This article analyzes the relationship between the water level and the water-tube tilting in Shuangyang lake,based on the differential deformation features reflected by the NS and EW components of the water-tube tiltm...This article analyzes the relationship between the water level and the water-tube tilting in Shuangyang lake,based on the differential deformation features reflected by the NS and EW components of the water-tube tiltmeter.The results show a good spatiotemporal consistency between the variation of water level and the NS tilt component,which is considered to be affected by the magnitude and duration of the water level variation in Shuangyang Lake.The article uses Landsat remote sensing image data to extract the water boundary of Shuan-gyang Lake,and takes advantage of the finite element numerical simulation method to build three-dimensional models for different geological structural conditions of the Shuangyang seismostation.The simulation results show that when the underground medium is granite,the effect of water level variation on the vertical displacement of the surface is non-directional.With a 50-m soil layer in Model 2,the simulated NS tilt variation is equivalent to the actual observed water-tube tiltmeter NS component when the water level variation is 0.44 m and 0.8m.When the variation of water level reaches 2.0m,the simulation result of the NS component is 79.6 ms,which is slightly larger than the observed result of 60.32 ms.However,the simulation results show that the variation of the EW component is significantly smaller than that of the NS one.Due to the fact that the Shuan-gyang lake is long in the NS direction and short in the EW direction,the existence of the soil layer tends to generate ground deformation along the NS direction in the vicinity of the lake after the increase of water level,thereby resulting in the difference of the ground deformation in the two directions.展开更多
We report here the observation result of joint observation of long period tremor signals with broadband seismome-ter,tiltmeter and gravimeter at the HUST(Huazhong University of Science and Technology)station.The obser...We report here the observation result of joint observation of long period tremor signals with broadband seismome-ter,tiltmeter and gravimeter at the HUST(Huazhong University of Science and Technology)station.The observed data were compared and analyzed.Since 2005,the several tens of abnormal tremor signals which are weak,com-plex and duration of 2 to 3 days have been synchronously recorded by the different instruments.The tremor signals have the periodic domain in the range of 3 to 5 minutes,20 to 30 minutes and even more than 1 hour.The observa-tion shows such tremors are a physical existence.The analysis indicates that a part of the tremors caused by the typhoon from the western Pacific Ocean.These tremors have a close relationship with wind velocity of typhoon and distance between the typhoon center and the station.Except these,the cause of others is still unclear.展开更多
The observatory network of the Crustal Deformation China Seismological Bureau was equipped with vertical pendulum tiltmeter,borehole tiltmeter,tunnel extension meters,multi-component borehole strainmeter,body strainme...The observatory network of the Crustal Deformation China Seismological Bureau was equipped with vertical pendulum tiltmeter,borehole tiltmeter,tunnel extension meters,multi-component borehole strainmeter,body strainmeter and other tilt and strain observation instruments.All of these instruments have recorded the Earth’s free oscillation excited by the Japan Mw9.0 Earthquake.By analyzing those observations,all of the spheroidal oscillation modes(0S3-0S30)and toroidal oscillation modes(0T3-0T20)excited by the Japan Mw9.0 Earthquake were detected in this paper.In addition,comparing the different observation results which obtained by those instruments,we revealed their capacity to observe different kinds of oscillation and different frequency band modes,and analyzed report the reason.We found that the body strainmeter and the vertical pendulum tiltmeter have better observing results for spheroidal oscillation.Because of high noise in low frequency band,the borehole tiltmeter cannot observe the low-order spheroidal oscillation.In terms of observing the toroidal oscillation,the multi-component borehole strainmeter got a best result.The vertical pendulum tiltmeter observes a few toroidal oscillation modes,and the tunnel extension meters can only observe some low-order modes.展开更多
Vertical pendulum(VP) tiltmeter is a kind of earthquake precursor observation equipment,which is used to record the interaction force associated with astronomical tidal tilts caused. Currently, VP broadband tiltmeter ...Vertical pendulum(VP) tiltmeter is a kind of earthquake precursor observation equipment,which is used to record the interaction force associated with astronomical tidal tilts caused. Currently, VP broadband tiltmeter and vertical sensor(VS) vertical pendulum tiltmeter are primarily used. In this paper, we compare the two different instruments by using four aspectsdmechanical structure, circuitry, zeroing, and bandwidthdbased on their working principles and applications. We conclude that VP broadband tiltmeter is more superior compared with VS vertical pendulum tiltmeter because of its higher bandwidth and degree of automation.展开更多
