研制多分量地震监测系统AETA(acoustic&electro-magnetic testing all in one system)。在云南、四川、西藏、河北、北京、广东等地区的现场实验表明,该系统能够满足大区域密集布设中高灵敏度、低成本和易布设的需求。同时,若干点...研制多分量地震监测系统AETA(acoustic&electro-magnetic testing all in one system)。在云南、四川、西藏、河北、北京、广东等地区的现场实验表明,该系统能够满足大区域密集布设中高灵敏度、低成本和易布设的需求。同时,若干点的实验观测数据和均值、振铃率、峰值频率在一定程度上反映了映震效果。目前正在中国西南部、首都圈、台湾海峡等地区密集布设,系统地开展映震效果研究。展开更多
Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic se...Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic sensors have been established as a new and innovative measurement technology in very different fields, such as material science, civil engineering, light-weight structures, geotechnical areas as well as chemical and high-voltage substations. Very often, mechanical quantities such as deformation, strain or vibration are requested. However, measurement of chemical quantities in materials and structure components, such as pH value in steel reinforced concrete members also provides information about the integrity of concrete structures. A special fiber-optic chemical sensor for monitoring the alkaline state （pH value） of the cementitious matrix in steel-reinforced concrete structures with the purpose of early detection of corrosion-initiating factors is described. The paper presents the use of several fiber-optic sensor technologies in engineering. One example concerns the use of highly resolving concrete-embeddable fiber Fabry-Perot acoustic emission （AE） sensors for the assessment of the bearing behaviour of large concrete piles in existing foundations or during and after its installation. Another example concerns fiber Bragg grating （FBG） sensors attached to anchor steels （micro piles） to measure the strain distribution in loaded soil anchors. Polymer optical fibers （POF） can be -- because of their high elasticity and high ultimate strain - well integrated into textiles to monitor their deformation behaviour. Such ＂intelligent＂ textiles are capable of monitoring displacement of soil or slopes, critical mechanical deformation in geotechnical structures （dikes, dams, and embankments） as well as in masonry structures during and after earthquakes.展开更多
Interferometry Synthetic Aperture Radar(InSAR)provides unique capabilities to map regional/global topography and deformation of the Earth’s surface and has led to a broad spectrum of deformation monitoring applicatio...Interferometry Synthetic Aperture Radar(InSAR)provides unique capabilities to map regional/global topography and deformation of the Earth’s surface and has led to a broad spectrum of deformation monitoring applications.In order to adapt to various challenging monitoring environments,researchers have made tremendous innovations to deal with issues such as atmospheric and ionospheric effects,loss of coherence due to large displacements,geometric distortions and unwrapping errors.Owing to recent technical and methodological advances,the Earth’s surface deformation,ranging from earthquake ruptures,volcanic eruptions,landslides,glaciers,to groundwater storage variations,mining subsidence and infrastructure instability can now be mapped anywhere in the world at high spatial and temporal resolutions.This special issue received a set of contributions highlighting recent advances in methodologies and applications of InSAR to ground deformation monitoring.We aim to present overviews of both the state of the art of SAR/InSAR techniques and the next generation of applications across the broad range of deformation monitoring applications.展开更多
Reservoir-induced earthquakes related with the construction of the Three Gorges Project have attracted great concerns of the public. Since the first water impoundment on May 25, 2003, a number of earthquakes have occu...Reservoir-induced earthquakes related with the construction of the Three Gorges Project have attracted great concerns of the public. Since the first water impoundment on May 25, 2003, a number of earthquakes have occurred during the water storage stages, in which the largest was the Badong M5.1 earthquake on December 16, 2013. In this paper, the relationships between seismic activities, b value, seismic parameters, and reservoir water level fluctuations are studied. In addition, based on the digital seismic waveform data obtained since 2000, the focal depth changes and focal mechanism characteristics before and after the water impoundment are studied as well. These provide us important information to understand the earthquake mechanisms. The results show that these earthquakes are typical reservoir-induced earthquakes, which are closely related to water infiltration, pore pressure, and water level fluctuations.The majority of the micro and small earthquakes are caused by karst collapse, mine collapse, bank reformation, superficial unloading, and so on. The larger earthquakes are related to the fault structures to some extent. Due to the persistent effects of water impoundment on the seismic and geological environments around the reservoir and water infiltration into the rocks, the influences on the crustal deformation field, gravity field, seepage field, and fault medium-softening action may vary gradually from a higher strength to a weaker one. Therefore, it is possible that small earthquakes and few medium earthquakes(M≤5.5) will occur in the reservoir area in the future.展开更多
This paper investigated aqueous chemistry for two geothermal spring groups responsive and sensitive to flow fluctuations induced by earthquakes. Quake monitorings are favored for their being in residential areas with ...This paper investigated aqueous chemistry for two geothermal spring groups responsive and sensitive to flow fluctuations induced by earthquakes. Quake monitorings are favored for their being in residential areas with well-preserved natural flow systems in Xinyi City＇s Xijiang Hot Springs and Fengshun County＇s Shihu Hot Spring. The hot springs are typical in temperatures and flow rates in southern China＇s Guangdong Province. Physical and chemical conditions deep down in the heat sources are important constraints on earthquake, fluid flow, reactive solute transport and heat transfer, but remain challenging to address via field observations and numerical experiments. In this paper, we made daily and annual observations on flow rates, temperature, and/or aqueous chemistry. We employed strontium isotopes as tracers for the water sources, equilibrium phase diagram for K-feldspar and albite stability, and Na-K-Mg diagram for heat reservoir temperatures. The abundant sulfite content in Xi- jiang Hot Springs is discussed. Our main finding are that the deep fault springs are characterized by low reduction-oxidation potential at around -200- -150 mV and relatively large daily flow variations. The resuits provide scientific background features on the field sites regarding earthquake monitoring and predictions and geothermal reservoir.展开更多
