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A new systematic review has revealed serious shortcomings in the evaluation of cyclone risk in Australia and worldwide. The research, which analyzed 94 studies on cyclone risk, warns that existing approaches may be failing to provide a full picture of the dangers communities face.

ARPENN: An Improved Deep Convolutional Neural Network for Bathymetry Inversion with Integrated Physical Constraints

Geophysical Journal International - Sat, 03/08/2025 - 00:00

SummaryWith advancements in deep learning (DL) technology, many scholars have applied it to bathymetry inversion, gradually revealing its potential. However, most current studies focus primarily on data-driven approaches, using various gravity data combinations for bathymetry inversion, without fully exploring the models′ capabilities or understanding the relationship between gravity and bathymetry. This study proposes a novel Attention Residual Physical Enhanced Neural Network (ARPENN), an architecture integrating attention mechanisms, residual modules, and physical constraints to help the model better understand the physical context, which enhances the utilization of shipborne data and effectively addresses the divergence issues faced by traditional algorithms in areas without shipborne measurements. The experimental results demonstrate that ARPENN achieves a root mean square (RMS) of 77.37 meters based on single-beam testing, outperforming the CNN method by 17.21 per cent and the classical Smith and Sandwell (SAS) method by 40.11 per cent. In complex regions, multi-beam evaluation shows ARPENN improves over SAS by 14.4 per cent. Further analysis reveals that the residual modules and physical constraints are identified as critical for improving accuracy, while attention mechanisms enhance robustness. ARPENN effectively reduces depth anomalies compared to GGM and SASA, achieving a reduction in anomaly rates by approximately 8.00 per cent and bringing them closer to zero. In evaluations using SIO_V25.1 as a reference, ARPENN demonstrates better stability and consistency. The ARPENN model offers promising potential for advancing global bathymetry prediction, particularly in improving depth estimation in areas surrounding continental margins.

Earth's hidden carbon recyclers: Sulfur bacteria team up to break down organic substances in the seabed

Phys.org: Earth science - Fri, 03/07/2025 - 19:00

Sulfate-reducing bacteria break down a large proportion of the organic carbon in the oxygen-free zones of Earth, and in the seabed in particular. Among these important microbes, the Desulfobacteraceae family of bacteria stands out because its members are able to break down a wide variety of compounds—including some that are poorly degradable—to their end product, carbon dioxide (CO2).

Ditches and canals are a big, yet overlooked, source of greenhouse gas emissions

Phys.org: Earth science - Fri, 03/07/2025 - 16:30

It's a cold winter morning in the bleak and bare arable fields of the East Anglian fens. At the edge of a field, a scientist dips a long pole into a ditch. So, what is a climate researcher doing here?

Cyclone Alfred is traumatizing people who've lived through other disasters

Phys.org: Earth science - Fri, 03/07/2025 - 16:13

In 2011, as Cyclone Yasi approached the Queensland coast, I sat in my home in the tropical far north of the state and worried what the future would hold. Would my family be OK? Would our home be destroyed? Would my workplace be damaged and my job uncertain? Would my community be devastated?

How cyclones rip apart houses—and how to boost the chance your home stays standing

Phys.org: Earth science - Fri, 03/07/2025 - 15:50

People in southeast Queensland and northern NSW have spent days racing to prepare their homes ahead of Tropical Cyclone Alfred, now expected to make landfall over several hours on Saturday.

Image: Kachemak Bay's stony waters

Phys.org: Earth science - Fri, 03/07/2025 - 14:45

The OLI (Operational Land Imager) on Landsat 8 captured an image of Kachemak Bay's turbid, cloudy waters on September 20, 2024. This cloudiness comes from glacial flour: bits of pulverized rock ground down by glaciers that has the consistency of flour.

Airborne microplastics: Where do they come from, where do they go?

Phys.org: Earth science - Fri, 03/07/2025 - 13:33

How tiny plastic particles enter the atmosphere is an important question, as airborne microplastics are a potential health threat. Using a global chemical transport model, researchers have provided evidence that, contrary to previous claims, the ocean is not a major source of microplastics to the atmosphere, but a significant sink.

