The North–South Seismic Belt distributed along the eastern margin of the Tibetan Plateau is a regional-scale seismically active zone. The Yuanmou Fault, located at the junction of the North–South Seismic Belt and the Central Yunnan Sub-Block, is an important boundary of earthquakes distribution and topography. Therefore, the studying of the Late Quaternary activity of the Yuanmou Fault is of great

The electrical conductivity and wave velocity of basalt are important parameters for analyzing the evolution of the crust and mantle; they are also used in many fields, such as underground engineering. To analyze the influences of pressure and temperature on the electrical conductivity and wave velocity of basalt, this review summarizes many relevant references. The results show that mineralogical

Fracture or fault can control several geological or geophysical events and exploration, where the fault associated with mineralization or fluid flow can be used as a source for Self-Potential (SP) anomaly. The 2-D inclined sheet can be used for modeling for fault interpretation using SP data. In this paper, the improved crow search algorithm (ICSA) using Levy flight is proposed for SP data inversion

Inter-Satellite Links (ISLs) are intended to improve precision of orbit determination and satellite clock estimation. The ISLs provide a precise pseudorange measurements between satellites in a specific constellation. The study is a preparatory assessment of exploitation of seven connectivity schemes in the terms of the precise orbit determination for three types of constellations—Galileo-like with

A model describing the frequency distribution of geomagnetic field fluctuations has been developed, allowing a better understanding of the influence of the solar magnetic field on the geomagnetic variations. The constructed model is analogous to the one presented by same authors in 2018 to describe the frequency distribution of seismic magnitudes. A similarity between seismic and geomagnetic systems

In the article On the impact of correlations on the congruence test: a bootstrap approach, Table 1 should be corrected to.

Ionospheric peak electron density (NmF2) and total electron content (TEC) are the essential measures of ionospheric variability for modeling their effects on navigation and communication system applications. The global and regional models have their limitations in predicting ionospheric variations at the low latitude Indian region, mainly due to the anomalous electron density gradients and equatorial

The solar flares and geomagnetic storms are considered a potential threat for the upcoming Indian Regional Navigation Satellite System or Navigation with Indian Constellation (NavIC). Therefore, we investigated in detail the occurrence of tracking failure and effects on the positional accuracy of the NavIC L5-band and S-band system under direct exposure of X2.2 and X9.3 solar flare on September 6,

The objective of this paper is to present a new approach for forecasting NAO index (NAOi) based on predictions of sea level anomalies (SLAs). We utilize significant correlations (Pearson’s r up to 0.69) between sea surface height (SSH) calculated for the North Atlantic (15–65°N, basin-wide) and winter Hurrell NAOi, as shown by Esselborn and Eden (Geophys Res Lett 28:3473–3476, 2001). We consider the

To quantitatively understand the geodynamic process of a region, study of geothermal parameters underneath the earth surface is very paramount. Curie depth can be an alternative to delineate geothermal parameters. In the present study, we estimated Curie depths from the power spectra of 25 equally window sizes areas/points with 50% overlap extracted from high-resolution aeromagnetic anomalies of parts

Between February 16 and April 5, 2019, a series of earthquakes took place around the village of Somogyszob, Somogy county, Hungary. The mainshock occurred on March 7 with a local magnitude \(M_L=4.0\) and epicentral intensity of 5 on the EMS scale. The main event was preceded by four foreshocks and followed by four aftershocks. The largest foreshock (\(M_L=2.6\)) was also felt with maximum intensity

Superconducting gravimetry is one main technique to determine the gravity tides. In superconducting gravimeter (SG) measurement, the gravity tides is affected by the gross errors (including spikes and severe deviations and mainly caused by instrument problems and earthquakes) and noise (caused due to the internal structure of SG instrument and measurement environment) in SG data. The singular spectrum

A summary of methods yielding information about the generation and configuration of the geomagnetic main field is presented with special focus on complications concerning these methods. A global source model constructed with the help of machine learning (and deep learning) is proposed to mitigate these issues, in particular the uncertainties caused by vigorous convection and small scale fields.

The revolutionary approach to determining self-noise of the test seismometer by the use of two additional seismometers was presented by Sleeman et al (Bull Seismol Soc Am 96(1):258–271, 2006). Yet nowadays there are common situations where only two seismometers are installed side by side. This article thus outlines the various procedures that can be used in such situations. As it will be shown by examples

Integer ambiguity resolution is critical for achieving positions of high precision and reliability of precise point positioning (PPP). However, as an important error source in global navigation satellite system (GNSS), multipath interference limits the ability of PPP in high-accuracy GNSS positioning applications. Thus, to guarantee the performance of PPP ambiguity resolution techniques in a multipath

