In this paper, we review the theoretical studies of the electromagnetic and other non-seismic phenomena accompanying earthquakes. This field of geophysical research is at the interception of several sciences: electrodynamics, solid-state physics, fracture mechanics, seismology, acoustic-gravity waves, magnetohydrodynamics, ionospheric plasma, etc. In order to make physics of these phenomena as transparent

Theories related to the Earth's attenuation effect and earthquake source properties predict a similar spectral falloff of body waves, creating severe trade-off problems when determining these two processes from waveform spectra. Previous efforts attempted to suppress this trade-off by either applying an empirical Green's function or conducting linear inversion with a specially designed event–station

Turbulent entrainment-mixing processes profoundly influence the relationship between radar reflectivity factor and liquid water content (Z-LWC) of cloud droplets. However, quantification of the entrainment-mixing mechanisms based on the Z-LWC relationship is still lacking. To address this gap, 12,218 entrainment-mixing cases are simulated using the Explicit Mixing Parcel Model. We examine the variations

Protection by metal (hydr) oxides is one of the key mechanisms for the long-term stabilization of soil organic carbon (SOC). However, the source and turnover of (metal-) bound organic carbon (OC) in soils are poorly constrained. Here we present the first large-scale study on the 13C and 14C characteristics of bound OC in 15 wetland and upland soil profiles. We find that bound OC has similar δ13C as

The Martian hemispheric dichotomy is delineated by significant differences in elevation and crustal thickness between the Northern Lowlands and Southern Highlands. Yet, its origin remains controversial. Here, we improve the signal-to-noise ratios and determine the locations of the low-frequency marsquakes recorded during the InSight mission. We find a new cluster of marsquakes in Terra Cimmeria, Southern

Poromechanics problems in geotechnical and geological contexts often involve complex formations with numerous boundaries and material interfaces, which significantly complicate numerical analysis and simulation. The traditional finite element method (FEM) encounters substantial challenges in these scenarios because it requires the mesh to conform precisely to each boundary and interface. This requirement

The potential habitability of Jupiter's moon Europa has motivated two missions: NASA's Europa Clipper and ESA's JUpiter ICy moons Explorer (JUICE). Both missions are equipped with ice-penetrating radars which will transmit radio waves into the subsurface, recording reflections from interfaces defined by contrasts in ice shell dielectric properties. Assuming an MgSO4 ocean, we show that salt layers

Due to limited data, the spatial characteristics and connectivity of urban floods in eastern China remain poorly understood. In this study, we established a new data set of urban floods in eastern China during 2010–2020, compiled from multiple sources. Based on this data set, our analysis identified four high-frequency urban flood centers in South, Southeast, Southwest, and North China. Distinct regional

We investigated the compressional and shear velocities, VP and VS, of the HH1-phase by combining the inelastic x-ray scattering and x-ray diffraction experiments. In the pressure range of 64.7–79.6 GPa and at room temperature, the VP and VS were measured to be 9.66–11.05 and 4.9–6.4 km·s⁻1, respectively. We employed a simplified model to quantitatively discuss the sound velocity differences between

Airglow originating from metastable helium He( 2 3 ${2}^{3}$ S) at 1,083 nm has been used to study the upper thermosphere since its discovery in 1959, yielding insights into, for example, solar EUV intensities and thermospheric photoelectron densities. For over 6 decades, these measurements were made passively, relying on solar illumination of the He( 2 3 ${2}^{3}$ S) layer to produce a detectable

The Luzon Strait Deep Overflow (LZDO) transports deep-water masses from the Pacific Ocean (upstream) to the South China Sea (SCS, downstream), playing a vital role in shaping the hydrographic and biogeochemical structure and regulating abyssal circulation within the SCS. Recent studies suggest that the seasonal variability of LZDO transport is primarily wind-driven; however, the specific mechanisms

