The vertical structure of internal tide dissipation rate ϵ is essential to the parameterization of the internal tide‐induced mixing, yet its diversity has always been oversimplified in ocean circulation models. Based on a high‐vertical‐resolution (10 m) simulation around the exits of the Indonesian throughflow, the diversity in ϵ profiles near both the bottom and the thermocline was investigated by

Dangerous turbulences were observed in the eyewall of category 5 Hurricane Hugo (1989) and the surface pressure associated with the turbulence was 8 hPa lower than the mean pressure in the eye. In this study, it is demonstrated that small scale, negative pressure perturbations in the tropical cyclone eyewall are associated with the tornado‐scale vortex (TSV) simulated with the large‐eddy simulation

The E‐region equatorial electric field (EEF) modulates distributions in the ionosphere at equatorial and low latitudes via the fountain effect. Using Swarm data during the daytime and geomagnetically quiet periods (Kp ≤ 3), we perform a detailed analysis of the main wave sources of the longitudinal structures of the EEF (LSEEF) in different seasons by fitting the LSEEF with longitudinal wavenumber

We determined the single‐crystal elasticity of Fe3+‐bearing grossular using Brillouin scattering up to 22 GPa and 1,000 K. Using the obtained results, we modeled mantle velocity profiles to investigate the origin of low‐velocity zones (LVZs) in the bottom 100 km of the mantle transition zone. Our modeling revealed that although a water‐saturated transition zone could be seismically detected as the

We simulated tsunami propagation for several scenario slip distributions for the 1938 MW 8.3 earthquake along the Alaska Peninsula and compared these to the observed records at Unalaska/Dutch Harbor and Sitka. The Sitka record is sensitive to the depth of slip but not the along‐strike location and is fit best by slip at shallow depth. The Unalaska record is sensitive mainly to the along‐strike location

Understanding the origin of volatiles and identifying opaque phases on the surface of Mercury are important tasks to be completed to understand the planet's building blocks and early evolution. Pyroclastic deposits, typically featuring higher and steeper reflectance spectra than the global average, are a bridge connecting the two tasks. We report the first discovery of dark pyroclastic deposits on

Changes in the permeability of a fault zone are dependent upon the frequency of seismic waves, and is an important phenomenon whose mechanisms have not be completely elucidated to date. In this study, the tidal response of water level in well Chuan06 was considered as an indicator of the permeability of the fault zone, and the sensitivity of permeability changes to earthquakes with different epicentral

The Yucatan Peninsula is composed of highly porous, karstified limestone, resulting in scarce surface water bodies. Portions of the peninsula have fracture zones throughout the subsurface. We present water level measurements from four inland locations, previously assumed to be hydrologically isolated from the regional aquifer, or at most leaky with a weak connection. At all locations, tidal oscillations

Surface‐wave inversion is a non‐linear and ill‐conditioned problem usually solved through deterministic or global optimization approaches. Here, we present an alternative method based on machine learning. Under the assumption of a local 1D model, we train a residual neural network to predict the non‐linear mapping between the full dispersion image and the model space, parameterized in terms of shear

Abstract The micro heterogeneities have a significant effect on the mechanical behaviour and failure mode of brittle rocks. In order to study the influence of microstructure and micro-mechanical properties on rock fracturing under blast loadings, a hybrid LS-DYNA and UDEC grain-based discrete element method (UDEC-GBM) is developed in this study. The LS-DYNA code is used to simulate the explosive detonation

Abstract Rock brittleness is an essential factor affecting underground engineering disasters and energy extraction. A large number of cracks are generated during rock destruction, and many acoustic emission (AE) signals are accompanied. The propagation speed and modes of cracks in different brittle rocks differ during failure, and their AE signals also show differing characteristics. In this study

We investigated the seismic velocity structure of the Hikurangi margin in New Zealand to uncover the physical features of the subduction zone and explore the relationships between microearthquake seismicity, seismic velocity structure, and slow slip events. Using local earthquake tomography with data collected from both temporary ocean bottom seismometers and on‐land permanent seismic stations, we