This study used the double-difference seismic tomography method to obtain the upper crustal velocity structure in Laizhou Bay and its adjacent areas (LBAA). We found that the horizontal and vertical distributions of the earthquakes after relocation in earthquake swarms are more concentrative than that before relocation. The lateral heterogeneity of crustal velocity structure near the surface in the

China-Pakistan Economic Corridor (CPEC) is the ongoing mega construction project in Pakistan. This project provides multi trading routes like roads, railways and fiber optics to more than 70 countries. Additionally, local infrastructure and industrial zones construction in Pakistan is also the part of this project. This construction needs a considerable amount of construction materials. Therefore,

The detection of deformation is one of the major tasks in surveying engineering. It is meaningful only if the statistical significance of the distortions is correctly investigated, which often underlies a parametric modelization of the object under consideration. So-called regression B-spline approximation can be performed for point clouds of terrestrial laser scanners, allowing the setting of a specific

The height of the development of a caved zone (CZ) and a water-conducting fractured zone (WCFZ), hereinafter “CZ and WCFZ”, in mining of soft coal with a soft mine floor, hard mine roof and different thicknesses of the coal seam, hereinafter “two soft and one hard” unstable coal seam, is of interest in the long wall coal mining. An observation borehole was drilled above a coal seam with an average

Analyzing the partitioning of stress and deformation in active orogenic settings is of fundamental importance for understanding the mechanisms driving the geodynamic evolution and seismicity, particularly in complex orogenic settings. In this respect, a quantitative understanding is obtained by coupling the large-scale geodynamic evolution with partitioning of local deformation and stress patterns

Anomalies in the Radon activity concentration time series recorded in five European caves (Czech Republic, Slovakia, Slovenia) are detected using three hybrid methods: (1) multiple linear regression and autoregressive integrated moving average statistical methods, (2) Empirical Mode Decomposition with Support Vector Regression techniques and (3) the Singular Spectrum Analysis composed with a predicting

This study proposes a model for a BeiDou Satellite Navigation System (BDS) precise timing solution with un-differenced carrier phase observations, and it is suitable for both single-station and multi-station. With this model, not only can users employ high-precision carrier phase observations to improve the uncertainty of the timing service for single station, but they can also directly use the un-differenced

In Biot theory, the relative velocity between fluid and solid and their relative acceleration, via Darcy permeability and the coupling factor, respectively, are used to quantify stress between the phases. In this paper, the relative velocity via variable permeability is used to improve the quantification of the stress. The modeling quantities are the S-wave velocity ratio of brine saturated Berea sandstone

In this paper first, the method used for solving the weighted total least squares is discussed in two cases; (1) The parameter corresponding to the erroneous column in the design matrix is a scalar, model \(({\mathbf{H}} + {\mathbf{G}})^{T} {\mathbf{r}} + \delta \, = {\mathbf{q}} + {\mathbf{e}}\), (2) The parameter corresponding to the erroneous column in the design matrix is a vector, model \(({\mathbf{H}}

Gravity Recovery and Climate Experiment (GRACE) satellite mission had provided gravity data for ca. 15 years, completed its mission in 2017 and handed over to GRACE Follow-On. During its active life, GRACE contributed to the understanding of temporal variations of geoid/quasigeoid heights as well as vertical and horizontal displacements of the Earth’s surface induced by mass loading, and thereby the

In this paper a new method of numerically solving ordinary differential equations is presented. This method is based on the Gaussian numerical integration of different orders. Using two different orders for numerical integration, an adaptive method is derived. Any other numerical solver for ordinary differential equations can be used alongside this method. For instance, Runge–Kutta and Adams–Bashforth–Moulton

The study of climate change is an important field of research. Monitoring of atmospheric variability especially the tropospheric precipitable water vapor (PWV) is a powerful way to investigate climate change. Global navigation satellite systems (GNSS) provide a good tool for studying atmospheric parameters as GNSS signals along its path from the satellites to the ground based receivers suffer a significant

In a non-line-of-sight (NLOS) environment, high accuracy ultra-wideband (UWB) positioning has been one of the hot topics in studying indoor positioning. Aiming at the UWB and inertial measurement unit (IMU) fusion vehicle positioning, a constraint robust iterate extended Kalman filter (CRIEKF) algorithm has been proposed in this paper. It has overcome the innate defect of the extended Kalman filter

The ionospheric anomalies are often responsible for compromising the accuracy and performance of Global Navigation Satellite System (GNSS). GPS Aided Geo Augmented Navigation (GAGAN) is the autonomous Space Based Augmentation System of India which serves to provide timely error detection and correction for the corrupted GNSS signals in aircrafts. This paper discusses a Maximum Minimum Eigen (MME) detector

Investigations of hydraulically induced micro-seismicity are typically connected with magma injections, exploitation of geothermal fields and salt mines. Our study examines the seismicity and seismic sources in a peri-platform region with long salt production history. In addition, a very large site for extraction of aggregates and limestone is presented in the area. Increased seismicity in the region

