Compact gravity inversion (CGI) is widely used to invert gravity data following the principle of minimising the volume of the causative body due to its simplicity, high efficiency, and sharp-boundary inversion results. In this study, the compactness weighting function is generalised and the depth weighting function is introduced to CGI to obtain the reweighted CGI (RCGI) method. Although RCGI exhibits

Land surface emissivity retrieval is important for the remote identification of natural materials and can be used to identify the presence of silicate minerals. However, its estimation from passive sensors involves an undetermined function related to radiance data, which is influenced by the atmosphere. We tested three methods for temperature emissivity retrieval in a dune field composed of 99.53%

Accurate determination of the Principal Slip Zone (PSZ) of earthquake fault zones is a key task of earthquake Fault Scientific Drilling for future earthquake control. The fault zone structure of Wenchuan earthquake is complex, and there are many strong earthquakes recorded on the fault zone, which make determining the PSZ in the Wenchuan earthquake Fault Scientific Drilling project-hole 1 (WFSD-1)

Intensive studies have been conducted on fluid-related seismic dispersion and attenuation in saturated anisotropic media. Most of the studies are concentrated on the transversely isotropy media. However, the fractures distribution in subsurface reservoirs is often complex. When there are multiple fracture sets developing in a porous background, the signatures of seismic dispersion and attenuation remain

The study intends to explore hydraulic and thermal properties of expansive soils treated with fibre, biochar and biochar–fibre mix. Both fibre and biochar are derived from coconut shell, which is highly common in coastal regions around the world. Besides, benefits, limitations and engineering feasibility of these geomaterials in green roofs are explored. Theoretical framework for thermal–hydraulic

Estimation of quartz content (QC) is important for gas hydrate production. However, the existing methods pay more attention to estimate saturations of hydrate or free gas instead of QC. QC is difficult to be estimated because of its limited and unclear influences on velocities in the hydrate-bearing sediments. A workflow was proposed to estimate QC from core to logging to seismic inversion whose core

In CSAMT exploration, the using of the artificial sources not only improves the signal-to-noise ratio of the data, but also brings a series of distortion effects, such as shadow and source overprint effects. This paper attempts to introduce a distortion effect caused by the target in the survey area. Although it is often ignored, it always plagues the data interpretation. In CSAMT method, the primary

Down-hole acoustic televiewer (ATV logging) is a geophysical well-logging device known to be able to reveal underground in-depth image. However, reviewing the current developments in the area of geotechnical engineering, ATV logging data were predominantly used for the purpose of visualizing and calculating the specific structural features in an open borehole, and nothing more. Noticeably, to the majority

Matching pursuit is able to decompose signals adaptively into a series of wavelets and has been widely applied in signal processing of the geophysical fields. Single-channel matching pursuit could not take into account the lateral continuity of seismic traces, and the recent multichannel matching pursuit exploits the lateral coherence as a constraint, which helps to improve the stability of decomposition

The mountainous catchments often witness contrasting regimes and the limited available meteorological network creates uncertainty in both the hydrological data and developed models. To overcome this problem, remotely sensed data could be used in addition to on-ground observations for hydrological forecasting. The fusion of these two types of data gives a better picture and helps to generate adequate

Shear wave splitting analysis to characterise lithospheric mantle anisotropy has been performed to provide better knowledge about lithospheric deformation and mantle flow beneath the Sunda–Banda arc transition, Indonesia. The tectonic setting of the study area is very complex characterised by the transition from subduction along Sunda arc to collision in Banda arc. The splitting measurements show lateral

Climate change is expected to adversely affect the coastal ecosystem in many ways. One of the major consequences of climate change in coastal areas is sea level rise. In order to manage this problem efficiently, it is essential to obtain reasonably accurate estimates of future sea level. This study focuses essentially on the identification of climatic variables influencing sea level and sea level prediction

