In the last decade a New Geophysics has been proposed,whereby the crust and uppermost ~400 km of the mantle of the Earth are so pervaded by closely-spaced stress-aligned microcracks(intergranular films of hydrated mel...In the last decade a New Geophysics has been proposed,whereby the crust and uppermost ~400 km of the mantle of the Earth are so pervaded by closely-spaced stress-aligned microcracks(intergranular films of hydrated melt in the mantle) that in situ rocks verge on failure by fracturing,and hence are critical-systems that impose a range of fundamentally-new properties on conventional sub-critical geophysics.Enough of these new properties have been observed to confirm that New Geophysics is a new understanding of fluid/rock deformation with important implications and applications.Evidence supporting New Geophysics has been published in a wide variety of publications.Here,for clarification,we summarise in one document the evidence supporting New Geophysics.展开更多
Geophysical methods have been applied to a wide range of hydrogeological problems. With improvement in geophysical inversion algorithms and measurement tools, significant achievements have been made in the characteriz...Geophysical methods have been applied to a wide range of hydrogeological problems. With improvement in geophysical inversion algorithms and measurement tools, significant achievements have been made in the characterization of subsurface architecture, time-lapse monitoring of hydrogeological process and contaminant plumes delineation. In this paper, we summarize the geophysical methods that are most widely used in hydrogeology including Electrical Resistivity Tomography(ERT), Induced Polarization(IP), Ground Penetrating Radar(GPR) and Electromagnetic Induction(EMI). Three examples including lab and field works are used to demonstrate current application of geophysical methods for characterizing subsurface architecture and contaminant plumes. Though great progress has been made in hydrogeohysics over the last few decades at home and abroad, challenges still remain in practical applications. More recently, hydrogeophysics continues to develop in the areas of establishment of hydrogeophysical models, large-scale architecture characterization, uncertainty analysis, biogeochemical process monitoring and ecosystem science.展开更多
Magma is transported in brittle rock by diking.Diking plays a key role in tectonic phenomena such as continental rifting and plate divergence at mid-ocean ridges.In spite of the importance of understanding how magma
"Beyond 100: The next century in Earth and Space Science"The 27th IUGG General Assembly will be held July 8-18,2019 at the Palais des Congrès in Montréal,Québec,Canada.This is a special opport..."Beyond 100: The next century in Earth and Space Science"The 27th IUGG General Assembly will be held July 8-18,2019 at the Palais des Congrès in Montréal,Québec,Canada.This is a special opportunity for participants from Canada and from around the world to come together and share their science and culture.2019 marks the 100th anniversary of IUGG;we will look back on the accomplishments of the previous century of Earth and space science research,and forward to the next century of scientific advancement.Join us for a host of scientific activities,including special public lectures,keynote Union lectures and a wide variety of themed sessions.展开更多
A selection of a number of geophysical methods to solve different geological, geodynamical, environmental, archaeological and other problems usually has no theoretical substantiation. The solution to this “four color...A selection of a number of geophysical methods to solve different geological, geodynamical, environmental, archaeological and other problems usually has no theoretical substantiation. The solution to this “four color” mathematical problem is able to assume that two independent geophysical methods are sufficient theoretically to characterize the geological-geophysical peculiarities of the area under study.展开更多
The determination and monitoring of aquifer formations on the eastern border of Moroccan Gharb basin are very difficult because of their spatial and temporal variation. To delimit these formations, a geophysical surve...The determination and monitoring of aquifer formations on the eastern border of Moroccan Gharb basin are very difficult because of their spatial and temporal variation. To delimit these formations, a geophysical survey of 52 geoelectric soundings was performed with a mesh of 500 m and electrodes distance between 1000 m and 3000 m. Geoelectric sections and resistivity maps show a horst and graben structure. The correlation of existing oil drillings shows that the Jurassic and Neogene formations are both affected by normal faults causing Jurassic deposits collapse with local thickening of the Miocene deposits, and reverse faults delimiting tectonic slices due to tension caused by prerifaine nappe advance. This fact confirms the generated structure by the resistivity method. The isobath map of resistant formations's roof show average depths extending from 400 to 800 m for calcareous sandstone that are potential aquifers while oil drillings indicate over 1000 m depths.展开更多
