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Influence of CO 2 –water–rock interactions on the fracture properties of sandstone from the Triassic Xujiahe Formation, Sichuan Basin Acta Geophys. (IF 1.395) Pub Date : 2021-01-06 Hongfei Li, Lingzhi Xie, Li Ren, Bo He, Yang Liu, Jun Liu
Carbon dioxide (CO2) storage in deep saline aquifers has been lauded as one of the most effective techniques to mitigate greenhouse effects globally. Nevertheless, despite many investigations, clarifying the influence of CO2–water–rock interactions on the fracture characteristics of sandstone remains a challenge. In this work, the fracture properties of sandstone collected from the Triassic Xujiahe
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Prediction of the blast-induced ground vibration in tunnel blasting using ANN, moth-flame optimized ANN, and gene expression programming Acta Geophys. (IF 1.395) Pub Date : 2021-01-05 Abiodun Ismail Lawal, Sangki Kwon, Geon Young Kim
The blast-induced ground vibration (BIGV) is a severe environmental impact of blasting as it can affect the integrity of the structures and cause civil unrest. In this study, the BIGV of Daejeon tunnel was predicted taking into consideration parameters such as hole length, the charge per delay, number of holes, total charge, distance from the measuring station to the blasting point and the rock mass
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Extreme precipitation indices trend assessment over Thrace region, Turkey Acta Geophys. (IF 1.395) Pub Date : 2021-01-04 Sertac Oruc, Emrah Yalcin
The frequency and the severity of extreme weather events are increasing globally and will continue to do so in the coming decades as a consequence of our changing climate. Understanding the characteristics of these events is crucial due to their significant negative impacts on social, physical and economic environments. In this study, 14 extreme rainfall indices are determined and examined in terms
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Broadcast ionospheric delay correction algorithm using reduced order adjusted spherical harmonics function for single-frequency GNSS receivers Acta Geophys. (IF 1.395) Pub Date : 2021-01-04 M. S. R. Abhigna, M. Sridhar, P. Babu Sree Harsha, K. Siva Krishna, D. Venkata Ratnam
Single-frequency Global Navigation Satellite System (GNSS) users require an efficient ionospheric delay correction model for improving their positional accuracy. GPS satellite range signals undergo time delay through the inhomogeneous and dynamic state of the ionosphere. The ionospheric delay is inverse proportional to the signal frequency square due to the dispersive nature of the ionospheric medium
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Characterization of amplitude scintillation and distribution of positioning error for IRNSS/GPS/SBAS receiver Acta Geophys. (IF 1.395) Pub Date : 2021-01-04 Mitchell Prajapati, Abhishek Rawat, Shivam Sharma
Indian regional navigation satellite system (IRNSS) or Navigation with Indian Constellation (NaVIC) is the satellite-based navigation system, established and controlled by the Indian Space Research Organization. It provides services of positioning, velocity, and timing for civilian and military applications. Ionospheric irregularities cause the fluctuations in the amplitude and phase of the received
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Trend and nonstationary relation of extreme rainfall: Central Anatolia, Turkey Acta Geophys. (IF 1.395) Pub Date : 2021-01-03 Sertac Oruc
The frequency of extreme rainfall occurrence is expected to increase in the future and neglecting these changes will result in the underestimation of extreme events. Nonstationary extreme value modelling is one of the ways to incorporate changing conditions into analyses. Although the definition of nonstationary is still debated, the existence of nonstationarity is determined by the presence of significant
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Temporal and spatial trend analysis of rainfall on Bhogavo River watersheds in Sabarmati lower basin of Gujarat, India Acta Geophys. (IF 1.395) Pub Date : 2021-01-03 Pratik S. Patel, Shilpesh C. Rana, Geeta S. Joshi
Global warming is a biggest issue around the world. In this research paper, the temporal and spatial trend analysis of seasonal and annual rainfall on Bhogavo River watersheds in Sabarmati lower basin of Gujarat state of India has been analysed using the data of 11 rain gauge stations installed in Bhogavo watershed. Linear regression, Mann–Kendall Test, Sen’s slope test and innovative trend analysis
