{"title":"Multi-GNSS positioning for landslide monitoring: a case study at the Recica landslide","authors":"Weiguo Li","doi":"10.13168/agg.2022.0011","DOIUrl":"https://doi.org/10.13168/agg.2022.0011","url":null,"abstract":"","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42355637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a scheme of signal extraction and modeling for GNSS position time series based on Monte Carlo Multi-channel Singular Spectrum Analysis (MC-MSSA) is introduced, which can effectively consider the spatial correlation of different directions by processing the different components of position time series at the same time. Meanwhile, the Monte Carlo significance test is utilized to distinguish the signal from the colored noise. By comparing with Singular Spectrum Analysis (SSA), it can be confirmed that MSSA has better signal extraction and modeling performance by taking into account the correlation of different channels. Then, taking the LHAZ station as an example, MC-MSSA is utilized to simultaneously model the three components o f GNSS position time series, and the trend and periodic signals are respectively identified by Kendall nonparametric test and W-correlation correlation analysis. The result denotes that MC-MSSA can effectively model the tectonic and non-tectonic signals of GNSS position time series, and the modeled signals can more intuitively reflect the dynamic movement of the station. Finally, based on the MC-MSSA-modeled tectonic signal, we characterize the crustal deformations around the eastern Tibetan Plateau, mainly including the crustal movement and strain rate change. The results suggest that the pushing movement of the Tibetan Plateau from the Indian plate is blocked by the South China block, and the crustal movement rate is obviously decreased and appears a right-handed movement trend. Meanwhile, the junction of the Tibetan Plateau and South China block has accumulated a certain amount of stress, and the tectonic activity at the junction is relatively strong and still belongs to the dangerous zone of seismic activity.
{"title":"Monte Carlo MSSA to modeling GNSS position time series and its implication for crustal deformation monitoring","authors":"Yunfei Xiang","doi":"10.13168/agg.2022.0010","DOIUrl":"https://doi.org/10.13168/agg.2022.0010","url":null,"abstract":"In this paper, a scheme of signal extraction and modeling for GNSS position time series based on Monte Carlo Multi-channel Singular Spectrum Analysis (MC-MSSA) is introduced, which can effectively consider the spatial correlation of different directions by processing the different components of position time series at the same time. Meanwhile, the Monte Carlo significance test is utilized to distinguish the signal from the colored noise. By comparing with Singular Spectrum Analysis (SSA), it can be confirmed that MSSA has better signal extraction and modeling performance by taking into account the correlation of different channels. Then, taking the LHAZ station as an example, MC-MSSA is utilized to simultaneously model the three components o f GNSS position time series, and the trend and periodic signals are respectively identified by Kendall nonparametric test and W-correlation correlation analysis. The result denotes that MC-MSSA can effectively model the tectonic and non-tectonic signals of GNSS position time series, and the modeled signals can more intuitively reflect the dynamic movement of the station. Finally, based on the MC-MSSA-modeled tectonic signal, we characterize the crustal deformations around the eastern Tibetan Plateau, mainly including the crustal movement and strain rate change. The results suggest that the pushing movement of the Tibetan Plateau from the Indian plate is blocked by the South China block, and the crustal movement rate is obviously decreased and appears a right-handed movement trend. Meanwhile, the junction of the Tibetan Plateau and South China block has accumulated a certain amount of stress, and the tectonic activity at the junction is relatively strong and still belongs to the dangerous zone of seismic activity.","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45713454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main target of the present study is to investigate the foundation layers and the subsurface structures in an Egyptian solar plant site using geophysical techniques including the seismic refraction and Multichannel Analysis of Surface Waves (MASW). The studied solar park is situated at about 40 km to the north of Aswan city on the Aswan-Cairo highway road and is classified as the largest solar plant in Africa and worldwide. Due to its location in the vicinity of the most prone earthquake area in Egypt (Aswan seismic zone); it is imperative to mitigate the earthquake hazard in this region. The geophysical results show that the subsurface foundation in this site is primarily composed of two layers. The upper one is loose and incompetent soil sediments that extend down to about 10 m depth with P-wave velocity ranging from 400 to 1000 m/s and shear-wave velocity ranging from 260 to 550 m/s. The deeper section is considered the main foundation layer with velocities ranging between 650 and 1900 m/s and from 350 to 950 m/s for P-wave and shear-wave, respectively. The average shear-wave velocities calculated for the topmost 30 m (Vs 30 ) vary almost between 319 and 834 m/s; thereby the studied site is primarily ranked into classes C&D (180-360 m/s & 360-760 m/s, respectively) according to the National Earthquake Hazards Reduction Program (NEHRP) soil classification. Additionally, the southwestern and southeastern zones of the site area are characterized by maximum velocity values, relative high values of rock densities, rigidity or shear modulus “ μ ”, Standard Penetration Test (N-Value), ultimate bearing capacity and allowable bearing capacity, while the low values are observed through the northern and middle sectors across the area. This study an integral part of many works being carried out delineating the subsurface foundation structures around the solar plant and allows the most appropriate sites for constructing the renewable energy plants to be sited away from the highly hazards prone areas.