The migration-based microseismic event location methods using waveform stacking algorithms are widely used for hydro-fracturing monitoring. These methods have the advantage of not requiring the accurate first arrival time around a detected event, which is more suitable for noisy data than classical travel time-based methods. However, accuracy of these methods can be affected under the condition of

The purpose of this study was to obtain the regional model of erosion according to the specific climatic, adaptive, and other conditions of the Toroq watershed located in the east north of Khorasan Razavi province. To conduct this research, first, the homogeneous units were prepared using slope maps, lithology, land use, and erosion forms in a Geographic Information System environment. Then, to optimize

The gamma-ray spectrum equipped with a high-purity germanium detector was used to measure the naturally occurring radioactive materials of groundwater samples resources from the petroleum-producing communities of Ma’rib Province—Yemen. Thirty-five samples were collected from different sites. The 40K, 232Th, and 226Ra activity concentrations of groundwater samples for oil and non-oil communities were

This study presents hazard estimation of Kashmir Basin, NW Himalaya using regional ground motion relations, representing one of the most seismically active region in the Himalayan belt. Fault-level seismic recurrence parameters are determined from an updated earthquake catalogue spanning from 25 to 2018 AD for all possible seismic sources. The estimated hazard maps are presented for three ground motion

Modeling of seismic wave propagation in areas with irregular topography is an important topic in the field of seismic exploration. As a popular numerical method for seismic modeling, the finite difference method is nontrivial to consider the irregular free surface. There have been extensive studies on the time-domain finite difference simulations with irregular topography; however, the frequency-domain

An Mw 6.8 earthquake occurred on October 25, 2018, 35 km offshore from the southwest coastlines of Zakynthos Island. The aftershock sequence appeared remarkably productive with six aftershocks of M ≥ 5.0 in the first month and tens of aftershocks with M ≥ 4.0 during the study period. The GCMT solution for the main shock suggests a very low angle plane (dip = 24°) for a dextral strike–slip faulting

Thunderstorm events usually take place in cumulonimbus clouds which are complemented with intense rainfall and high-speed winds. In general, rainfall parameter has massive significance when compared to other parameters. In this paper, a group of thunderstorm-related stability parameters were analyzed for pre-monsoon season only. Later, we also tried to study the association between thunderstorm-related

Water temperature is one of the most important indicators of aquatic system, and accurate forecasting of water temperature is crucial for rivers. It is a complex process to accurately predict stream water temperature as it is impacted by a lot of factors (e.g., meteorological, hydrological, and morphological parameters). In recent years, with the development of computational capacity and artificial

The Southwestern area of Fujian Province in China contains a major metallogenic belt. There have been three major tectonic movements since the Late Paleozoic, and the thrusts here are the main mineral deposits. These occurred between the Early Carboniferous and Late Permian eras. Due to dramatic undulations in the surface and associated complex underground structures, a single geophysical method cannot

A better understanding of intra/inter-annual streamflow variability and trends enables more effective water resources planning and management for current and future needs. This paper investigates the variability and trends of streamflow data from five stations (i.e. Ashti, Chindnar, Pathgudem, Polavaram, and Tekra) in Godavari river basin, India. The streamflow data were obtained from the Indian Central

Earthquakes are a major danger in a constantly growing society due to their imminent impact and power of destruction. Therefore, the idea of successfully forecasting an earthquake continues to motivate the multidisciplinary study of phenomena proposed as possible earthquake precursors such as ionospheric anomalies. In that sense, total electron content (TEC) has demonstrated to be an efficient parameter

Subsurface parameter reconstruction using full waveform inversion is highly nonlinear with nonunique solutions. When the initial model with high precision is missing, the cycle skipping problem will be encountered, especially for the strong scattering media like salt structures. In order to adapt to the inversion of strong scattering media, direct envelope inversion (DEI) using directly the envelope