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Discrimination of earthquakes and quarries in the Edirne district (Turkey) and its vicinity by using a linear discriminate function method and artificial neural networks Acta Geophys. (IF 1.395) Pub Date : 2021-01-03 Aylin Tan, Gündüz Horasan, Doğan Kalafat, Ali Gülbağ
In this study, seismic events in the Edirne district (Turkey) and its vicinity have been investigated in order to discriminate earthquakes from quarry blasts. A total of 150 seismic events with Md ≤ 3.5 duration magnitude from a seismic activity catalog between 2009 and 2014 recorded by the Enez (ENEZ), Erikli (ERIK) and Gelibolu (GELI) broadband stations operated by Boğaziçi University, Kandilli Observatory
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Recognition of district-wise groundwater stress zones using the GLDAS-2 catchment land surface model during lean season in the Indian state of West Bengal Acta Geophys. (IF 1.395) Pub Date : 2021-01-02 Satiprasad Sahoo, Subha Chakraborty, Quoc Bao Pham, Ehsan Sharifi, Saad Sh. Sammen, Matej Vojtek, Jana Vojteková, Ismail Elkhrachy, Romulus Costache, Nguyen Thi Thuy Linh
Water is essential for irrigation, drinking and industrial purposes from global to the regional scale. The groundwater considered a significant water resource specifically in regions where the surface water is not sufficient. Therefore, the research problem is focused on district-wise sustainable groundwater management due to urbanization. The number of impervious surface areas like roofing on built-up
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Local scour due to water jet from a nozzle with plates Acta Geophys. (IF 1.395) Pub Date : 2021-01-02 Veysi Kartal, M. Emin Emiroglu
In this study, local scour occurring downstream from a nozzle with and without plates formed in cohesionless materials was investigated experimentally. The experiments were performed to determine scour geometry, maximum scour depth, and the effect of aeration on scour for water jets impinged obliquely into the downstream pool. Dimensionless variables affecting the scour were determined as densimetric
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A simplified approach for the evaluation of groundwater flow in stream–aquifer interaction Acta Geophys. (IF 1.395) Pub Date : 2021-01-02 Mamta Saxena, Rahul Kumar Singh
Stream–aquifer interaction process plays an important role in modulating flood wave propagation in a channel. The most elementary understanding of stream–aquifer interaction can be interpreted by the flux direction between a surface water body and the underlying aquifer. At the time of floods, stream stage rises, and the water gets infiltrated into the aquifer, and this process gets reversed at the
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Machine learning for predicting discharge fluctuation of a karst spring in North China Acta Geophys. (IF 1.395) Pub Date : 2021-01-01 Shu Cheng, Xiaojuan Qiao, Yaolin Shi, Dawei Wang
The quantitative analyses of karst spring discharge typically rely on physical-based models, which are inherently uncertain. To improve the understanding of the mechanism of spring discharge fluctuation and the relationship between precipitation and spring discharge, three machine learning methods were developed to reduce the predictive errors of physical-based groundwater models, simulate the discharge
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Visual and statistical inference of hourly and sub-hourly extreme rainfall trends Central Anatolia, Turkey case Acta Geophys. (IF 1.395) Pub Date : 2020-11-23 Sertac Oruc
The analysis of long-term rainfall data in a changing climate is important because it has many sectoral applications such as agriculture, infrastructure, and water resources management. Statistical analyses of the annual maximum rainfall data were performed using the Mann–Kendall (MK) trend test to evaluate the annual maximum trend characteristics of the rainfall time series, the innovative trend analysis
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Multi-trace post-stack seismic data sparse inversion with nuclear norm constraint Acta Geophys. (IF 1.395) Pub Date : 2020-11-21 Ronghuo Dai, Fanchang Zhang, Cheng Yin, Ying Hu
Among many seismic inversion methods, the sparse spike inversion for post-stack seismic data uses the migrated and stacked seismic data which is regarded as zero offset reflection seismic data in the case of normal incidence to extract reflectivity and impedance of underground rocks. The seismic reflectivity and impedance can reflect underground rocks’ lithology, petrophysical property, oil–gas possibility
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The stability of poro-elastic wave equations in saturated porous media Acta Geophys. (IF 1.395) Pub Date : 2020-11-20 Fansheng Xiong, Weitao Sun, Jiawei Liu
