检索结果-南通市图书馆

Science China(Technological Sciences) 2021年第11期64卷 2551-2559页

作者： ZHAO ShuFan SHEN XuHui LIAO Li zeren zhima National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Institute of Geophysics China Earthquake AdministrationBeijing 100081China

Over the last century, abnormal electromagnetic(EM) emissions associated with earthquake(EQ) activities have been widely reported and recorded by ground-based and satellite observations. The mechanism of extremely low-frequency(ELF) EM waves radiated from earthquakes has been gradually established. However, whether EM waves radiated from earthquakes can be detected by low Earth orbit(LEO) satellites remains controversial. In this paper, to address these concerns, a lithosphereatmosphere-ionosphere model of ELF wave propagation is constructed. The features of the simulated EM field at LEO satellite altitudes radiated from earthquakes have been studied. The simulated EM field at the altitude of the China Seismo-Electromagnetic Satellite(CSES) is compared with the sensitivity of electromagnetic(EM) sensors onboard the CSES. The results illustrate that an earthquake with a magnitude over 6.0 can be detected by the EM sensors of the CSES. However, this depends on the focal depth, seismogenic environment and ionospheric parameters.

关键词： earthquakes CSES satellite sensitivity trans-lithosphere-atmosphere-ionosphere ELF wave propagation model

Joint observations of the large-scale ULF wave activity from space to ground associated with the solar wind dynamic pressure enhancement

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第7期67卷 2215-2229页

作者： SUN XiaoYing HU YunPeng zhima zeren DUAN SuPing LV FangXian SHEN XuHui National Institute of Natural Hazards Ministry of Emergency ManagementBeijing 100085China School of Space and Environment Beihang UniversityBeijing 102206China State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China

This study reports the rare ultralow-frequency(ULF) wave activity associated with the solar wind dynamic pressure enhancement that was successively observed by the GOES-17(Geostationary Operational Environmental Satellite) in the magnetosphere, the CSES(China Seismo-Electromagnetic Satellite) in the ionosphere, and the THEMIS ground-based observatories(GBO) GAKO and EAGL in the Earth's polar region during the main phase of an intense storm on 4 November 2021. Along with the enhanced-pressure solar wind moving tailward, the geomagnetic field structure experienced a large-scale change. From dawn/dusk sides to midnight, the GAKO, EAGL, and GOES-17 sequentially observed the ULF waves in a frequency range of0.04–0.36 Hz at L shells of ~5.07, 6.29, and 5.67, respectively. CSES also observed the ULF wave event with the same frequency ranges at wide L-shells of 2.52–6.22 in the nightside ionosphere. The analysis results show that the ULF waves at ionospheric altitude were mixed toroidal-poloidal mode waves. Comparing the ULF waves observed in different regions, we infer that the nightside ULF waves were directly or indirectly excited by the solar wind dynamic pressure increase: in the area of L-shells~2.52–6.29, the magnetic field line resonances(FLRs) driven by the solar wind dynamic pressure increase is an essential excitation source;on the other hand, around L~3.29, the ULF waves can also be excited by the outward expansion of the plasmapause owing to the decrease of the magnetospheric convection, and in the region of L-shells ~5.19–6.29, the ULF waves are also likely excited by the ion cyclotron instabilities driven by the solar wind dynamic pressure increase.

关键词： ultralow-frequency(ULF)wave solar wind dynamic pressure(P_(sw)) magnetic field line resonance(FLR) ion cyclotron instability

Detecting seismic electromagnetic ELF anomalies associated with the 2010 Yushu earthquake in China by DEMETER observations and ELF Lithosphere-Atmosphere-Ionosphere coupling propagating model

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第4期66卷 1192-1202页

作者： LIAO Li ZHAO ShuFan SHEN XuHui zeren zhima PENG HuaiYun LU HengXin Institute of Geophysics China Earthquake AdministrationBeijing 100081China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China China Research Institute of Radiowave Propagation Qingdao 266107China