The low-frequency seismic reflection is important for the characterization of hydrocarbon reservoirs. Previous research has proved that the frequency-dependent component of the low-frequency reflection coefficient is approximately proportional to the reservoir fluid mobility. A low-frequency seismic attribute is defined to extract an approximate measurement of reservoir fluid mobility from seismic

The conventional full-waveform inversion (FWI) often minimizes the objective function using some local optimization algorithms. As a result, when the initial model is not good enough, the inversion process will drop into a local minimum. The low-frequency components contained in seismic data are of vital importance for reducing the initial model dependence and mitigating the cycle-skipping phenomenon

The ionospheric total electron content (TEC) plays a major role in the estimation of positional accuracy of satellite-based navigation systems. TEC disturbs the transmission of the signal transmitted from the satellite to receiver, which leads to range error. Hence, the prediction of VTEC can rectify the range errors in advance. Navigation with Indian Constellation (NavIC) is a navigational satellite

A time-field search method was proposed for AE event source location, combining the grid search method and the database technique. Theoretical process was given, and laboratory hydraulic fracture stimulation experiments under true-triaxial confining stresses were performed to prove the practicability of the method. A regional velocity model with variable wave velocities and directionality was required

Malkara coals are located in the Oligocene-aged Danişmen Formation in the Thrace Tertiary coal basin. The Danişmen Formation consists of limestone, sandstone, tuffite, siltstone, claystone and intercalated coal. Elemental and specific natural radionuclide concentrations of lignites collected from Tekirdağ–Malkara coalfield were determined, and the associated radiological risk was assessed. In order

Climate change is a challenging global issue for the sustainable production of various crops around the world as change in climatic patterns can create a stressful environment for plant growth. This study assesses the impact of climate change on future water demand and sugarcane yield in Pakistan for the baseline (1981–2005) and future timescales (2020s, 2050s and 2080s). For evaluating the crop water

A new computing cluster has been operating since 2016 at the Institute of Meteorology and Water Management – National Research Institute. Increasing computing power enabled the implementation of ensemble prediction system forecasts in the operational mode and the use of a new computer for research purposes. As part of the priority project on “Study of Disturbances in the Representation of Modeling

The aim of this research is to assess relatively new hybrid methods for changes points and trends detection on rainfall series: Dynamic Programming Bayesian Change Point Approach (BA), Şen's innovative trend method (ITM) and its double (D-ITM) and triple (T-ITM) version using the multi-scale analysis of the discrete wavelet transform (DWT) as a coupling method. Three representatives rainfall stations

The development of temperature forecasting models for the state of Kerala using Seasonal Autoregressive Integrated Moving Average (SARIMA) method is presented in this article. Mean maximum and mean minimum monthly temperature data, for a period of 47 years, from seven stations, are studied and applied to develop the model. It is expected that the time-series datasets of temperature to display seasonality

Gravity data are often used for delineation of the lateral and vertical extension of mineralized bodies buried at different depths. Various parameters associated with the buried bodies are the primary concern for mineral exploration purposes. Hence, a reliable and efficacious interpretation method is developed for the delineation of gravity anomaly data over the 2D vertical and horizontal sheet with

In this study, an integrated approach has been adopted for optimum selection of locations for rain water harvesting (RWH) in Kohat district of Pakistan. Various thematic layers including runoff depth, land cover/land use, slope and drainage density have been incorporated as input to the analysis. Other biophysical criteria such as geological setup, soil texture and drainage streams characteristics

As one of the evaluation characteristics of shale sweet spots, the brittleness index (BI) of shale formations is of great significance in predicting the range of sweet spots, and guiding hydraulic fracturing. Based on the three elastic parameters of P-wave velocity (VP), S-wave velocity (VS) and density obtained by conventional prestack AVO inversion, BI can be calculated indirectly using the Rickman