Poro-elastic wave equations are one of the fundamental problems in seismic wave exploration and applied mathematics. In the past few decades, elastic wave theory and numerical method of porous media have developed rapidly. However, the mathematical stability of such wave equations have not been fully studied, which may lead to numerical divergence in the wave propagation simulation in complex porous
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Study on the applicability of the SCS-CN-based models to simulate floods in the semi-arid watersheds of northern Algeria Acta Geophys. (IF 1.395) Pub Date : 2020-11-20 Ishak Abdi, Mohamed Meddi
Algeria has experienced catastrophic floods over the second half of the twentieth century, causing many deaths and extensive material damage. This study was conducted to find a suitable event-based rainfall-runoff (RR) model for semi-arid conditions, where continuous data are not available in all regional basins. The study compared, based on data availability, the SCS-CN model based on the antecedent
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Periods of refracted P-waves in coal seams and their applications in coal thickness estimations Acta Geophys. (IF 1.395) Pub Date : 2020-11-17 Zuiliang Liu, Ji Wang
The direct and accurate estimations of coal thicknesses are prerequisites for intelligent mining practices. One of the most effective methods for detecting the distributions of coal thicknesses in coal mining panels is the in-seam seismic (ISS) method. In the present study, after examining the formation processes and propagation characteristics of refracted P-waves in ISS data, it was concluded that
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Complex lithology prediction using mean impact value, particle swarm optimization, and probabilistic neural network techniques Acta Geophys. (IF 1.395) Pub Date : 2020-11-04 Yufeng Gu, Zhongmin Zhang, Demin Zhang, Yixuan Zhu, Zhidong Bao, Daoyong Zhang
Lithology prediction is a fundamental problem because the outcome of lithology prediction is the critical underlying data for some basic geological work, e.g., establishing stratigraphic framework or analyzing distribution of sedimentary facies. As the geological formation generally consists of many different lithologies, the lithology prediction is always viewed as a tough work by geologists. Probabilistic
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Daily streamflow prediction using support vector machine-artificial flora (SVM-AF) hybrid model Acta Geophys. (IF 1.395) Pub Date : 2020-11-04 Reza Dehghani, Hassan Torabi Poudeh, Hojatolah Younesi, Babak Shahinejad
Precise estimation of river flow in catchment areas has a significant role in managing water resources and, particularly, making firm decisions during flood and drought crises. In recent years, different procedures have been proposed for estimating river flow, among which hybrid artificial intelligence models have garnered notable attention. This study proposes a hybrid method, so-called support vector
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Effects of anisotropic changes on the conductivity of sedimentary aquifers, southeastern Niger Delta, Nigeria Acta Geophys. (IF 1.395) Pub Date : 2020-10-23 N. J George, N. E Bassey, A. M Ekanem, J. E Thomas
Sundry soils/rocks are characterized by electrical properties with clearly or obscurely expressed anisotropies. These anisotropic effects may be low, moderate or high depending on the coefficient of anisotropy (λ). The vertical electrical sounding technique employing Schlumberger electrode configuration and lithological information from boreholes were deployed to characterize the lithological diversity
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Numerical simulation of shear wave attenuation in borehole inserted by a horizontal fracture Acta Geophys. (IF 1.395) Pub Date : 2020-10-22 Binpeng Yan, Weiming Ou, Xingguo Huang, Nuno Vieira da Silva
The amplitude of shear waves is attenuated when passing through horizontal fractures crossing a borehole. In this study, we investigate the amplitude attenuation of shear waves throughout simulation of full-wave acoustic logging with the finite-difference method. As the fracture aperture is very small, it needs to be represented in a very fine gird when carrying out finite-difference simulation. Therefore
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Study on transmitted channel wave-based, horizontal multilayer 3-D velocity model inversion and quantitative coalbed thickness detection method Acta Geophys. (IF 1.395) Pub Date : 2020-10-22 Zean Hu, Pingsong Zhang, Guangzhong Ji, Xiaoyun Su