This paper investigates the day-to-day global tidal variability in the ionosphere/thermosphere system due to fluctuations in the strength of the northern hemisphere stratospheric polar vortex. Using COSMIC-2 (Constellation Observing System for Meteorology, Ionosphere, and Climate-2) Global Ionospheric Specification data, ionospheric tides are derived, with the Northern Annular Mode (NAM) index indicating

The Late Cretaceous obduction of the Semail Ophiolite onto the rifted passive Arabian margin and the Cenozoic collisional tectonics with the final closure of the Neo-Tethys Ocean, are major contributors to the present-day crustal architecture of the northern United Arab Emirates (UAE). We acquired the first 3D grid magnetotelluric observations from 73 stations in the northern UAE in order to image

Pyroclastic density currents (PDCs) present significant hazards due to their high temperatures and dynamic pressures. Accurate estimation of dynamic pressure, vital for assessing potential damage, requires knowledge of the vertical variations of velocity and particle concentration within the PDC, particularly in the first few meters of the flow above the ground. Existing approaches to dynamic pressure

In recent laboratory experiments, varying nucleation locations of accelerating slip with changing nucleation lengths were observed. Spatial variations in effective normal stress, due to the controlling influence on fault strength and fracture energy, play an important role. We quantitatively explain how spatially heterogeneous effective normal stresses affect earthquake nucleation and slip behavior

Sprites have been recorded at ∼100,000 frames per second. One hundred and sixty five essentially vertically propagating streamers, 110 downward and 55 upward, have been selected for analysis. The initial velocity increase is exponential as predicted by theory. Growth rates could be determined for 76 downward and 46 upward propagating streamers, and, in individual streamers, they are independent of

Hurricane Ian rapidly intensified from Category 3 to 5 as it transited the wide West Florida Shelf (WFS). This is ascribed to heating by the anomalously warm shelf waters, despite the water depth being shallow when compared to the thicker, mixed layer areas of the deeper ocean. By examining temperature from long-term moorings, we found that the sea surface and subsurface temperatures exceeded the climatologies

We present the first observations of dust charging and mobilization in a combined vacuum ultraviolet (VUV) and plasma environment. It is experimentally demonstrated that exposing photoemitting dust particles to a low-density plasma enhanced the charge on the particles, accompanied by a significant increase in dust mobilization compared to VUV or plasma exposure alone. Measurements of the dust charge

Detecting old hotspot tracks in a stable continent remains challenging because of the lack of volcano chains on the surface and the fade of thermal anomalies with time. The northeastern American continent moved over the Cape Verde and the Great Meteor hotspots during 300–100 Ma. However, only the latter was confirmed by kimberlites and seismic velocity models. Our new 3D anisotropic model in northeastern

No abstract is available for this article.

No abstract is available for this article.

Earthquake nucleation is a crucial preparation process of the following coseismic rupture propagation. Under the framework of rate-and-state friction (RSF), it was found that the ratios of a$a$ to b$b$ parameters control whether earthquakes nucleate as an expanding crack or with a fixed length prior to the dynamic instability. However, the characteristic weakening distance DR⁢S${D}_{RS}$ controls the

Marine continental shelf sediments with high deposition rates may provide useful archives of rapid geomagnetic secular variation as long as the primary magnetization is not altered substantially by diagenesis. To quantify the effects of sulfate (SO42-) reduction, which is a dominant early diagenetic process in such sediments, on paleomagnetic recording, we analyzed four 6-m long sediment cores from

Geomagnetic field models covering past millennia rely on two main data sources: archaeomagnetic data, that provide snapshots of the geomagnetic field at specific locations, and sediment records, that deliver time series of the geomagnetic field from individual cores. The limited temporal and spatial global coverage with archaeomagnetic data necessitates use of sediment data, especially when models

Diurnal asymmetric warming, a critical feature of climate change, significantly impacts water-carbon exchange in terrestrial ecosystems. This study analyzes the spatiotemporal characteristics and long-term trends of the global diurnal temperature range (DTR) from 1961 to 2022 using ensemble empirical mode decomposition (EEMD). Our results reveal a trend reversal in global averaged DTR around 1988,