As a kind of geomagnetic data processing, downward continuation of potential field plays an important role in geologic interpretation and geomagnetic localization. The inherent instability of larger distance downward continuation restricts its practical applications. In this paper, we report a kind of one-step compensation downward continuation method free of iteration using the equivalent wave number

The self potential data interpretation is very important to delineate and trace the mineralized zones in several regions. We study how to interpret self potential anomalies due to a finite two-dimensional inclined dike using the particle swarm algorithm. However, the precise estimation of the model parameters during the inverse solution are unknown. Here, we show that the particle swarm algorithm is

As one of the major regions of carbonate rock oil–gas exploration in western China, Tazhong area of the Tarim Basin has severe environment and complex ground surface conditions, hence the signal to noise ratio (SNR) of the field seismic data is extremely low. To improve the SNR of desert seismic data is a crucial step in the following work. However, the random noise in desert seismic characterizes

The propagation characteristics of crustal Lg waves have been investigated in and around geotectonically complex Indo-Burman Ranges (IBR) of North Eastern region (NER) of India. To cater towards seismic hazard assessment and civil engineering practices, Lg attenuation has been studied by determining the regional average quality factor (QLg) in the frequency range of 0.5–5 Hz. The Lg attenuation regional

Elimination of random noise is crucial in seismic data processing. Especially in desert area, field record generally has problems of weak effective reflection wave and strong noise due to its special surface factors. Besides, desert noise has characteristics of low-frequency, non-stationary and non-Gaussian. Thus, it is difficult to separate the effective signal from desert noise in low-frequency band

Reservoir evaluation of tight sandstone involves the determination of reservoir properties from samples and logs. In the calculation of water saturation, Archie formula is an important fundamental and connection between log evaluation and petrophysics. Highly accurate parameters of Archie formula are the key to the log evaluation of gas-bearing tight sandstone. At present, there are two methods of

By utilizing data from the National Seismic-Monitoring Network of Turkey, operated by AFAD (Disaster and Emergency Management Presidency, Ministry of the Interior), power spectra of 198 stations distributed countrywide are computed and probability density functions as well as diurnal, weekly, monthly and annual spectrogram-graphics, hence, are obtained. Observed noise levels are the result of natural

In precise point positioning (PPP), the zenith hydrostatic delay (ZHD) is traditionally treated as a priori value from the ZHD model but the zenith wet delay (ZWD) is treated as an unknown parameter to estimated. For some near real-time PPP tasks, priori ZHD from the blind ZHD models are often used because external meteorological measurement or information about atmospheric pressure or ZHD can not

Ionospheric anomalies have been shown to occur a few days before several large earthquakes. The published works normally address examples limited in time (a single event or few of them) or space (a particular geographic area), so that a clear method based on these anomalies which consistently yields the place and magnitude of the forthcoming earthquake, anytime and anywhere on earth, has not been presented

A collapse column is a geological structure formed by the dissolution of a soluble rock layer under certain hydrogeological conditions. This forms a cavity, which is filled by the overburden. Collapse columns have a great impact on coal mining safety. In this work, a model of a concealed collapse column is constructed according to its diameter, and the finite difference method is used to simulate it

AbstractThe Global Positioning System (GPS) permanent stations at the equatorial and southern sub-tropical hydrobelts of South America undergo the highest seasonality on the Earth due to hydrological loadings. Fortunately, there are products that account for such variations, although some of them have not been properly evaluated. For instance, global solutions of Gravity Recovery and Climate Experiment

The results of mathematical modeling of electrical soundings with the AMNB (Schlumberger, Wenner) arrays and the proposed combined AMN + NMA array above horizontally layered medium and including a ball medium are presented. It is shown that the combined array has two main advantages: the current penetration depth is greater at the same position of outer electrodes of the considered arrays; edge effects

As a preliminary three-dimensional numerical analysis, this research aims to detect future zones of high-stress accumulation caused by the interaction of active faults within a 3D topographic geological block based on finite-element analysis. Stress analysis of the three-dimensional topographic model covers both static and dynamic loading caused by topographic loads and crustal movements, and can provide

Burdur Fault (BF) is located in Fethiye Burdur Fault Zone and it has formed in three main sections as Gölbaşı–Gökçebağ, Burdur and Yassıgüme–Çendik. The Neogene Basin is a NE–SW oriented depression basin which forms Plio-Quaternary aged lacustrine and alluvial deposits. Paleo-seismic structures on lacustrine sediments were studied with three excavation surfaces at the BF segments in Burdur settlement

The study area comprises the NE–SW trending Burdur Basin situated at the tectonically active northeastern part of the Fethiye–Burdur Fault Zone (FBFZ), SW Turkey. The basin demonstrates a half graben geometry hosting lacustrine sedimentary deposits from the Late Miocene onward and is bounded by normal faults on its southern side namely the Burdur Fault Zone. In this study, gravity anomalies over the