Most methods using transmitted channel wave (TCW) prospecting to quantitatively detect the thickness of coal seams based on the statistic relationship of group velocity in certain wave bands to the thickness of coal seams cannot be applied universally. To establish a universal applicable method, we first obtained the theoretical dispersion curve of TCW using the generalized reflection–transmission
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Seismic attributes via robust and high-resolution seismic complex trace analysis Acta Geophys. (IF 1.395) Pub Date : 2020-10-20 Mohsen Kazemnia Kakhki, Kamal Aghazade, Webe João Mansur, Franciane Conceição Peters
Seismic attribute analysis has been a useful tool for interpretation objectives; therefore, high-resolution images of them are of particular concern. The calculation of these attributes by conventional methods is susceptible to noise, and the conventional filtering supposed to lessen the noise causes the loss of the spectral bandwidth. The challenge of having a high-resolution and robust signal processing
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Impact of convection and stability parameters on lightning activity over Andhra Pradesh, India Acta Geophys. (IF 1.395) Pub Date : 2020-10-20 N. Umakanth, G. Ch. Satyanarayana, B. Simon, Prashant Kumar, M. C. Rao
This paper brings out the interconnection of flash rate density (FRD) with convection and stability parameters over Andhra Pradesh (AP), India. The convection parameters include rainfall, relative humidity, specific humidity, surface air temperature (SAT) and air temperature (at 850 mb). The stability parameters include convective available potential energy (CAPE), lifted index, K-index, total totals
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Space and time variability of meteorological drought in Syria Acta Geophys. (IF 1.395) Pub Date : 2020-10-19 Safwan Mohammed, Karam Alsafadi, Talal Al-Awadhi, Youssef Sherief, Endre Harsanyie, Ahmed M. El Kenawy
This study assesses the spatial and temporal characteristics (e.g., frequency, intensity, spatial extent) of meteorological drought in Syria. Specifically, drought was characterized using the observed rainfall data from 36 rain gauges spanning the period between 1990 and 2010 and covering the main climatic regions in Syria (i.e., Mediterranean, arid, semiarid and mountainous). Meteorological drought
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Generalisation and improvement of the compact gravity inversion method Acta Geophys. (IF 1.395) Pub Date : 2020-10-17 Wenwu Zhu, Junhuan Peng, Sanming Luo, Xiangang Meng, Jinzhao Liu, Chuandong Zhu
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
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Comparison of emissivity retrieval methods from ASTER data using Fourier-Transform Infrared Spectroscopy Acta Geophys. (IF 1.395) Pub Date : 2020-10-17 Silvia Beatriz Alves Rolim, Bijeesh Kozhikkodan Veettil, Pâmela Suélen Käfer, Atilio Efrain Bica Grondona, María Luján Iglesias, Lucas Ribeiro Diaz, Cristiano Lima Hackmann
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%
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Principal Slip Zone determination in the Wenchuan earthquake Fault Scientific Drilling project-hole 1: considering the Bayesian discriminant function Acta Geophys. (IF 1.395) Pub Date : 2020-10-13 Sinan Fang, Zhansong Zhang, Zhi Wang, Heping Pan, Ting Du
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)
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Viscoelasticity expression and extension of seismic dispersion and attenuation in porous media with multiple fracture sets Acta Geophys. (IF 1.395) Pub Date : 2020-10-13 Jinwei Zhang, Renwei Ding, Lihong Zhao, Deying Wang
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
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Utilization of coconut shell residual in green roof: hydraulic and thermal properties of expansive soil amended with biochar and fibre including theoretical model Acta Geophys. (IF 1.395) Pub Date : 2020-10-10 Hao Wang, Ankit Garg, Xiaoyong Zhang, Yangyang Xiao, Guoxiong Mei
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
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Rock-physics-based estimation of quartz content in the Shenhu area, South China Sea Acta Geophys. (IF 1.395) Pub Date : 2020-10-10 Wei Deng, Jinqiang Liang, Yulin He, Zenggui Kuang, Miaomiao Meng
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
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Distortion effects caused by target abnormal bodies in CSAMT exploration Acta Geophys. (IF 1.395) Pub Date : 2020-10-09 Xian-Xiang Wang, Ju-Zhi Deng, Jing-Li Ren
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