Near-inertial waves (NIWs) are essential energy sources for deep diapycnal mixing. However, the mechanisms for generating deep and abyssal NIWs are largely unknown. Here, using 3 year full-depth mooring data at 130°E/15°N, we demonstrate that downward propagating tropical cyclone (TC)-induced NIWs and parametric subharmonic instability (PSI) can contribute to the intensification of near-inertial kinetic

To understand the dislocation creep behavior of clinopyroxene in the upper mantle, hot-pressed diopside aggregates without predrying treatment were triaxially deformed under water-unsaturated conditions at a confining pressure of 300 MPa, temperatures of 1323–1523 K, and strain rates of 10−6–10−4 s−1, using a Paterson gas-medium apparatus. Fourier transform infrared measurements of the water contents

The seismic potential of faults depends on the local mineralogy and can change upon mineral reactions. We conducted friction experiments on serpentinite, carbonate and carbonated serpentinite fault gouges at temperatures from 400°C to 630°C, under 100 MPa effective normal stress and fluid saturated conditions. Pure serpentinite fault gouges exhibited unstable slip with significant strain-hardening

Debate continues over the reducing mechanisms for the formation of unconformity-related uranium (URU) deposits. This paper evaluates, for the first time, the potential of iron-rich chlorite as a reductant for uranium mineralization using reactive fluid flow modeling method. Our results confirm that Fe2+, released from the breakdown of iron-rich chlorite, can reduce aqueous hexavalent uranium to precipitate

Extratropical disturbances are known to impact the genesis and intensification of Mixed Rossby-Gravity waves (MRGW) in the Western Hemisphere (WH). The study provides observational evidence supporting the wave resonance (WR) theory which attempts to explain the intensification of MRGW by extratropical forcing. Wavenumber-frequency cospectral analysis and a bulk measure of growth of MRGW estimated using

Reanalysis products support our understanding of how the precipitation phase influences hydrology across scales. However, a lack of validation data hinders the evaluation of a reanalysis-estimated precipitation phase. In this study, we used a novel dataset from the Mountain Rain or Snow (MRoS) citizen science project to compare 39,680 MRoS observations from January 2020 to July 2023 across the conterminous

We applied state-of-the-art seismic processing and imaging techniques to crustal-scale seismic reflection data from the BELCORP/DEKORP87 lines 1A and 1B. The aim of the presented work was to identify structural evidence in the Earth's crust and upper mantle related to the ongoing magmatic activity in the Quaternary West Eifel Volcanic Field (WEVF) in Central Europe where ca. 70 eruptions happened since

Uranus remains one of the most unexplored planets in our solar system, featuring a distinctive magnetic field structure first observed by NASA's Voyager 2 mission almost 40 years ago. Uranus is particularly notable for its pronounced magnetic field asymmetry, a characteristic unique to the icy giants. Here we show that, in the region where Voyager 2 did not pass (<4RU${< } 4\,{R}_{U}$), the asymmetric

Changes in Mediterranean circulation patterns due to global warming may have strong socio-economic and environmental impacts. We analyze the future evolution of the Mediterranean surface circulation under different levels of global warming by using 28 multi-decadal simulations from a set of fully coupled and high-resolution regional climate models of the Med-CORDEX multi-model initiative. There is

We investigated, for the first time, the impact of the disappearing solar wind (DSW) event [26–28 December 2022] on the deep nightside ionospheric species using MAVEN data sets. An enhanced plasma density has been observed in the Martian nightside ionosphere during extreme low solar wind density and pressure periods. At a given altitude, the electron density surged by ∼2.5 times, while for ions (NO+

As a part of the Tropical Cyclone Rapid Intensification (TCRI) project, we investigated thermodynamic conditions necessary for cyclone intensification. While high sea surface temperature and low tropospheric wind shear are well known environmental factors contributing to storm intensification, they are not sufficient to predict intensification and rapid intensification in particular. To explore thermodynamic