On the basis of the characteristics of geology and geophysics in North China, three types of lithosphere, namely, the cratonic, the orogenic and the rift lithospheres can be classified. In terms of petrological method...On the basis of the characteristics of geology and geophysics in North China, three types of lithosphere, namely, the cratonic, the orogenic and the rift lithospheres can be classified. In terms of petrological method (based on the information from Precambrian rock assemblages, igneous activities, deep-seated enclaves, etc.) and the relationship between seismic velocity and rock compositions, the crust-mantle petrological and chemical structure models can be set up. Researching results indicate that the geology and geophysics of North China platform bears the similar characteristics in comparison with those of the global typical cratons. The Eerduosi(Ordos) block located in the west of the North China Platform is a remnant of cratonic lithosphere after the North China platform had undergone “activation” in Mesozoic and “reconstruction” in Cenozoic times. The continental crust consists mainly of TTG rock assemblage while the subcontinental lithosphere mantle mainly consists of strongly depleted harzburgite. The craton was finally formed in late Archaean and early Proterozoic, and has been kept in stability up to present; its crustal-mantle petrological structures of lithosphere can be set up as a reference for the study of North China craton and even Sino-Korean craton. In the Mesozoic period, the middle and east areas of North China platform were activated in the Yanshanian orogenic process, the continental crust was reformed by material and heat-transfer of convective mantle and the original crustal TTG component was reconstructed to be granitic crust, and the subcontinental lithosphere man- tle was replaced by the Yanshanian harzburgite-lherzolite. The Yanshan-Taihang Mountains were the remnants of orogenic lithosphere after the rifting in eastern North China in Cenozoic. The present thickness of continental crust and lithosphere in the Yanshan-Taihang Mountains is not equal to their thickness during the Yanshanian orogenic movement because they had undergone the crustal extensional thinning in Cenozoic, however, the material and structure of lithosphere mantle-crust were formed during the Yanshanian orogenic movement. In the Cenozoic Period, the rift-type lithosphere, as represented by the North China plain, was formed by the continental rifting occurring in the eastern part of North China. The continental granitic crust, which had been “acidified” at the Yanshanian period, was basified again by the eruption of basalt magma along the continental rifting, and the subcontinental lithosphere mantle formed in Yanshanian was de- stroyed and replaced by the Himalayan mantle which consists mainly of lherzolite. Both the crust and the lithospheric mantle in the rift have undergone extensional thinning and thermal erosion at lithospheric-scale, the material and structure of the present mantle-crust lithosphere, attained from geophysical exploration, was formed in Cenozoic. The formation and evolution of litho- sphere in North China indicate that the material and heat transferred by convective mantle into the continental crust was the key for different types of lithosphere forming, and the crust-mantle petrologic structure was the records of lithosphere evolution, and it was the integrated results of the deep processes of the China continental dynamic system and the Pacific Plate subduction located in the eastern margin of the North China platform in Mesozoic-Cenozoic time.展开更多
Comprehensive investigations along the Gyirong-Lugu-Sangehu geophysical profile in the western Xizang Plateau are presented. Analysis and interpretation of the lithospheric structure resulted in setting up of the geop...Comprehensive investigations along the Gyirong-Lugu-Sangehu geophysical profile in the western Xizang Plateau are presented. Analysis and interpretation of the lithospheric structure resulted in setting up of the geophysical methods and marks for the division of tectonic units in the lithospheric structure. Comprehensive geophysical survey in the remote west of Xizang is reported and some reliable geophysical evidence for deep structure division in the study region is provided. These lay a solid basis for probing into the mechanism of the Xizang Plateau uplift and geodynamics.展开更多
Ground penetrating radar(GPR)investigations have the potential to non-destructively detect buried or hidden targets and are therefore often used in forensic research.This study presents a particular application of GPR...Ground penetrating radar(GPR)investigations have the potential to non-destructively detect buried or hidden targets and are therefore often used in forensic research.This study presents a particular application of GPR methods to search for a missing person in a specific subsurface environment:a natural cave.The search for missing people in Italy is a problematic and delicate task that needs improvement.Results of this study highlight not only the ability to detect both hollow and forensic targets,but also precisely locate and define their geometries.Moreover,GPR findings efficiently focus archaeological excavation and body recovery in an exact area and help to minimise time digging in erroneous places.展开更多
