchy-spherical-squirt (BIPSSQ) model, for wave propagation in partially saturated dual-porosity media. This model simultaneously incorporates three key fluid flow mechanisms: macroscopic flow (Biot flow or global flow), mesoscopic flow, and microscopic flow (three-dimensional spherical squirt flow). The constitutive relations and fluid pressure expressions for the BIPSSQ model are first derived and then the governing wave equations are established using a Lagrangian approach based on the system’s kinetic energy, potential energy, and dissipation functions. Through plane wave analysis, we obtain the phase velocity and attenuation of the fast P-wave. Numerical examples demonstrate that the BIPSSQ model predicts multiple dispersion transition bands and corresponding attenuation peaks, attributed to two squirt flows and two Biot global flows from two immiscible fluids. Furthermore, the presence of squirt flow significantly suppresses the mesoscopic patchy saturation effect, leading to the disappear of mesoscopic dispersion transition band and attenuation peak. The influences of permeability, saturation, porosity, squirt-flow length and inclusion radius on velocity dispersion and attenuation are also analyzed. Finally, excellent agreement between theoretical predictions and experimental measurements from an Aksu outcrop rock sample (800 kHz), a gas-water-saturated Estaillades limestone (1 kHz), and an oil-brine-saturated Vosgian sandstone (350 kHz), validates the applicability and effectiveness of the BIPSSQ model. Moreover, the BIPSSQ model can degenerate to other theories (i.e. Biot, BISSQ, BR) under certain conditions. Our proposed model provides a unified and robust tool for interpreting wave propagation phenomena in complex, partially saturated reservoir rocks.