Europe is expected to experience major climatic shifts during the 21st century but the impact on agricultural productivity from such changes is uncertain. Here, we combine proxy, instrumental, and model data to assess interannual to multi-centennial changes in central European agroclimate over the past 2,000 years and projections into the near future. Whereas early 21st century conditions are rare

Solar wind drives magnetospheric dynamics through coupling with the geospace system at the magnetopause. While upstream fluctuations correlate with geomagnetic activity, their impact on the magnetopause energy transfer is an open question. In this study, we examine three-dimensional global magnetospheric simulations using the Geospace configuration of the Space Weather Modeling Framework. We examine

The relative contribution of adiabatic and non-adiabatic processes to electron heating across collisionless shocks remains an open question. We analyze the evolution of suprathermal electrons across 310 quasi-perpendicular shocks with Alfvénic Mach numbers in the normal-incidence frame (MA−N⁢I⁢F)$\left({M}_{A-NIF}\right)$ ranging from 1.7 to 48, using in situ measurements of Earth's bow shock by the

Interdecadal changes in the relationship between East Asian Summer Monsoon Precipitation (EASMP) and the concurrent El Niño-Southern Oscillation (ENSO) vary across subregions, making it challenging to holistically understand these variations and the underlying mechanisms. To address this issue, we apply the moving correlation Empirical Orthogonal Function (MC-EOF) between EASMP and ENSO, identifying

Nine-years of mesospheric wind measurements, from two meteor radars at 52°N latitude, were analyzed to study planetary waves (PWs) and tides through estimating their zonal wavenumbers. The analysis reveals that multi-day oscillations are predominantly driven by PW normal modes (NMs), which exhibit distinct seasonal variations and statistical association with Sudden Stratospheric Warming events. Specifically

The interannual-to-decadal variability of sea surface temperature and height in the North Atlantic exhibits a tripolar pattern. Here, we explore the spatiotemporal structure, including the vertical, of the North Atlantic tripole using observations and reanalysis data in 1993–2021. For the first time, we demonstrate that the tripole's vertical structure across the Mid-Atlantic Bight continental shelf

There is a pressing need for global monitoring of snow water equivalent (SWE) at high spatiotemporal resolution, and L-band (1–2 GHz) interferometric synthetic aperture radar (InSAR) holds promise. However, the technique has not seen extensive evaluation in forests. We evaluated this technique across varying forest canopy conditions using eight InSAR pairs collected at the Fraser Experimental Forest

Ionospheric topside O+${O}^{+}$ diffusive flux is derived using Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation data, to investigate its global distribution and also its role in winter nighttime enhancement (WNE) of electron density. The flux of the winter hemisphere maintains downward throughout the night. It is much larger between 30°$30{}^{\circ}$

The Southern Puna plateau in the central Andes has a complicated tectonic history that includes episodes of distributed shortening and extension, lithospheric delamination, uplift and Quaternary backarc volcanism. In this study, the upper crustal structure and present-day deformation in this area is investigated using a new regional earthquake catalog derived with a deep-learning-based phase picker

The lack of accurate information on the spatiotemporal variations of snow water equivalent (SWE) in mountain catchments remains a key problem in snow hydrology and water resources management. This is partly because there is no sensor to measure SWE beyond local scale. At Mt. Zugspitze, Germany, a superconducting gravimeter senses the gravity effect of the seasonal snow, reflecting the temporal evolution

East Antarctica has experienced significant positive temperature anomalies during winter 2018, with Zhongshan (ZS) station recording its highest winter average temperature since 2008 and fourth highest since its establishment in 1989. This study employs observational data and ERA5 reanalysis to diagnose the phenomenon, revealing that temperature anomalies at 300 hPa are mainly driven by advection and