The spatiotemporal patterns of injection‐induced seismicity (IIS) are commonly interpreted with the concept of a triggering front, which propagates in a diffusion‐like manner with an associated diffusivity parameter. Here, we refer to this diffusivity as the “seismic diffusivity”. Several previous studies implicitly assume that seismic diffusivity is equivalent to the effective hydraulic diffusivity

The development of Digital rock physics relies on the availability of high‐quality 3D digital rock images, which can be directly obtained with X‐ray micro‐Computed Tomography (μCT). However, X‐ray μCT is hampered by its high expenses, small sample size (several millimeters in diameter) and low resolution (in micron scale). Although Scanning Electron Microscope (SEM) provides higher resolution on larger

A coupled approach of fluid flow and geomechanics is proposed in this paper to quantitatively understand the hydraulic fracturing‐induced poroelastic effects that activate pre‐existing faults and trigger earthquake swarms near Crooked Lake, Alberta. The 3D poroelastic simulation of the seismogenic fault zone is then conducted to characterize the pressure diffusion and stress perturbation that led to

The southern Granite‐Rhyolite province contains a comprehensive record of lithospheric evolution in North America. During the last decade, increased seismicity along with improved seismic monitoring in Oklahoma provided a rich catalog of local earthquakes. The source‐receiver geometry of this dataset is well posed to illuminate the middle and lower crust through long‐offset recordings of the Pg phase

In Gravity Recovery and Climate Experiment (GRACE) Follow‐on (GRACE‐FO) mission, similar to its predecessor GRACE, the twin satellites are equipped with three‐axis accelerometers, measuring the non‐gravitational forces. After 1 month in orbit, during the in‐orbit‐checkout phase, the noise on GRACE‐D accelerometer measurements elevated and resulted in systematical degradation of the data. For this reason

Repeating earthquakes repeatedly rupture the same seismic asperity and are strongly linked to aseismic slip. Here, we study the repeating aftershocks of the April 16, 2016 MW 7.8 Pedernales earthquake in Ecuador, which generated a large amount of afterslip. Using temporary and permanent stations, we correlate waveforms from a one‐year catalog of aftershocks. We sort events with a minimum correlation

Microbial degradation of DOM contributes to the formation and preservation of oxygen minimum zones (OMZs) in the ocean, but information on the spatial distribution and molecular composition of DOM in OMZ regions is scarce. We quantified molecular components of DOM i.e. dissolved amino acids (DAA) and dissolved combined carbohydrates (DCCHO), in the upwelling region off Peru. We found the highest concentrations

Ice‐off dates on lakes are some of the longest phenological records in the field of ecology, and some of the best evidence of long‐term climatic change. However, there has been little investigation as to whether the date of ice‐off on a lake impacts spring and summer ecosystem dynamics. Here, I analyzed 274 years of long‐term data from eight north temperate lakes in two climate zones to address whether

Elevated reactive nitrogen (N) input could modify soil N transformations, regulating ecosystem functions such as soil N retention and loss. Although multiple hypotheses advocate nonlinear variations in soil N transformations with continuous N input, there still lacks empirical evidences for the responses of soil N transformations to multiple N additions. Here, based on a manipulative N addition experiment

In the last decade, much work has been done to better understand methane (CH4) emissions from the oil and gas (O&G) industry in the United States. Ethane (C2H6), a gas that is co‐emitted with thermogenic sources of CH4, is emitted in the US predominantly by the O&G sector. In this study, we perform an inverse analysis on 200 hours of atmospheric boundary layer C2H6 measurements to estimate C2H6 emissions

Aerosols associated with biomass burning sources in Southern Africa were the focus during the LASIC, CLARIFY, and ORACLES field intensives across the South Tropical Atlantic in August and September of 2017. During this period, we launched twenty ozonesondes to produce a high temporal resolution dataset to complement the once per week regular ozonesondes to investigate episodes of elevated O3 mixing