Groundwater is an important source of drinking water.Groundwater pollution severely endangers drinking water safety and sustainable social development.In the case of groundwater pollution,the top priority is to identi...Groundwater is an important source of drinking water.Groundwater pollution severely endangers drinking water safety and sustainable social development.In the case of groundwater pollution,the top priority is to identify pollution sources,and accurate information on pollution sources is the premise of efficient remediation.Then,an appropriate pollution remediation scheme should be developed according to information on pollution sources,site conditions,and economic costs.The methods for identifying pollution sources mainly include geophysical exploration,geochemistry,isotopic tracing,and numerical modeling.Among these identification methods,only the numerical modeling can recognize various information on pollution sources,while other methods can only identify a certain aspect of pollution sources.The remediation technologies of groundwater can be divided into in-situ and ex-situ remediation technologies according to the remediation location.The in-situ remediation technologies enjoy low costs and a wide remediation range,but their remediation performance is prone to be affected by environmental conditions and cause secondary pollution.The ex-situ remediation technologies boast high remediation efficiency,high processing capacity,and high treatment concentration but suffer high costs.Different methods for pollution source identification and remediation technologies are applicable to different conditions.To achieve the expected identification and remediation results,it is feasible to combine several methods and technologies according to the actual hydrogeological conditions of contaminated sites and the nature of pollutants.Additionally,detailed knowledge about the hydrogeological conditions and stratigraphic structure of the contaminated site is the basis of all work regardless of the adopted identification methods or remediation technologies.展开更多
Aspan of twenty-five years,for a company,constitutes a engthy and eventful journey.Twenty-five years ago,a group of oil professionals from the Bureau of Geophysical Prospecting INC (hereinafter referred to as BGP),set...Aspan of twenty-five years,for a company,constitutes a engthy and eventful journey.Twenty-five years ago,a group of oil professionals from the Bureau of Geophysical Prospecting INC (hereinafter referred to as BGP),set foot on the land of Nigeria and embarked on a legendary journey.This is a narrative of resilience,commitment,and heartfelt passion,an inspiring saga that touches the soul.展开更多
The dual transmitter implements the equivalent anti-magnetic flux transient electromagnetic method, which can effectively reduce the scope of the transient electromagnetic detection blind area. However, this method is...The dual transmitter implements the equivalent anti-magnetic flux transient electromagnetic method, which can effectively reduce the scope of the transient electromagnetic detection blind area. However, this method is rarely reported in the detection of pipelines in urban geophysical exploration and the application of coal mines. Based on this, this paper realizes the equivalent anti-magnetic flux transient electromagnetic method based on the dual launcher. The suppression effect of this method on the blind area is analyzed by physical simulation. And the detection experiment of underground pipelines is carried out outdoors. The results show that the dual launcher can significantly reduce the turn-off time, thereby effectively reducing the impact of the blind area on the detection results, and the pipeline detection results verify the device’s effectiveness. Finally, based on the ground experimental results, the application prospect of mine advanced detection is discussed. Compared with other detection fields, the formation of blind areas is mainly caused by the equipment. If the dual launcher can be used to reduce the blind area, the accuracy of advanced detection can be improved more effectively. The above research results are of great significance for improving the detection accuracy of the underground transient electromagnetic method.展开更多