Over the last century,abnormal electromagnetic(EM)emissions associated with earthquake(EQ)activities have been widely reported and recorded by ground-based and satellite ***,the frequency at which abnormal EM emissions have been detected *** addition,whether low Earth orbit(LEO)satellites can detect EM anomalies from EQs remains *** this paper,we take the Yushu earthquake as an example to address these concerns by DEMETER satellite observations and a newly constructed lithosphere-atmosphere-ionosphere model of extremely low frequency(ELF)wave *** results illustrate that the frequency of ELF EM anomalies of the Yushu earthquake is mainly at 200–400 *** observations and simulations illustrate that the power-frequency curve of the ELF EM wave from an underground source has a peak power frequency at 200–400 Hz,which is significantly different from the ELF EM wave radiated from the ground source.

关键词： seismic electromagnetic anomalies extremely low frequency(ELF)wave low Earth orbit(LEO)satellites lithosphereatmosphere-ionospheremodel

Preliminary geological interpretation of long-wavelength magnetic anomalies over China and surrounding regions

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第3期8卷 445-458页

作者： Jie Wang YanYan Yang zhima zeren Jian Wang Xin Wang YuXin Luo XuHui Shen National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Key Laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing 100085China School of Emergency Management Science and Engineering University of Chinese Academy of SciencesBeijing 100049China National Space Science Center Chinese Academy of SciencesBeijing 100190China

Long-wavelength(>500 km)magnetic anomalies originating in the lithosphere were first found in satellite magnetic *** to the striking magnetic anomalies around the world,the long-wavelength magnetic anomalies in China and surrounding regions are relatively *** research on each of these anomalies has been quite inadequate;their geological origins remain unclear,in particular their connection to tectonic activity in the Chinese and surrounding *** focus on six magnetic high anomalies over the(1)Tarim Basin,(2)Sichuan Basin(3)Great Xing’an Range,(4)Barmer Basin,(5)Central Myanmar Basin,and(6)Sunda and Banda Arcs,and a striking magnetic low anomaly along the southern part of the Himalayan-Tibetan *** have analyzed their geological origins by reviewing related research and by detailed comparison with geological *** tectonic backgrounds for these anomalies belong to two cases:either ancient basin basement,or subduction-collision ***,the geological origins of large-scale regional magnetic anomalies are always subject to dispute,mainly because of limited surface exposure of sources,later tectonic destruction,and superposition of multi-phase events.

关键词： long-wavelength magnetic anomaly lithospheric magnetic anomaly lithospheric magnetic field model satellite magnetic survey CSES

Ionospheric TEC and plasma anomalies possibly associated with the 14 July 2019 M_(w) 7.2 Indonesia Laiwui earthquake,from analysis of GPS and CSES data

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2022年第4期6卷 313-328页

作者： YuanZheng Wen Dan Tao GuangXue Wang JiaYi Zong JinBin Cao Roberto Battiston zhima zeren XuHui Shen Key Laboratory of Earth Exploration and Information Techniques of Ministry of Education Chengdu University of TechnologyChengdu 610059China School of Geophysics Chengdu University of TechnologyChengdu 610059China School of Space and Environment Beihang UniversityBeijing 100191China Dipartimento di Fisica Universitàdi TrentoTrento 38123Italy Trento Institute for Fundamental Physics and Applications(TIFPA) National Institute for Nuclear Physics(INFN)Trento 34136Italy National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China