Reconstructions of paleoatmospheric H2 using polar firn air and ice cores would lead to a better understanding of the H2 biogeochemical cycle and how it is influenced by climate change and human activity. In this study, the permeability, diffusivity, and solubility of H2 are determined experimentally in ice Ih at temperatures relevant to polar ice sheets (199‐253 K). The experimental data are used

Gravity wave (GW) activities in the upper mesosphere (80–100 km) and their potential sources are investigated using meteor radar observations at King Sejong Station, Antarctica (KSS; 62.22°S, 58.78°W) during recent 14 years (2007–2020). GW activities are estimated by horizontal wind variances of small‐scale GWs (periods < 2 h, horizontal wavelength < 400 km, or vertical wavelength < 3–5 km). The wind

There has been growing interest in the potential of short‐lived climate forcer (SLCF) mitigation to reduce near‐term global warming. Black carbon (BC), organic carbon (OC) and sulfur dioxide (SO2) are SLCF which change the Earth’s radiative balance directly by affecting radiation, and indirectly by altering cloud properties. We used the ECHAM‐HAMMOZ aerosol‐climate model to study the radiative forcings

Macrophysical and microphysical features of clouds and precipitation at coastal [20m above Mean Sea Level (MSL)] and high‐altitude cloud physics observatory (HACPO; 1820m above MSL) sites on the windward side of Western Ghats are examined using ground (Ceilometer and Disdrometer) and satellite‐based observations for the years 2017 and 2018 during the pre‐monsoon and post‐monsoon seasons. Low‐ and high‐level

Several single‐year‐long (2017) simulations with different configurations of the Weather Research and Forecasting (WRF) model over the United Arab Emirates (UAE) and the Middle‐East at the convective gray‐zone resolution (9km) are evaluated in their ability to capture the temporal and spatial distributions of precipitation. Annual rainfall over the Middle‐East is dominated by wintertime precipitation

The Tibesti Volcanic Province (TVP) in northwest Chad represents the second largest of the five Gharyan–Tibesti volcanic provinces and covers an area around 29,000 km2. The other four provinces are in Libya, but all five provinces are from late Miocene to Quaternary and may have a common mantle source. The TVP, however, differs from the other four as regards volcano-tectonic processes, eruption style

ABSTRACT The velocity pulses produced by forward-directivity effects in the near-fault regions can have destructive effects on structures. Proper estimation of the duration of such velocity pulses is an essential step in the near-fault seismic hazard analysis and mitigating potential damage. In this study, the effects of different source, path, source-to-site geometry, and local site parameters on

Production data from the Los Humeros geothermal field in Mexico are used to develop a forecast method for operation of the field in the future. This method supports understanding the limitations of sustainably exploiting a geothermal reservoir. Using such forecasts, fluid extraction could be scheduled in order to fulfill the steam demand of the installed capacity. Moreover, the forecast of the extraction

The frequent variability of petrophysical properties makes hydrocarbon exploration challenging in carbonate reservoirs. Nowadays, quantitative interpretation (QI) is an essential part of hydrocarbon exploration in a complex reservoir, which needs adequate rock physics data at the well level. However, sometimes the relevant data are not available in earlier discovered oil and gas fields. We observed

On January 24, 2020, Sivrice–Elazig–Turkey earthquake occurred along the East Anatolian Fault Zone. The moment magnitude of the event was reported as 6.8. This paper documents reconnaissance findings performed immediately after the event. Investigated sites namely, Lake Hazar shores, Karakaya Dam Reservoir–Euphrates River shores, Malatya–Battalgazi district and its villages, and Elazig Downtown are

Pulse-wave propagation velocity and resonance frequency measured in civil engineering structures are both related to structural design. Monitoring their variation following seismic strong shaking provides information about the immediate building capacity. Joint-interpretation of frequency and velocity variation requires a better understanding of the processes controlling seismic structural health.