Computational geophysics is vitally important for improving our understanding ofthe Earth and Earth processes;however solutions to most problems in computationalgeophysics have been unapproachable due to limited compu...Computational geophysics is vitally important for improving our understanding ofthe Earth and Earth processes;however solutions to most problems in computationalgeophysics have been unapproachable due to limited computing capacity. With increasingcomputer speed, memory, storage capacity, and input/output capability, solvingthese problems is becoming feasible. Computational geophysics can include not onlyforward modeling to predict what will happen in a given situation but inverse modelingor inversion, in which data are interpreted in terms of a model. Such inversion canbe even more computationally intensive than forward modeling as it can require severaliterations of forward modeling. This Special Issue contains 13 papers and encompassesseveral different and important computational geophysical problems, includingseismic-wave modeling using different methods, electromagnetic modeling/inversion,and tsunami simulation.展开更多
文摘In the last decade a New Geophysics has been proposed,whereby the crust and uppermost ~400 km of the mantle of the Earth are so pervaded by closely-spaced stress-aligned microcracks(intergranular films of hydrated melt in the mantle) that in situ rocks verge on failure by fracturing,and hence are critical-systems that impose a range of fundamentally-new properties on conventional sub-critical geophysics.Enough of these new properties have been observed to confirm that New Geophysics is a new understanding of fluid/rock deformation with important implications and applications.Evidence supporting New Geophysics has been published in a wide variety of publications.Here,for clarification,we summarise in one document the evidence supporting New Geophysics.
基金funded by the National Natural Science Fund of China (NSFC)-Xinjiang No.U1503282the NSFC No.41030746,41672229 and 41172206
文摘Geophysical methods have been applied to a wide range of hydrogeological problems. With improvement in geophysical inversion algorithms and measurement tools, significant achievements have been made in the characterization of subsurface architecture, time-lapse monitoring of hydrogeological process and contaminant plumes delineation. In this paper, we summarize the geophysical methods that are most widely used in hydrogeology including Electrical Resistivity Tomography(ERT), Induced Polarization(IP), Ground Penetrating Radar(GPR) and Electromagnetic Induction(EMI). Three examples including lab and field works are used to demonstrate current application of geophysical methods for characterizing subsurface architecture and contaminant plumes. Though great progress has been made in hydrogeohysics over the last few decades at home and abroad, challenges still remain in practical applications. More recently, hydrogeophysics continues to develop in the areas of establishment of hydrogeophysical models, large-scale architecture characterization, uncertainty analysis, biogeochemical process monitoring and ecosystem science.
文摘Magma is transported in brittle rock by diking.Diking plays a key role in tectonic phenomena such as continental rifting and plate divergence at mid-ocean ridges.In spite of the importance of understanding how magma
文摘"Beyond 100: The next century in Earth and Space Science"The 27th IUGG General Assembly will be held July 8-18,2019 at the Palais des Congrès in Montréal,Québec,Canada.This is a special opportunity for participants from Canada and from around the world to come together and share their science and culture.2019 marks the 100th anniversary of IUGG;we will look back on the accomplishments of the previous century of Earth and space science research,and forward to the next century of scientific advancement.Join us for a host of scientific activities,including special public lectures,keynote Union lectures and a wide variety of themed sessions.
文摘A selection of a number of geophysical methods to solve different geological, geodynamical, environmental, archaeological and other problems usually has no theoretical substantiation. The solution to this “four color” mathematical problem is able to assume that two independent geophysical methods are sufficient theoretically to characterize the geological-geophysical peculiarities of the area under study.
文摘The determination and monitoring of aquifer formations on the eastern border of Moroccan Gharb basin are very difficult because of their spatial and temporal variation. To delimit these formations, a geophysical survey of 52 geoelectric soundings was performed with a mesh of 500 m and electrodes distance between 1000 m and 3000 m. Geoelectric sections and resistivity maps show a horst and graben structure. The correlation of existing oil drillings shows that the Jurassic and Neogene formations are both affected by normal faults causing Jurassic deposits collapse with local thickening of the Miocene deposits, and reverse faults delimiting tectonic slices due to tension caused by prerifaine nappe advance. This fact confirms the generated structure by the resistivity method. The isobath map of resistant formations's roof show average depths extending from 400 to 800 m for calcareous sandstone that are potential aquifers while oil drillings indicate over 1000 m depths.