By using the observation data of the vertical pendulum tiltmeter in China,the influence of different sampling rates on the results of power spectral density is studied,and the background noise level of the seismic fre...By using the observation data of the vertical pendulum tiltmeter in China,the influence of different sampling rates on the results of power spectral density is studied,and the background noise level of the seismic frequency band(200-600 s)of different stations and different types of instruments is emphatically analyzed.The conclusions are as follows:1.The results of both single station and national statistics show that the noise levels of the two types of pendulum tiltmeter equal in the seismic frequency band;2.There is no obvious regularity in the regional distribution,due to the influence of ocean and active tectonic movement,the noise levels of some stations in coastal areas are relatively high;3,The curves of high noise level instrument are generally not smooth and burr-prone.Except for some stations affected by the ocean,they are mostly caused by the observation environment or the instrument itself.展开更多
Borehole inclinometers are important observation instruments used to measure ground tilt movement and monitor crustal deformation of solid tides and geological landslide disasters.They are widely used in oil explorati...Borehole inclinometers are important observation instruments used to measure ground tilt movement and monitor crustal deformation of solid tides and geological landslide disasters.They are widely used in oil exploration,mineral resource drilling,well logging,exploration and other fields.There is potential for development of rock stress strain monitoring tools.Many types of tiltmeters have been installed,such as SQ-7,FSQ,VS and JB.However,these tiltmeters are generally installed in a deep cave to avoid the interference of temperature,humidity,and human activities.With the urbanization of human society,suitable installation locations are difficult to find.To solve the problem,a two-component borehole tiltmeter,named the CBT-type tiltmeter,is proposed in this paper.It can be installed in a borehole less than500 m deep to eliminate environmental influences.The tiltmeter is composed of two sophisticated gravitational swing and two capacitive transducers.From preliminary theory and experiment analysis,its linear correlation coefficient is higher than 0.99,its co-seismic response is rapid and its noise level is up to 10 4arc seconds in practice.展开更多
基金sponsored by National Key Research and Development Program of China(2018YFC0807000)The Spark Program of Earthquake Technology of CEA(XH20070Y)The Earthquake Tracking Task of CEA(2021010221).
文摘This article analyzes the relationship between the water level and the water-tube tilting in Shuangyang lake,based on the differential deformation features reflected by the NS and EW components of the water-tube tiltmeter.The results show a good spatiotemporal consistency between the variation of water level and the NS tilt component,which is considered to be affected by the magnitude and duration of the water level variation in Shuangyang Lake.The article uses Landsat remote sensing image data to extract the water boundary of Shuan-gyang Lake,and takes advantage of the finite element numerical simulation method to build three-dimensional models for different geological structural conditions of the Shuangyang seismostation.The simulation results show that when the underground medium is granite,the effect of water level variation on the vertical displacement of the surface is non-directional.With a 50-m soil layer in Model 2,the simulated NS tilt variation is equivalent to the actual observed water-tube tiltmeter NS component when the water level variation is 0.44 m and 0.8m.When the variation of water level reaches 2.0m,the simulation result of the NS component is 79.6 ms,which is slightly larger than the observed result of 60.32 ms.However,the simulation results show that the variation of the EW component is significantly smaller than that of the NS one.Due to the fact that the Shuan-gyang lake is long in the NS direction and short in the EW direction,the existence of the soil layer tends to generate ground deformation along the NS direction in the vicinity of the lake after the increase of water level,thereby resulting in the difference of the ground deformation in the two directions.
文摘We report here the observation result of joint observation of long period tremor signals with broadband seismome-ter,tiltmeter and gravimeter at the HUST(Huazhong University of Science and Technology)station.The observed data were compared and analyzed.Since 2005,the several tens of abnormal tremor signals which are weak,com-plex and duration of 2 to 3 days have been synchronously recorded by the different instruments.The tremor signals have the periodic domain in the range of 3 to 5 minutes,20 to 30 minutes and even more than 1 hour.The observa-tion shows such tremors are a physical existence.The analysis indicates that a part of the tremors caused by the typhoon from the western Pacific Ocean.These tremors have a close relationship with wind velocity of typhoon and distance between the typhoon center and the station.Except these,the cause of others is still unclear.