Small structures in coal mine working face is one of the main hidden dangers of safe and efficient production in coal mine. Currently, seismic exploration is often used as the main method for detecting such structures. However, limited by the accuracy of seismic data processing and interpretation, the interpreted location of small structures is often deviated. Ground-penetrating radar (GPR) can detect

To improve the accuracy of inversion results, geological facies distributions are considered as additional constraints in the inversion process. However, the geological facies itself also has its own uncertainty. In this paper, the initial sedimentary facies maps are obtained by integrated geological analysis from well data, seismic attributes, and deterministic inversion results. Then the first iteration

Due to the induced polarization (IP) effect, the sign reversal often occurs in time-domain airborne electromagnetic (AEM) data. The inversions that do not consider IP effect cannot recover the true umderground electrical structures. In view of the fact that there are many parameters of airborne induced polarization data in time domain, and the sensitivity difference between parameters is large, which

Accurately estimated interval attenuation (1/Q) values have several applications, such as in quantitative interpretation and seismic resolution enhancement. Although Q values can be estimated by measuring the spectral ratio between seismic reflections from a target and a reference reflector, the results are influenced by factors such as overburden inhomogeneities. Here, we quantitatively analyze the

Parametric study was performed on the seismic stability of pile-anchor slope reinforcement structures for earth retaining wall with different structural parameters. Dynamic finite element analysis and the Newmark permanent displacement method were combined to derive the dynamic time-history response of the pile-anchor structure and evaluate slope seismic stability. The effects of pile embedment, pile

Fully recognize various problems in the observed magnetotelluric (MT) data is the precondition of inverse solutions. In the paper, according to the geomorphological conditions of the observational MT stations in the Guangxi area, we constructed several different kinds of models to conduct a three-dimensional forward simulation of the MT field using the vector finite element method (FEM). First, the

The constant Q property in viscoelastic media assumes that the quality factor Q does not change with frequency (i.e., the Q value is independent of the frequency). For seismic waves propagating in viscoelastic media, the wave equation is determined by the viscoelastic media model. Equivalence relations exist between various frequency domain mathematical models and physical rheological models for the

For logging while drilling (LWD) systems, it is necessary to adjust the working state of the downhole tools in real-time according to different operating conditions. In this paper, on the basis of the characteristics of LWD systems, a mud pressure-apperceived downlink system was examined. For the design of this system, a signal acquisition and processing board was created based on a piezoelectric ceramic

Time reversal is a key component of time-reverse migration and source location using wavefield extrapolation. The implementation of time reversal depends on the time symmetry of wave equations in acoustic and elastic media. This symmetry in time is no longer valid in attenuative medium. Not only the velocity is anisotropic in shale oil and gas reservoirs, but also the attenuation is usually anisotropic

Layikeleke copper deposit is a large-scale porphyry copper polymetallic buried deposit, which has been discovered recently in the eastern Junggar area of Xinjiang. Mineralization occurred in the Late Silurian and Early Devonian with the copper body mainly confined to tonalite. To find new ore bodies, it is necessary to map the 3D spatial distribution of the tonalite. For this reason, we deployed a

Surface observations and CHAMP measurement data are employed to develop a three-dimensional surface spline (3DSS) model of mainland China. The magnetic field distribution at the satellite level is then demonstrated using the model obtained. The results of this model are compared and verified by deriving the corresponding two (2DTY) and three-dimensional (3DTY) Taylor polynomial models. Issues such

Traditional unsupervised seismic facies analysis techniques need to assume that seismic data obey mixed Gaussian distribution. However, field seismic data may not meet this condition, thereby leading to wrong classification in the application of this technology. This paper introduces a spectral clustering technique for unsupervised seismic facies analysis. This algorithm is based on on the idea of

Digital core models reconstructed using X-ray tomography (X-CT) enable the quantitative characterization of the pore structure in three dimensions (3D) and the numerical simulation of petrophysics. When the X-CT images accurately reflect the micro structures of core samples, the greyscale threshold in the image segmentation determines the accuracy of digital cores and the simulated petrophysical properties

The mechanical behavior of rock materials is critically affected by water and temperature. To comprehensively study the coupled effects of water saturation and low temperature on the mechanical properties of sandstone, both quasistatic and dynamic compressive tests were performed on dry and water-saturated specimens under room temperature and -60°C. The results indicated that under the same strain