{"title":"Characteristics of the foundation rocks using geophysical techniques: A case study for the Egyptian solar plant site, Aswan, Egypt","authors":"Abdelnasser Mohamed","doi":"10.13168/agg.2022.0009","DOIUrl":"https://doi.org/10.13168/agg.2022.0009","url":null,"abstract":"The main target of the present study is to investigate the foundation layers and the subsurface structures in an Egyptian solar plant site using geophysical techniques including the seismic refraction and Multichannel Analysis of Surface Waves (MASW). The studied solar park is situated at about 40 km to the north of Aswan city on the Aswan-Cairo highway road and is classified as the largest solar plant in Africa and worldwide. Due to its location in the vicinity of the most prone earthquake area in Egypt (Aswan seismic zone); it is imperative to mitigate the earthquake hazard in this region. The geophysical results show that the subsurface foundation in this site is primarily composed of two layers. The upper one is loose and incompetent soil sediments that extend down to about 10 m depth with P-wave velocity ranging from 400 to 1000 m/s and shear-wave velocity ranging from 260 to 550 m/s. The deeper section is considered the main foundation layer with velocities ranging between 650 and 1900 m/s and from 350 to 950 m/s for P-wave and shear-wave, respectively. The average shear-wave velocities calculated for the topmost 30 m (Vs 30 ) vary almost between 319 and 834 m/s; thereby the studied site is primarily ranked into classes C&D (180-360 m/s & 360-760 m/s, respectively) according to the National Earthquake Hazards Reduction Program (NEHRP) soil classification. Additionally, the southwestern and southeastern zones of the site area are characterized by maximum velocity values, relative high values of rock densities, rigidity or shear modulus “ μ ”, Standard Penetration Test (N-Value), ultimate bearing capacity and allowable bearing capacity, while the low values are observed through the northern and middle sectors across the area. This study an integral part of many works being carried out delineating the subsurface foundation structures around the solar plant and allows the most appropriate sites for constructing the renewable energy plants to be sited away from the highly hazards prone areas.","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46000524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Geophysical approach for the ancient iron in Sungai Batu, Bujang Valley, Kedah, Malaysia","authors":"Naizatul Akma Mohd Mokhtar","doi":"10.13168/agg.2022.0008","DOIUrl":"https://doi.org/10.13168/agg.2022.0008","url":null,"abstract":"","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43456694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, a scheme based on fuzzy finite element method was provided for uncertainty quantification of liquefied saturated soil response under dynamic loading. In this respect, the coupled dynamic equations which are known as u-p equations were used, and instead of crisp values for input parameters, including permeability coefficient, specific mass of the soil, compressibility and shear modulus, their fuzzy numbers were used. At the end, displacements and pore water pressure created during earthquake were reported as fuzzy numbers. After verifying procedures of fuzzy analysis by experimental results from the centrifuge model test No. 1 from the VELACS project, several membership grades were considered. Firstly, the effect of fuzzification of each input soil parameter investigated individually, and then effect of considering all four input soil parameters as fuzzy numbers was analyzed by developed method. It was indicated that results of the analysis during the effective time of the earthquake were strongly influenced by the shear modulus and partially by compressibility modulus, and after this time, it was mainly affected by the permeability coefficient. Also considering uncertainty nature of specific mass of the soil had no significant effect on the results.