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An innovative application of borehole acoustic image and amplitude logs for geotechnical site investigation Acta Geophys. (IF 1.395) Pub Date : 2020-10-07 Hsien-Chang Kao, Po-Yi Chou, Hung-Chieh Lo
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
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Enhancing the resolution of time–frequency spectrum using directional multichannel matching pursuit Acta Geophys. (IF 1.395) Pub Date : 2020-10-06 Lu Xu, Xingyao Yin, Kun Li
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
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Improving ANN-based streamflow estimation models for the Upper Indus Basin using satellite-derived snow cover area Acta Geophys. (IF 1.395) Pub Date : 2020-10-06 Muhammad Hassan, Ishtiaq Hassan
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
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Lithospheric mantle anisotropy from local events beneath the Sunda–Banda arc transition and its geodynamic implications Acta Geophys. (IF 1.395) Pub Date : 2020-10-01 Syuhada Syuhada, Nugroho D. Hananto, Chalid I. Abdullah, Nanang T. Puspito, Titi Anggono, Febty Febriani, Bogie Soedjatmiko
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
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Sea level prediction using climatic variables: a comparative study of SVM and hybrid wavelet SVM approaches Acta Geophys. (IF 1.395) Pub Date : 2020-09-29 S. Sithara, S. K. Pramada, Santosh G. Thampi
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
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A migration-based location method using improved waveform stacking for microseismic events in a borehole system Acta Geophys. (IF 1.395) Pub Date : 2020-09-29 Qinghui Mao, Tahir Azeem, Xuliang Zhang, Yu Zhong, Yuan Fang, Yunxiao Zhang
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
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Evaluation of the efficiency of the rainfall simulator to achieve a regional model of erosion (case study: Toroq watershed in the east north of Iran) Acta Geophys. (IF 1.395) Pub Date : 2020-09-22 S Farajzadeh, M. R. Khaleghi
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
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The impact of the oil and gas industry on NORMs of groundwater and their annual effective dose in Ma’rib, central Yemen Acta Geophys. (IF 1.395) Pub Date : 2020-09-20 Mohsen M. M. Ali, Hongtao Zhao, Zhigang Li, O. M. H. Ahmed, Ibrahim Alfasatleh, Najeeb N. M. Maglas
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
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Hazard estimation of Kashmir Basin, NW Himalaya using probabilistic seismic hazard assessment Acta Geophys. (IF 1.395) Pub Date : 2020-09-20 Maqbool Yousuf, Kaiser Bukhari
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
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Frequency-domain elastic-wave modeling for polygonal topography using rotated average-derivative difference operators Acta Geophys. (IF 1.395) Pub Date : 2020-09-18 Zheng Li, Jing-Bo Chen, Jian Cao
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
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Relocation of the 2018 Zakynthos, Greece, aftershock sequence: spatiotemporal analysis deciphering mechanism diversity and aftershock statistics Acta Geophys. (IF 1.395) Pub Date : 2020-09-17 V. Karakostas, A. Kostoglou, D. Chorozoglou, E. Papadimitriou
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
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Analysis of various thermodynamic instability parameters and their association with the rainfall during thunderstorm events over Anakapalle (Visakhapatnam district), India Acta Geophys. (IF 1.395) Pub Date : 2020-09-14 N. Umakanth, G. Ch. Satyanarayana, B. Simon, M. C. Rao, M. Tanooj Kumar, N. Ranga Babu
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
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River/stream water temperature forecasting using artificial intelligence models: a systematic review Acta Geophys. (IF 1.395) Pub Date : 2020-09-14 Senlin Zhu, Adam P. Piotrowski
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
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Case study: joint seismic reflection and CSAMT data interpretation for mineral explorations in Fujian, China Acta Geophys. (IF 1.395) Pub Date : 2020-09-09 Guofeng Liu, Xiaohong Meng, Handong Tan, Zhaoxi Chen, Jianhui Ni, Lanbo Liu
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
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Seasonality shift and streamflow flow variability trends in central India Acta Geophys. (IF 1.395) Pub Date : 2020-09-04 Alban Kuriqi, Rawshan Ali, Quoc Bao Pham, Julio Montenegro Gambini, Vivek Gupta, Anurag Malik, Nguyen Thi Thuy Linh, Yogesh Joshi, Duong Tran Anh, Van Thai Nam, Xiaohua Dong