The understanding of earthquake physics is hindered by the poor knowledge of fault strength and temperature evolution during seismic slip. Experiments reproducing seismic velocity (∼1 m/s) allow us to measure both the evolution of fault strength and the associated temperature increase due to frictional heating. However, temperature measurements were performed with techniques having insufficient spatial

Field significance tests have been widely used to detect climate change. In most cases, a local test is used to identify significant changes at individual locations, which is then followed by a field significance test that considers the number of locations in a region with locally significant changes. The choice of local test can affect the result, potentially leading to conflicting assessments of

Rapid injection of MeV electrons associated with strong substorm dipolarization has been suggested as a potential explanation for some radiation belt enhancement events. However, it has been difficult to quantify the contribution of MeV electron injections to radiation belt enhancements. This paper presents two isolated MeV electron injection events for which we quite precisely quantify how the entire

Economic activities and the associated emissions have significantly declined during the 2019 novel coronavirus (COVID‐19) pandemic, which has created a natural experiment to assess the impact of the emitted precursor control policy on ozone (O3) pollution. In this study, we utilized comprehensive satellite, ground‐level observations, and source‐oriented chemical transport modeling to investigate the

We explore the changes in Southern Ocean upwelling patterns during the Last Glacial Maximum (LGM) and early deglaciation using a fully coupled climate model with ocean eddies parameterized via the Gent‐McWilliams scheme. Relative to the pre‐industrial climate, the model simulates an equatorward shift of the upwelling of the residual circulation in the Southern Ocean during the LGM, which is consistent

Cross‐shore transport of larvae, pollutants, and sediment between the surf zone and the inner shelf is important for coastal water quality and ecosystems. Rip currents are known to be a dominant pathway for exchange, but the effects of horizontal temperature and salinity gradients are not well understood. Airborne visible and infrared imaging performed on the California coast shows warm and cool plumes

In contrast to the modern‐day climate, North Pacific deep water formation and a Pacific Meridional Overturning Circulation (PMOC) may have been active during past climate conditions, in particular during the Pliocene epoch (some 3‐5 million years ago). Here, we use a climate model simulation with a robust PMOC cell to investigate the pathways of North Pacific deep water from subduction to upwelling

To examine the ocean acidification of coastal water as the result of the oceanic uptake of anthropogenic atmospheric CO2, we initiated acidification monitoring in the eastern part of the Tsugaru Strait, through which the Tsugaru Warm Current flows eastward from the Sea of Japan to the North Pacific. Annual mean pH and CaCO3 saturation state during 2012–2019 decreased considerably throughout all depths

Ground observation of precipitation over complex terrain is subject to large uncertainties due to inadequate sampling. This study explores a method that combines limited gauge data and a high‐resolution numerical simulation to quantify the precipitation uncertainties in central Himalaya. Specifically, the Coefficient of spatial Variability (CV) of precipitation and the minimum Number of Required Stations

A planetary mantle after core formation has been thought to be highly depleted in carbon due to its strong siderophile behavior. However, the carbon contents in lunar and terrestrial mantles are much greater than experimental predictions; thus, how the carbon contents in terrestrial mantles were established is puzzling and poorly understood. Here, we present high‐pressure experiments on the metal‐silicate

We use the OMI‐QA4ECV‐v1.1 NO2 tropospheric columns over the 10‐yr 2008‐2017 period to confront satellite‐based trends in NO2 concentrations to those from the state‐of‐the‐art regional chemistry‐transport model CHIMERE and to evaluate the bottom‐up anthropogenic and biogenic NOx emissions in Europe. A focus is made for the 30 most populated urban areas in Europe. Over urban areas in Western Europe

Projections of the sea level contribution from the Greenland and Antarctic ice sheets rely on atmospheric and oceanic drivers obtained from climate models. The Earth System Models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6) generally project greater future warming compared with the previous CMIP5 effort. Here we use four CMIP6 models and a selection of CMIP5 models to