Shapiro steps observed in a two-dimensional Yukawa solid modulated by a one-dimensional vibrational periodic substrate

Physical Review E (Plasma physics) - Fri, 03/07/2025 - 10:00

Author(s): Zhaoye Wang, Nichen Yu, C. Reichhardt, C. J. O. Reichhardt, Ao Xu, Xin Chen, and Yan Feng

Depinning dynamics of a two-dimensional (2D) solid dusty plasma modulated by a one-dimensional (1D) vibrational periodic substrate are investigated using Langevin dynamical simulations. As the uniform driving force increases gradually, from the overall drift velocity varying with the driving force, …

[Phys. Rev. E 111, 035202] Published Fri Mar 07, 2025

High-energy space particles may play a role in initiating lightning flashes

Phys.org: Earth science - Fri, 03/07/2025 - 09:29

Researchers from Los Alamos National Laboratory have discovered that cosmic-ray showers seem to play a pivotal role in triggering lightning flashes. The research is published in the journal JGR Atmospheres.

Analysis of Saturation Effects of Distributed Acoustic Sensing and Detection on Signal Clipping for Strong Motions

Geophysical Journal International - Fri, 03/07/2025 - 00:00

SummaryDistributed Acoustic Sensing (DAS) systems are increasingly used for earthquake monitoring due to their cost-effectiveness and high spatial resolution. However, signals exceeding the dynamic range in DAS systems lead to signal clipping and data loss during strong ground motion and near-fault observations. In this study, we investigated the saturation effects of DAS signal clipping using two collocated DAS arrays with a looped setup in Hualien City, drawing on seismic data from the 2022 MW 7.06 Taitung earthquake sequence. The two DAS arrays, connected to different interrogators, simultaneously recorded the earthquake signals and exhibited different dynamic ranges, allowing for direct comparisons of clipped and unclipped signals. Our results indicate that the primary factors contributing to signal clipping in DAS can be categorized as (1) strong ground motion induced by earthquake magnitude and cable installations and (2) the limited dynamic range of the interrogator. Furthermore, our analysis reveals that signal clipping leads to an amplitude increase across all frequencies in the spectra, resembling the addition of a white-noise-like signal that contaminates the waveform spectra. To address this issue, we develop a frequency-based detection approach using spectral coherence estimation on collocated channels to identify clipped signals. Our findings demonstrate that coherencegrams can be employed to detect clipped signals to ensure the reliability of DAS data during strong ground motion and enhance applications that rely on near-real-time high-quality data, such as earthquake early warning systems.

Whole-mantle tomography beneath eastern Mediterranean and adjacent regions

Geophysical Journal International - Fri, 03/07/2025 - 00:00

SummaryThe Mediterranean and its surrounding regions are characterized by strong interactions of the Eurasian, African and Arabian Plates, as well as several microplates, resulting in significant seismic and volcanic activities. In addition, this region has a complex history of plate movements, leading to the formation of distinct orogenies such as the Alps, Apennines, and Carpathians, as well as a complex distribution of subducted slabs in the mantle. Intermediate-depth earthquakes actively occur in the subducting Vrancea slab beneath Romania. Furthermore, volcanic activity in the Caucasus and Arabian Peninsula may be stimulated by mantle plumes. To better understand the complex tectonics and seismic and volcanic activities, we need to study the detailed 3-D structure of the crust and mantle beneath this region. However, previous studies did not thoroughly investigate the 3-D structure of the whole mantle, particularly the lower mantle. Here we apply the updated global tomography method to reveal the 3-D P-wave velocity (${V}_P$) structure of the whole mantle beneath this region. We use ∼7 million P, pP, PP, PcP, and Pdiff wave arrival times of 21,629 earthquakes recorded at 14,283 seismograph stations worldwide. The resulting ${V}_P$ tomography clearly shows stagnation of the subducted African and Tethys slabs above the 660-km discontinuity, although a portion of the slab penetrates the discontinuity and sinks into the lower mantle. A big mantle wedge (BMW) has formed above the stagnant slab, which may affect the surface topography and seismic activity such as the Vrancea intermediate-depth earthquakes. A window appears between the subducting Hellenic and Cyprus slabs. Given the development of subslab hot mantle upwelling (SHMU) beneath this region, an extensive volcanic eruption in the Aegean Sea area might be powered by a mixture of island arc magma and SHMU through the slab window. Intraplate volcanoes in the Arabian Peninsula and Caucasus may be fed by hot mantle plumes rising from the core-mantle boundary.