This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in t...This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.展开更多
文摘研制多分量地震监测系统AETA(acoustic&electro-magnetic testing all in one system)。在云南、四川、西藏、河北、北京、广东等地区的现场实验表明,该系统能够满足大区域密集布设中高灵敏度、低成本和易布设的需求。同时,若干点的实验观测数据和均值、振铃率、峰值频率在一定程度上反映了映震效果。目前正在中国西南部、首都圈、台湾海峡等地区密集布设,系统地开展映震效果研究。
文摘Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic sensors have been established as a new and innovative measurement technology in very different fields, such as material science, civil engineering, light-weight structures, geotechnical areas as well as chemical and high-voltage substations. Very often, mechanical quantities such as deformation, strain or vibration are requested. However, measurement of chemical quantities in materials and structure components, such as pH value in steel reinforced concrete members also provides information about the integrity of concrete structures. A special fiber-optic chemical sensor for monitoring the alkaline state （pH value） of the cementitious matrix in steel-reinforced concrete structures with the purpose of early detection of corrosion-initiating factors is described. The paper presents the use of several fiber-optic sensor technologies in engineering. One example concerns the use of highly resolving concrete-embeddable fiber Fabry-Perot acoustic emission （AE） sensors for the assessment of the bearing behaviour of large concrete piles in existing foundations or during and after its installation. Another example concerns fiber Bragg grating （FBG） sensors attached to anchor steels （micro piles） to measure the strain distribution in loaded soil anchors. Polymer optical fibers （POF） can be -- because of their high elasticity and high ultimate strain - well integrated into textiles to monitor their deformation behaviour. Such ＂intelligent＂ textiles are capable of monitoring displacement of soil or slopes, critical mechanical deformation in geotechnical structures （dikes, dams, and embankments） as well as in masonry structures during and after earthquakes.
基金National Natural Science Foundation of China(Nos.41941019,42174018).
文摘Interferometry Synthetic Aperture Radar(InSAR)provides unique capabilities to map regional/global topography and deformation of the Earth’s surface and has led to a broad spectrum of deformation monitoring applications.In order to adapt to various challenging monitoring environments,researchers have made tremendous innovations to deal with issues such as atmospheric and ionospheric effects,loss of coherence due to large displacements,geometric distortions and unwrapping errors.Owing to recent technical and methodological advances,the Earth’s surface deformation,ranging from earthquake ruptures,volcanic eruptions,landslides,glaciers,to groundwater storage variations,mining subsidence and infrastructure instability can now be mapped anywhere in the world at high spatial and temporal resolutions.This special issue received a set of contributions highlighting recent advances in methodologies and applications of InSAR to ground deformation monitoring.We aim to present overviews of both the state of the art of SAR/InSAR techniques and the next generation of applications across the broad range of deformation monitoring applications.
基金supported by the National Natural Science Foundation of China (41572354)the Key Foundation of the Institute of Seismology (IS201616254)
文摘Reservoir-induced earthquakes related with the construction of the Three Gorges Project have attracted great concerns of the public. Since the first water impoundment on May 25, 2003, a number of earthquakes have occurred during the water storage stages, in which the largest was the Badong M5.1 earthquake on December 16, 2013. In this paper, the relationships between seismic activities, b value, seismic parameters, and reservoir water level fluctuations are studied. In addition, based on the digital seismic waveform data obtained since 2000, the focal depth changes and focal mechanism characteristics before and after the water impoundment are studied as well. These provide us important information to understand the earthquake mechanisms. The results show that these earthquakes are typical reservoir-induced earthquakes, which are closely related to water infiltration, pore pressure, and water level fluctuations.The majority of the micro and small earthquakes are caused by karst collapse, mine collapse, bank reformation, superficial unloading, and so on. The larger earthquakes are related to the fault structures to some extent. Due to the persistent effects of water impoundment on the seismic and geological environments around the reservoir and water infiltration into the rocks, the influences on the crustal deformation field, gravity field, seepage field, and fault medium-softening action may vary gradually from a higher strength to a weaker one. Therefore, it is possible that small earthquakes and few medium earthquakes(M≤5.5) will occur in the reservoir area in the future.
基金supported in part by 211 startup fund to the first author by China University of Geosciences (Wuhan)
文摘This paper investigated aqueous chemistry for two geothermal spring groups responsive and sensitive to flow fluctuations induced by earthquakes. Quake monitorings are favored for their being in residential areas with well-preserved natural flow systems in Xinyi City＇s Xijiang Hot Springs and Fengshun County＇s Shihu Hot Spring. The hot springs are typical in temperatures and flow rates in southern China＇s Guangdong Province. Physical and chemical conditions deep down in the heat sources are important constraints on earthquake, fluid flow, reactive solute transport and heat transfer, but remain challenging to address via field observations and numerical experiments. In this paper, we made daily and annual observations on flow rates, temperature, and/or aqueous chemistry. We employed strontium isotopes as tracers for the water sources, equilibrium phase diagram for K-feldspar and albite stability, and Na-K-Mg diagram for heat reservoir temperatures. The abundant sulfite content in Xi- jiang Hot Springs is discussed. Our main finding are that the deep fault springs are characterized by low reduction-oxidation potential at around -200- -150 mV and relatively large daily flow variations. The resuits provide scientific background features on the field sites regarding earthquake monitoring and predictions and geothermal reservoir.
文摘This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.