基金supported by the Special Program of the Ministry of Land and Resources of China(Grant Nos.200010103 and 20001010202)the Researching Project of Deep-Level Substance’s Model of China Lithosphere,the Key Laboratory of Lithosphere Tectonics and Explorat ion,China Univers ity of Geosciences,Ministry of Education of China(Grant Nos.2003009 and 2003010)+1 种基金the Project of Key Problem on the Granite Geology in China,China Geological Survey(Grant No.200113900018)the National Natural Science Foundation of China(Grant No.402344048).
文摘On the basis of the characteristics of geology and geophysics in North China, three types of lithosphere, namely, the cratonic, the orogenic and the rift lithospheres can be classified. In terms of petrological method (based on the information from Precambrian rock assemblages, igneous activities, deep-seated enclaves, etc.) and the relationship between seismic velocity and rock compositions, the crust-mantle petrological and chemical structure models can be set up. Researching results indicate that the geology and geophysics of North China platform bears the similar characteristics in comparison with those of the global typical cratons. The Eerduosi(Ordos) block located in the west of the North China Platform is a remnant of cratonic lithosphere after the North China platform had undergone “activation” in Mesozoic and “reconstruction” in Cenozoic times. The continental crust consists mainly of TTG rock assemblage while the subcontinental lithosphere mantle mainly consists of strongly depleted harzburgite. The craton was finally formed in late Archaean and early Proterozoic, and has been kept in stability up to present; its crustal-mantle petrological structures of lithosphere can be set up as a reference for the study of North China craton and even Sino-Korean craton. In the Mesozoic period, the middle and east areas of North China platform were activated in the Yanshanian orogenic process, the continental crust was reformed by material and heat-transfer of convective mantle and the original crustal TTG component was reconstructed to be granitic crust, and the subcontinental lithosphere man- tle was replaced by the Yanshanian harzburgite-lherzolite. The Yanshan-Taihang Mountains were the remnants of orogenic lithosphere after the rifting in eastern North China in Cenozoic. The present thickness of continental crust and lithosphere in the Yanshan-Taihang Mountains is not equal to their thickness during the Yanshanian orogenic movement because they had undergone the crustal extensional thinning in Cenozoic, however, the material and structure of lithosphere mantle-crust were formed during the Yanshanian orogenic movement. In the Cenozoic Period, the rift-type lithosphere, as represented by the North China plain, was formed by the continental rifting occurring in the eastern part of North China. The continental granitic crust, which had been “acidified” at the Yanshanian period, was basified again by the eruption of basalt magma along the continental rifting, and the subcontinental lithosphere mantle formed in Yanshanian was de- stroyed and replaced by the Himalayan mantle which consists mainly of lherzolite. Both the crust and the lithospheric mantle in the rift have undergone extensional thinning and thermal erosion at lithospheric-scale, the material and structure of the present mantle-crust lithosphere, attained from geophysical exploration, was formed in Cenozoic. The formation and evolution of litho- sphere in North China indicate that the material and heat transferred by convective mantle into the continental crust was the key for different types of lithosphere forming, and the crust-mantle petrologic structure was the records of lithosphere evolution, and it was the integrated results of the deep processes of the China continental dynamic system and the Pacific Plate subduction located in the eastern margin of the North China platform in Mesozoic-Cenozoic time.
基金Project supported by National "Eighth Five-Year" Climbing Project.
文摘Comprehensive investigations along the Gyirong-Lugu-Sangehu geophysical profile in the western Xizang Plateau are presented. Analysis and interpretation of the lithospheric structure resulted in setting up of the geophysical methods and marks for the division of tectonic units in the lithospheric structure. Comprehensive geophysical survey in the remote west of Xizang is reported and some reliable geophysical evidence for deep structure division in the study region is provided. These lay a solid basis for probing into the mechanism of the Xizang Plateau uplift and geodynamics.