{"title":"Uncertainty quantification in the analysis of liquefied soil response through Fuzzy Finite Element method","authors":"F. Kalateh","doi":"10.13168/agg.2022.0007","DOIUrl":"https://doi.org/10.13168/agg.2022.0007","url":null,"abstract":"In the present study, a scheme based on fuzzy finite element method was provided for uncertainty quantification of liquefied saturated soil response under dynamic loading. In this respect, the coupled dynamic equations which are known as u-p equations were used, and instead of crisp values for input parameters, including permeability coefficient, specific mass of the soil, compressibility and shear modulus, their fuzzy numbers were used. At the end, displacements and pore water pressure created during earthquake were reported as fuzzy numbers. After verifying procedures of fuzzy analysis by experimental results from the centrifuge model test No. 1 from the VELACS project, several membership grades were considered. Firstly, the effect of fuzzification of each input soil parameter investigated individually, and then effect of considering all four input soil parameters as fuzzy numbers was analyzed by developed method. It was indicated that results of the analysis during the effective time of the earthquake were strongly influenced by the shear modulus and partially by compressibility modulus, and after this time, it was mainly affected by the permeability coefficient. Also considering uncertainty nature of specific mass of the soil had no significant effect on the results.","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44513360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of the work is to establish the correlation between the change of absolute rotation poles of major tectonic plates based on continuous GNSS stations data. The work investigates 2804 continuous GNSS stations located on Pacific, North American, Eurasian, African, Antarctic, Australian and South American plates during 2002-2021. The components of recent horizontal displacements of continuous GNSS stations have been determined and a map of their distribution pattern has been constructed. The absolute rotation pole in ITRF2014/IGS14 reference frame of the studied tectonic plates has been determined. The obtained values are in good agreement with modern plate models. The definition of average annual rotation poles has been developed and thei r analysis has been carried out to research the dynamics of their change in time. It has been established that the change in the average annual rotation poles of the North American, African and South American plates occurs synchronously, while their change is asynchronous to the Pacific plate. Simultaneous changes in the average annual rotation poles of Antarctic and African plates were have also been identified.
{"title":"Establishing the correlation between changes of absolute rotation poles of major tectonic plates based on continuous GNSS stations data","authors":"I. Savchyn","doi":"10.13168/agg.2022.0006","DOIUrl":"https://doi.org/10.13168/agg.2022.0006","url":null,"abstract":"The purpose of the work is to establish the correlation between the change of absolute rotation poles of major tectonic plates based on continuous GNSS stations data. The work investigates 2804 continuous GNSS stations located on Pacific, North American, Eurasian, African, Antarctic, Australian and South American plates during 2002-2021. The components of recent horizontal displacements of continuous GNSS stations have been determined and a map of their distribution pattern has been constructed. The absolute rotation pole in ITRF2014/IGS14 reference frame of the studied tectonic plates has been determined. The obtained values are in good agreement with modern plate models. The definition of average annual rotation poles has been developed and thei r analysis has been carried out to research the dynamics of their change in time. It has been established that the change in the average annual rotation poles of the North American, African and South American plates occurs synchronously, while their change is asynchronous to the Pacific plate. Simultaneous changes in the average annual rotation poles of Antarctic and African plates were have also been identified.","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43403767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Jahamah Platform is a part of a structural depression called the Sirt basin, located in the northern central part of Libya. The Jahamah Platform spans latitude 29.95 ° N to 30.55 ° N and longitudes 19.32 ° E to 19.77 ° E with an estimated area of about 2,187 km 2 . Libyan Petroleum Institute provided the data of aeromagnetic that was used in this study. The data was used to study the structure beneath the Jahamah Platform by using Oasis montaj software. Various filters from the software have been applied to enhance determining the fault system within the study area. An RTP filter was applied to the magnetic data to construct a reduction to the pole anomaly map. The subsurface structural elements underneath the study area were identified using Total horizontal derivative (THD), CET analysis, and Euler deconvolution. 2-D forward modelling of the area was constructed based on gravity data, and then the basement depth was estimated to range from km to 3.1 km based on the model. Based on the interpretation of the constructed maps, the area has a number of faults that trend in NE-SW, NNW-SSE, N-S and NW-SE and faults depth ranging between 790 m to 3102 m.