Earth Rotation Parameters (ERP) are indispensable in the transformation between the Celestial Reference Frame and the Terrestrial Reference Frame, and significant for high-precision space navigation and positioning. As a key parameter in ERP, Polar Motion (PM) is of great importance in analyzing and understanding the dynamic interaction between solid Earth, atmosphere, ocean and other geophysical fluids

A combined empirical mode decomposition (EMD) and multichannel singular spectrum analysis (MSSA) model (EMD–MSSA model) was used for extraction of the gravity tide correction without a priori information (e.g., station coordinates) from static relative gravimetric data. Static observational data acquired using a CG-5 relative gravimeter over 16 days were used to investigate the feasibility and reliability

The Least-squares extrapolation of harmonic models and autoregressive (LS + AR) prediction is currently considered to be one of the best prediction model for polar motion parameters. In this method, LS fitting residuals are treated as data to train an AR model. But it is readily known that using too many data will result in learning a badly relevant AR model, implying increasing the model bias. It

This paper proposes a heuristic singular spectrum analysis (SSA) approach to extract signals from suspended sediment concentration (SSC) time series contaminated by multiplicative noise, in which multiplicative noise is converted to approximate additive noise by multiplying with the signal estimate of the time series. Therefore both the signal and noise components need to be recursively estimated.

Ultra-rapid clock products provide the main parameters for real-time or near real-time precise point positioning services. However, it has been found that BeiDou ultra-rapid clock offsets do not meet the requirements for high-accuracy applications because of their low accuracy, especially regarding the prediction parts. This study proposes an improved model for BDS satellite ultra-rapid clock offset

The signal-in-space (SIS) anomalies caused by satellites and control segments can greatly affect the reliability and safety of navigation and positioning users. The prior information associated with the failure of the Advanced Receiver Autonomous Integrity Monitoring (ARAIM) algorithm were obtained by the evaluation of SIS failure rates broadcasted with navigation ephemeris to investigate the integrity

The Pannonian region is a back-arc basin located within the arcuate Alpine–Carpathian mountain chain in central Europe. Beneath the basin both the crust and the lithosphere have smaller thickness than the continental average. During the last few decades several studies have been born to explain the formation of the Pannonian Basin but several key questions remain unanswered. In this study we construct

A comprehensive robust inversion-based Fourier transformation algorithm has been proposed based on the advantages of Hermite functions for processing even in random-walk data known as the iteratively reweighted least squares fourier transformation (IRLS-FT) method. By using Hermite functions as the basis functions of discretization, the Fourier spectrum was discretized using a series expansion of which

An accurate tensor estimation function is a guarantee for acquiring a reliable underground electrical structure model. The past studies regarding transmission functions aim at obtaining smooth and continuous sounding curves through the time domain by data screening means such as least square, robust and remote reference processing methods as well as digital filtering techniques such as wavelet denoising

The indoor positioning technology is based on the hotpots of location based services (LBS). However, most indoor positioning systems are two-dimensional and couldn’t meet the requirements of today’s LBS. The complex indoor structures and environment determine the floor positioning rather than the altitude positioning in the vertical direction, so the floor identification is the key to three-dimensional

The ground-based GNSS VTEC model can adequately capture the spatiotemporal characteristics of ionosphere activities. However, it is difficult to precisely model VTECs with a unified mathematical model. We dedicate to comprehensively assess the performance of four mathematical models for VTEC modeling, i.e., polynomial, trigonometric series, spherical harmonic and multi-surface function. To capture

In the near future, the upcoming Navigation through Indian Constellation (NavIC) system will be used for navigation services in India. All services provided by the NavIC receiver must be reliable and resistant to threats. Therefore, the real-time NavIC signal is examined under intentional software defined radio based chirp-jamming by different methods. Since the NavIC signal is available for all the

For many years, the adaptation of the historical maps to those used today has been one of the fields of study of cartography and geodesy. In this process, the first problem is that the coordinate system in historical maps differs from the modern coordinate systems. For such problems, many mathematical methods have been developed and implemented for the georeferencing process. The second problem, more

The site characterisation of future underground gravitational wave detectors is based on spectral properties of the low frequency seismic noise. The evaluation of the collected long term seismological data in the Mátra Gravitational and Geophysical Laboratory revealed some aspects that are not apparent in short term spectral noise characterisation. In this paper we survey the methodology. In particular

Benford’s law (BL), also known as the first-digit or significant-digit law, is an intriguing pattern in data sets, considers the frequency of occurrence of the first digits, which are not uniformly distributed as might be expected, conversely follow a specified theoretical distribution. According to BL, the occurrence of first non-zero digit in a numerical data, which is generated or found in nature