The Indian Regional Navigation Satellite System (IRNSS) is a newly functional regional satellite navigation system around Indian subcontinent. It is also known as its functioning name of NaVIC, Navigation with Indian Constellation, working on L5 and S band. In this paper a compact and low cost circularly polarized microstrip patch antenna is proposed for IRNSS S band application, to provide single

The seismic records acquired during the 1994 MW6.7 Northridge earthquake provide important data for studying the pulse-like ground motions in the vicinity of reverse faults. We selected 106 horizontal records from 468 strong ground motion records in the near-field region and rotated the original records into fault-parallel and fault-normal orientations. Large velocity pulses were simulated by the 3D

Koyna region in western India experienced more than 1,00,000 earthquakes of different magnitudes (M ~ 1.0–6.3) in the past five decades. Earthquakes in this region are believed to be triggered by a change in fluid pressure due to the percolation of the reservoir (Koyna and Warna reservoir) water into the subsurface. A drilling program was set up by the Ministry of Earth Sciences, India and International

The gradient-based optimization methods are preferable for the large-scale three-dimensional (3D) magnetotelluric (MT) inverse problem. Compared with the popular nonlinear conjugate gradient (NLCG) method, however, the limited-memory Broyden–Fletcher–Goldfarb–Shanno (L-BFGS) method is less adopted. This paper aims to implement a L-BFGS-based inversion algorithm for the 3D MT problem. And we develop

The continuous shift of shoreline boundaries due to natural or anthropogenic events has created the necessity to monitor the shoreline boundaries regularly. This study investigates the perspective of implementing artificial intelligence techniques to model and predict the realignment in shoreline along the eastern Indian coast of Orissa (now called Odisha). The modeling consists of analyzing the satellite

The presence of seismic absorption distorts seismic record and reduces seismogram resolution, which can be partially compensated by application of absorption compensation algorithms. Conventional absorption compensation techniques are based on 1D forward model with each seismic trace being compensated independently. Therefore, the 2D results combined by each compensation trace may be noisy and discontinuity

Settling of solid particles in a stratified ambient fluid is a process widely encountered in geophysical flows. A set of experiments demonstrating the settling behaviour (the pattern of trajectory, variation of particle orientation, and settling velocity with depth) of thin disks descending through a nonlinear density transition was performed. The results showed complex hydrodynamic interactions between

This paper investigates the relationship between selected percentiles, return periods and the concepts of rare and extreme events in climate and hydrological series, considering both regular and irregular datasets, and discusses the IPCC and WMO indications. IPCC (Annex II: Glossary. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate

Site diversity gain prediction models were created to estimate mathematically the acquired benefits from the implementation of site diversity at place of choice. This work contributes to the comparison of existing gain prediction model to the gain of measured attenuation at Cyberjaya and Rawang, Malaysia. The experiment has been conducted for 4 years from 2014 to 2017, in Ka band using a large 7.3-m

An analysis of seismic risk using our tool QLARM has been performed for the Batken region including the cities of Aidarken and Kadamjay, 100 km SW of Osh. The damage to residential buildings and induced casualties has been estimated for a set of seismic scenarios of typical and maximum magnitude considering the existing seismicity data. Population and building datasets have been built based on up-to-date

With the development of oil and gas exploration, the conventional seismic migration imaging technology based on the isotropic assumption no longer meets our current requirements for high-resolution images. Migration in anisotropic media has become an essential requirement for oil and gas exploration. Marine seismic exploration has gradually entered the wide-azimuth and high-density seismic data acquisition

The goal of the study was to investigate if aviation emissions could influence the climate and weather by modifying the chemical composition of the atmosphere and subsequently, the radiative balance. To carry out the set objective, we used the global environmental multiscale atmospheric chemistry model with comprehensive tropospheric and stratospheric chemistry that is interactive with the radiation

This study was focused on evaluation of seismicity yield of key faults guarding the terrestrial Makran region (Balochistan and Iran) using updated datasets. The Makran onshore region is bounded by paramount strike-slip faults (Chaman fault, Ghazaband fault, Ornach-Nal fault and Minab fault). We have compiled the earthquake’s catalog and performed iterative processes for declustering of independent