Despite historically low seismic activity on the Maidan Fault (MDF), the sudden Mw 7.0 Wushi earthquake in early 2024 underscores the urgent need to assess the seismic risk on this fault. This study utilizes Global Navigation Satellite System and Interferometric Synthetic Aperture Radar data to image the spatial distribution of interseismic coupling before the Wushi event along the MDF. The four asperities

The Nankai subduction zone presents significant seismic and tsunami risks, given its historical earthquakes exceeding magnitude 8 and the expectations of similar future events. Slow earthquakes, common at the shallow and deep plate interface, result from different frictional properties linked to interplate slip deficit accumulation. This study estimates slip deficit rates at the Nankai subduction zone

Mineral chemistry records the pressure and temperature conditions of lithospheric processes. Active tectonic margins, however, are subjected to non-hydrostatic stresses wherein stress magnitudes vary directionally, and the impact of non-hydrostatic stress on mineral chemistry is uncertain. The work of materials scientists F. Larché and J. Cahn provides a framework for quantifying how stress affects

Semi-brittle and plastic deformation behaviors of mafic granulite are significant for evaluating characteristics of ductile zones in the lower crust region and the rheological strength of the lower crust. Axial compression experiments were carried out in this study with natural mafic granulite collected from the North China Craton, using a gas medium apparatus at 950–1,150°C and 300 MPa with strain

Convective cloud processes are sensitive to environmental conditions that vary on scales smaller than reanalysis data sets (sub-reanalysis scales). Convective environment variability within areas representative of reanalysis data sets is quantified using large-domain, high-resolution (∆x = 100 m) simulations of convective cloud systems throughout the tropics and subtropics. Even after removing locations

Seismoelectric phenomena, caused by electrokinetic coupling between seismic and electromagnetic fields, have attracted significant interest in geological reservoir characterization for their sensitivity to pore-fluid contrasts. Consequently, most studies have focused on seismic-to-electromagnetic conversions at fluid/poroelastic and poroelastic/poroelastic interfaces. However, when investigating permeable

Understanding the relationships between internal variability and forced climate feedbacks is key for using observations to constrain future climate change. Here we probe and interpret the differences in these relationships between the climate change projections provided by the CMIP5 and CMIP6 experiment ensembles. We find that internal variability feedbacks better predict forced feedbacks in CMIP6

Although fluctuations in ice sheet surface mass balance lead to seasonal and interannual elevation changes, it is unclear if they are resolved differently by radar and laser satellite altimeters. We compare methods of computing elevation change from CryoSat-2 and ICESat-2 over the Greenland Ice Sheet to assess their consistency and to quantify recent change. Solutions exist such that interannual trends

This study presents a novel approach for conducting all-day retrieval of cloud macro-physical properties (single-layer cloud phase, cloud top height, and cloud base height for optical thickness less than 10) using the Advanced Geostationary Radiation Imager (AGRI) and the Geostationary Interferometric Infrared Sounder (GIIRS) onboard the geostationary meteorological satellite Fengyun-4A based on machine

Leveraging the unique perspective enabled by Global-scale Observations of the Limb and Disk, we examined the characteristics of equinox transitions in the thermospheric column integrated ratio of atomic oxygen to molecular nitrogen (O/N2) in the Northern Hemisphere. We found that the timing of the O/N2 equinox transition from winter to summer or vice versa exhibits a progression with latitude, particularly

Biomass burning (BB) can produce ice nucleating particles (INPs) and influence cloud ice formation and climate effects, but the distribution and budget of BB-induced INPs are not well understood. This study quantified INPs from BB at −17°C to −30°C and explored their spatiotemporal distributions. The results indicate that the INPs of BB aerosol were 5.42 × 1021 in 2019, approximately two orders of

To estimate a non-uniform effective elastic thickness (Te) of lithosphere across Korean Peninsula and the Surrounding Seas (KPSS), we employ gravitational coherence analysis between gravity anomalies and topography/bathymetry data in the Fourier domain. Exploring crustal flexure and effective elastic thickness variations can offer insights into flexural strength, and evolutionary mechanics of the lithosphere