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
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Examination of seismo-ionospheric anomalies before earthquakes of M w ≥ 5.1 for the period 2008–2015 in Oaxaca, Mexico using GPS-TEC Acta Geophys. (IF 1.395) Pub Date : 2020-09-02 Angela Melgarejo-Morales, G. Esteban Vazquez-Becerra, J. R. Millan-Almaraz, R. Pérez-Enríquez, Carlos A. Martínez-Félix, J. Ramon Gaxiola-Camacho
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
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Fault modelling, seismic sequence evolution and stress transfer scenarios for the July 20, 2017 ( M W 6.6) Kos–Gökova Gulf earthquake, SE Aegean Acta Geophys. (IF 1.395) Pub Date : 2020-09-01 Sotirios Sboras,Ilias Lazos,Evaggelos Mouzakiotis,Vassilios Karastathis,Spyros Pavlides,Alexandros Chatzipetros
The July 20, 2017, M W 6.6 Kos–Gökova Gulf earthquake occurred offshore, near Bodrum of Turkey and Kos of Greece. It was one of the strongest in the broader area during the last many decades causing two deaths, many injuries and extensive damages. We investigated the evolution of the seismic sequence using seismological and geological tools. The aftershock sequence was relocated mainly in order to
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A new multi-scale signed direct envelope inversion with more accurate amplitude polarity information Acta Geophys. (IF 1.395) Pub Date : 2020-08-29 Jingrui Luo, Guoxin Chen, Ru-Shan Wu, Lu Wang
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
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Low-porosity and low-permeability reservoirs characterization using low-frequency seismic attribute Acta Geophys. (IF 1.395) Pub Date : 2020-08-28 Jing Zeng, Handong Huang, Sanyi Yuan, Chunhua Wu
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
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Frequency extension and robust full-waveform inversion based on n th power operation Acta Geophys. (IF 1.395) Pub Date : 2020-08-27 Pan Zhang, Liguo Han, Rui Gao, Fengjiao Zhang, Zhenzhen Xing
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
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Ordinary kriging - and cokriging - based surrogate model for ionospheric TEC prediction using NavIC/GPS data Acta Geophys. (IF 1.395) Pub Date : 2020-08-20 R. Mukesh, V. Karthikeyan, P. Soma, P. Sindhu
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
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A time-field search method for AE source location with a regional velocity model Acta Geophys. (IF 1.395) Pub Date : 2020-08-14 Shunchuan Wu, Yixiong Gan, Jesse Hampton, Marte Gutierrez, Mingjing Lu, Xiaoqing Huang
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
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Radioactivity concentrations and risk assessment of Tekirdağ lignites (case study of Malkara coalfield) Acta Geophys. (IF 1.395) Pub Date : 2020-08-13 C. Bertan Güllüdağ, Ercüment Aksoy, Neslihan Ünal, Süleyman Fatih Özmen
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
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Assessing the impact of climate change on sugarcane and adaptation actions in Pakistan Acta Geophys. (IF 1.395) Pub Date : 2020-08-13 Nageen Farooq, Shabbir H. Gheewala
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
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Dependence of skill and spread of the ensemble forecasts on the type of perturbation and its relationship with long-term norms of precipitation and temperature Acta Geophys. (IF 1.395) Pub Date : 2020-08-12 Grzegorz Duniec, Andrzej Mazur
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
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The use of hybrid methods for change points and trends detection in rainfall series of northern Algeria Acta Geophys. (IF 1.395) Pub Date : 2020-08-11 Bilel Zerouali, Mohamed Chettih, Zaki Abda, Mohamed Mesbah, Mohammed Djemai
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
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Trend analysis and SARIMA forecasting of mean maximum and mean minimum monthly temperature for the state of Kerala, India Acta Geophys. (IF 1.395) Pub Date : 2020-07-16 P. Kabbilawsh; D. Sathish Kumar; N. R. Chithra
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
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Interpretation of gravity anomaly over 2D vertical and horizontal thin sheet with finite length and width Acta Geophys. (IF 1.395) Pub Date : 2020-07-16 Arkoprovo Biswas
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
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