文摘Ground penetrating radar(GPR)investigations have the potential to non-destructively detect buried or hidden targets and are therefore often used in forensic research.This study presents a particular application of GPR methods to search for a missing person in a specific subsurface environment:a natural cave.The search for missing people in Italy is a problematic and delicate task that needs improvement.Results of this study highlight not only the ability to detect both hollow and forensic targets,but also precisely locate and define their geometries.Moreover,GPR findings efficiently focus archaeological excavation and body recovery in an exact area and help to minimise time digging in erroneous places.
基金funded by the National Natural Science Foundation of China(41907175)the Open Fund of Key Laboratory(WSRCR-2023-01)the project of the China Geological Survey(DD20230459).
文摘Groundwater is an important source of drinking water.Groundwater pollution severely endangers drinking water safety and sustainable social development.In the case of groundwater pollution,the top priority is to identify pollution sources,and accurate information on pollution sources is the premise of efficient remediation.Then,an appropriate pollution remediation scheme should be developed according to information on pollution sources,site conditions,and economic costs.The methods for identifying pollution sources mainly include geophysical exploration,geochemistry,isotopic tracing,and numerical modeling.Among these identification methods,only the numerical modeling can recognize various information on pollution sources,while other methods can only identify a certain aspect of pollution sources.The remediation technologies of groundwater can be divided into in-situ and ex-situ remediation technologies according to the remediation location.The in-situ remediation technologies enjoy low costs and a wide remediation range,but their remediation performance is prone to be affected by environmental conditions and cause secondary pollution.The ex-situ remediation technologies boast high remediation efficiency,high processing capacity,and high treatment concentration but suffer high costs.Different methods for pollution source identification and remediation technologies are applicable to different conditions.To achieve the expected identification and remediation results,it is feasible to combine several methods and technologies according to the actual hydrogeological conditions of contaminated sites and the nature of pollutants.Additionally,detailed knowledge about the hydrogeological conditions and stratigraphic structure of the contaminated site is the basis of all work regardless of the adopted identification methods or remediation technologies.
文摘Aspan of twenty-five years,for a company,constitutes a engthy and eventful journey.Twenty-five years ago,a group of oil professionals from the Bureau of Geophysical Prospecting INC (hereinafter referred to as BGP),set foot on the land of Nigeria and embarked on a legendary journey.This is a narrative of resilience,commitment,and heartfelt passion,an inspiring saga that touches the soul.
文摘The dual transmitter implements the equivalent anti-magnetic flux transient electromagnetic method, which can effectively reduce the scope of the transient electromagnetic detection blind area. However, this method is rarely reported in the detection of pipelines in urban geophysical exploration and the application of coal mines. Based on this, this paper realizes the equivalent anti-magnetic flux transient electromagnetic method based on the dual launcher. The suppression effect of this method on the blind area is analyzed by physical simulation. And the detection experiment of underground pipelines is carried out outdoors. The results show that the dual launcher can significantly reduce the turn-off time, thereby effectively reducing the impact of the blind area on the detection results, and the pipeline detection results verify the device’s effectiveness. Finally, based on the ground experimental results, the application prospect of mine advanced detection is discussed. Compared with other detection fields, the formation of blind areas is mainly caused by the equipment. If the dual launcher can be used to reduce the blind area, the accuracy of advanced detection can be improved more effectively. The above research results are of great significance for improving the detection accuracy of the underground transient electromagnetic method.
文摘Computational geophysics is vitally important for improving our understanding ofthe Earth and Earth processes;however solutions to most problems in computationalgeophysics have been unapproachable due to limited computing capacity. With increasingcomputer speed, memory, storage capacity, and input/output capability, solvingthese problems is becoming feasible. Computational geophysics can include not onlyforward modeling to predict what will happen in a given situation but inverse modelingor inversion, in which data are interpreted in terms of a model. Such inversion canbe even more computationally intensive than forward modeling as it can require severaliterations of forward modeling. This Special Issue contains 13 papers and encompassesseveral different and important computational geophysical problems, includingseismic-wave modeling using different methods, electromagnetic modeling/inversion,and tsunami simulation.