This study investigates the potential of two evolutionary neuro-fuzzy inference systems, adaptive neuro-fuzzy inference system (ANFIS) with particle swarm optimization (ANFIS–PSO) and genetic algorithm (ANFIS–GA), in modelling reference evapotranspiration (ET0). The hybrid models were tested using Nash–Sutcliffe efficiency, root mean square errors and determination coefficient (R2) statistics and compared

Zoeppritz equations form the theoretical basis of most existing amplitude variation with incident angle (AVA) inversion methods. Assuming that only primary reflections exist, that is, the multiples are fully suppressed and the transmission loss and geometric spreading are completely compensated for, Zoeppritz equations can be used to solve for the elastic parameters of strata effectively. However,

A comprehensive review of the local scour due to vortical flow around a cylindrical bridge pier under steady current is presented in this paper. The mechanism of the formation of vortices, the size, velocity and strength of horseshoe vortex (HSV), formation of the HSV by the separation of laminar and turbulent boundary layer and the scour around a cylindrical pier due to vortices have been presented

Crosswell electromagnetic (EM) method has fundamentally improved the horizontal detection ability of well logging and will become an increasingly promising approach for the secondary exploration of hydrocarbon reservoir. We applied orthogonal least squares (OLS) radial basis function neural network (RBFNN) based on improved Gram–Schmidt (G–S) procedure to three-dimensional (3D) crosswell EM inversion

Chicxulub crater formed ~ 66 Ma ago by an asteroid impact on the Yucatan platform in the southern Gulf of Mexico. The crater has a ~ 200 km rim diameter and has been covered by carbonate sediments up to ~ 1.1 km thick in the central zone. Previous studies have identified the structure and major crater units through geophysical models from seismic reflection and potential field data, classified as the

Particulate matters (PMs) are considered as one of the air pollutants generally associated with poor air quality in both outdoor and indoor environments. The composition, distribution and size of these particles hazardously affect the human health causing cardiovascular health problems, lung dysfunction, respiratory problems, chronic obstructive pulmonary disease and lungs cancer. Classification models

The Mw7.0 Anchorage earthquake is most significant event since 1964 Mw9.2. Far away subduction zone trace, thus the seismogenic structure and failure plane are not clear and keep disputed. Based on published data, including faults, aftershock, focal mechanism solutions and source fault model and so on, we make comprehensive analysis and discussion. We think that this earthquake belongs to plate subduction

The study areas are located in Turkey (Kastamonu, Bartın, Karabük, Sivas) and contain very different rock types, various mining and agricultural activity opportunities. So, the areas have groundwaters that have different chemical compositions and electrical conductivity (EC) values. The EC can be measured using EC meter, and it must be measured in situ. But, the measurement of EC in situ is laborious

Sub-surface operations for energy production such as gas storage, fluid reinjection or hydraulic fracking may modify the physical properties of the rocks, in particular the seismic velocity and the anelastic attenuation. The aim of the present study is to investigate, through a synthetic test, the possibility of using empirical ground-motion prediction equations (GMPEs) to observe the variations in

Groundwater is the primary source of water for human development in the Yishu River basin, and therefore characterizing groundwater quality is essential for sustainable development of groundwater resources in the region. This study aimed to determine the hydrochemical characteristics and water quality of groundwater in the Yishu River basin by sampling 45 wells in October 2016 and May 2017. Hydrochemical

Flood is becoming an intensive hydro-climatic issue at the Kelantan River basin in Malaysia. Univariate frequency analysis would be unreliable due to multidimensional behaviour of flood, which often demands multivariate flow exceedance probabilities. The joint distribution analysis of multiple interacting flood characteristics, i.e. flood peak, volume and duration, is very useful for understanding