{"title":"Identifying fault system and basement depth using aeromagnetic data beneath the Jahamah Platform, NE Sirt Basin, Libya","authors":"Sufian Kahoul","doi":"10.13168/agg.2022.0005","DOIUrl":"https://doi.org/10.13168/agg.2022.0005","url":null,"abstract":"The Jahamah Platform is a part of a structural depression called the Sirt basin, located in the northern central part of Libya. The Jahamah Platform spans latitude 29.95 ° N to 30.55 ° N and longitudes 19.32 ° E to 19.77 ° E with an estimated area of about 2,187 km 2 . Libyan Petroleum Institute provided the data of aeromagnetic that was used in this study. The data was used to study the structure beneath the Jahamah Platform by using Oasis montaj software. Various filters from the software have been applied to enhance determining the fault system within the study area. An RTP filter was applied to the magnetic data to construct a reduction to the pole anomaly map. The subsurface structural elements underneath the study area were identified using Total horizontal derivative (THD), CET analysis, and Euler deconvolution. 2-D forward modelling of the area was constructed based on gravity data, and then the basement depth was estimated to range from km to 3.1 km based on the model. Based on the interpretation of the constructed maps, the area has a number of faults that trend in NE-SW, NNW-SSE, N-S and NW-SE and faults depth ranging between 790 m to 3102 m.","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41704760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The boundary conditions and loading ways of geostress field of oil and gas trap are the difficulties in the numerical simulation and geomechanical analysis. Owing to the limited data of geostress, unclear tectonic movement and complex geological structure, the stress field cannot be solved directly. Boundary load inversion is a very important method to analyze the stress field of rock mass. Based on the measured in-situ stress of S4 member in C41 fault block of Liangjialou oilfield, the boundary loads of the geological body stress field are inversely calculated. Meanwhile, the optimal boundary stress obtained by the inverse modeling is used to study the stress field near the fault. This method can overcome the shortcomings of common back analysis, such as boundary load adjustment method and regression method, and improve the calculation accuracy of stress field. The results show that the inversion method is simple, reliable, accurate and fast. The distribution of stress field can well reflect the in homogeneity of the magnitude and direction of the stress field near the fault. Therefore, this method has a certain application value in boundary load inversion, and the initial stress field distribution of faults provides a precondition for local stability.
{"title":"Finite element back analysis of geostress field in geological body of oil and gas trap","authors":"M. Xu","doi":"10.13168/agg.2022.0004","DOIUrl":"https://doi.org/10.13168/agg.2022.0004","url":null,"abstract":"The boundary conditions and loading ways of geostress field of oil and gas trap are the difficulties in the numerical simulation and geomechanical analysis. Owing to the limited data of geostress, unclear tectonic movement and complex geological structure, the stress field cannot be solved directly. Boundary load inversion is a very important method to analyze the stress field of rock mass. Based on the measured in-situ stress of S4 member in C41 fault block of Liangjialou oilfield, the boundary loads of the geological body stress field are inversely calculated. Meanwhile, the optimal boundary stress obtained by the inverse modeling is used to study the stress field near the fault. This method can overcome the shortcomings of common back analysis, such as boundary load adjustment method and regression method, and improve the calculation accuracy of stress field. The results show that the inversion method is simple, reliable, accurate and fast. The distribution of stress field can well reflect the in homogeneity of the magnitude and direction of the stress field near the fault. Therefore, this method has a certain application value in boundary load inversion, and the initial stress field distribution of faults provides a precondition for local stability.","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42592173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Assessment of pozzolanic material for manufacturing of Portland Pozzolana cement (PPC) by the comparison of Ordinary Portland cement (OPC)","authors":"A. Khan","doi":"10.13168/agg.2022.0002","DOIUrl":"https://doi.org/10.13168/agg.2022.0002","url":null,"abstract":"","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45716898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effect of crack characteristics on the mechanical properties and energy characteristics of coal-rock composite structure","authors":"Tan Li","doi":"10.13168/agg.2022.0003","DOIUrl":"https://doi.org/10.13168/agg.2022.0003","url":null,"abstract":"","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47598124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：