基金supported by China seismological bureau special scientific research(17A18ZX085)
文摘The observatory network of the Crustal Deformation China Seismological Bureau was equipped with vertical pendulum tiltmeter,borehole tiltmeter,tunnel extension meters,multi-component borehole strainmeter,body strainmeter and other tilt and strain observation instruments.All of these instruments have recorded the Earth’s free oscillation excited by the Japan Mw9.0 Earthquake.By analyzing those observations,all of the spheroidal oscillation modes(0S3-0S30)and toroidal oscillation modes(0T3-0T20)excited by the Japan Mw9.0 Earthquake were detected in this paper.In addition,comparing the different observation results which obtained by those instruments,we revealed their capacity to observe different kinds of oscillation and different frequency band modes,and analyzed report the reason.We found that the body strainmeter and the vertical pendulum tiltmeter have better observing results for spheroidal oscillation.Because of high noise in low frequency band,the borehole tiltmeter cannot observe the low-order spheroidal oscillation.In terms of observing the toroidal oscillation,the multi-component borehole strainmeter got a best result.The vertical pendulum tiltmeter observes a few toroidal oscillation modes,and the tunnel extension meters can only observe some low-order modes.
基金supported by the Science for Earthquake Resilience of China Earthquake Administration (XH15030)the Special Scientific Fund of China Earthquake Administration (2012419002)
文摘Vertical pendulum(VP) tiltmeter is a kind of earthquake precursor observation equipment,which is used to record the interaction force associated with astronomical tidal tilts caused. Currently, VP broadband tiltmeter and vertical sensor(VS) vertical pendulum tiltmeter are primarily used. In this paper, we compare the two different instruments by using four aspectsdmechanical structure, circuitry, zeroing, and bandwidthdbased on their working principles and applications. We conclude that VP broadband tiltmeter is more superior compared with VS vertical pendulum tiltmeter because of its higher bandwidth and degree of automation.
基金supported by Scientific Research Fund of Institute of Seismology and Institute of Crustal Dynamics,CEA(IS201216018)supported by Combination Project with Monitoring,Prediction and Scientific Research of Earthquake Technology,CEA(3JH-201902009)Scientific Research Fund of Institute of Seismology and Institute of Crustal Dynamics,CEA(IS201216018).
文摘By using the observation data of the vertical pendulum tiltmeter in China,the influence of different sampling rates on the results of power spectral density is studied,and the background noise level of the seismic frequency band(200-600 s)of different stations and different types of instruments is emphatically analyzed.The conclusions are as follows:1.The results of both single station and national statistics show that the noise levels of the two types of pendulum tiltmeter equal in the seismic frequency band;2.There is no obvious regularity in the regional distribution,due to the influence of ocean and active tectonic movement,the noise levels of some stations in coastal areas are relatively high;3,The curves of high noise level instrument are generally not smooth and burr-prone.Except for some stations affected by the ocean,they are mostly caused by the observation environment or the instrument itself.
基金the research grant from Institute of Crustal Dynamics,CEA (No.ZDJ2013-07)Key Project of the National Twelfth-Five Year Research Program of China (No.2012BAK19B)
文摘Borehole inclinometers are important observation instruments used to measure ground tilt movement and monitor crustal deformation of solid tides and geological landslide disasters.They are widely used in oil exploration,mineral resource drilling,well logging,exploration and other fields.There is potential for development of rock stress strain monitoring tools.Many types of tiltmeters have been installed,such as SQ-7,FSQ,VS and JB.However,these tiltmeters are generally installed in a deep cave to avoid the interference of temperature,humidity,and human activities.With the urbanization of human society,suitable installation locations are difficult to find.To solve the problem,a two-component borehole tiltmeter,named the CBT-type tiltmeter,is proposed in this paper.It can be installed in a borehole less than500 m deep to eliminate environmental influences.The tiltmeter is composed of two sophisticated gravitational swing and two capacitive transducers.From preliminary theory and experiment analysis,its linear correlation coefficient is higher than 0.99,its co-seismic response is rapid and its noise level is up to 10 4arc seconds in practice.