This study presents signatures of seismo-ionospheric perturbations possibly related to the 14 July 2019 M_(w)7.2 Laiwui earthquake,detected by a cross-validation analysis of total electron content(TEC)data of the global ionospheric map(GIM)from GPS and plasma parameter data recorded by the China Seismo-Electromagnetic Satellite(CSES).After separating pre-seismic ionospheric phenomena from the ionospheric disturbances due to the magnetospheric and solar activities,we have identified three positive temporal anomalies,around the epicenter,at 1 day,3 days and 8 days before the earthquake(14 July 2019),along with a negative anomaly 6 days after the *** results agree well with the TEC spatial variations in latitude-longitude-time(LLT)*** confirm these anomalies further,we employed the moving mean method(MMM)to analyze ionospheric plasma parameters(electron,O^(+) and He^(+) densities)recorded by the Langmuir probe(LAP)and Plasma Analyzer Package(PAP)onboard the *** analysis detected on,on Day Two,Day Four,and Day Seven before the earthquake,remarkable enhancements along the orbits around when in proximity to the *** make the investigations still more convincing,we compared the orbits on which anomalous readings were recorded to their corresponding four nearest revisiting orbits;the comparison did indeed indicate the existence of plasma parameter anomalies that appear to be associated with the Laiwui *** these results ilustrate that the unusual ionospheric perturbations detected through GPS and CSES data are possibly associated with the M_(w)7.2 Laiwui earthquake,which suggests that at least some earthquakes may be predicted by alertness to pre-seismic ionospheric anomalies over regions known to be at seismic *** case study also contributes additional information of value to our understanding of lithosphere-atmosphere-ionosphere coupling.

关键词： seismo-ionospheric perturbations CSES sallite ionosphere earthquake

Disturbance identification of electric field data observed by the CSES-01 satellite before earthquakes

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2023年第8期66卷 1814-1824页

作者： Jianping HUANG Fuzhi ZHANG Zhong LI Xuhui SHEN Baiyi YANG Wenjing LI zhima zeren Hengxin LU Qiao TAN National Institute of Natural Hazards Ministry of Emergency ManagementBeijing 100085China Institute of Intelligent Emergency Information Processing Institute of Disaster PreventionLangfang 065201China

Numerous studies have confirmed that electromagnetic disturbances before earthquakes can be observed by *** this study,we use the C-value method that includes the acoustic whistle signature;pre-seismic ionospheric electromagnetic disturbance signals were acquired based on the CSES-01 satellite electric field data,and the maximum value of C in the earthquake preparation zones increased continuously from 2.0 three days before the earthquake and reached a maximum weight of 3.0 on the day of the earthquake,after the earthquake,it gradually decreased and recovered to about 2.0;its the C values fluctuated between-2 and 3,it is different from the C values range-2–12 of the previous seismic case study using the DEMETER satellite,which may be related to the orbital altitude and revisit period of the ***,the C values were normalized,and the time series analysis of the obtained θ values were done,and the results showed that:In the pregnant zone,the background variation of the disturbance amplitude θ is within 2σ,and the maximum disturbance amplitude of θ starts to increase gradually from the seventh period(one period of 5 days,i.e.,35–39 days before the earthquake),it reached 2σ by the fourth preseismic cycle(20–24 days before the earthquake),and then dropped sharply to about 1.5σ in the third pre-seismic cycle(15–19days before the earthquake),after two cycles of increase,the θ over the epicenter reached a maximum of 2.1σ at the time of the earthquake(combining the time of the earthquake and the satellite flight characteristics,the epicenter period is defined as January25-January 29,2020,and this defines the study time period line),and the θ decreases to within 2 times the standard range after the earthquake;The negative value of the disturbance amplitude θ in the central region of the pregnant seismic zone during the earthquake shows the transient energy release *** comparison,the θ values obtained by normalization based on the C-value method

关键词： The CSES-01 satellite Whistle Electric field C-value method Normalization

Stability validation on the VLF waveform data of the China-Seismo-Electromagnetic Satellite

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2022年第12期65卷 3069-3078页

作者： YANG DeHe zhima zeren WANG Qiao HUANG JianPing WANG XiuYing ZHANG ZhenXia ZHAO ShuFan GUO Feng CHENG WanLi LU HengXin SHEN XuHui National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Henan Earthquake Agency Zhengzhou 450016China

The China-Seismo-Electromagnetic Satellite(CSES),which was launched in February 2018,carries the search coil magnetometer(SCM)and the electric field detector(EFD)to realize the high-resolution electromagnetic field and wave detection in the upper *** to the complexity and variability of the ionospheric environment,the stability of such a high sampling rate and high-precision electromagnetic field detection systems is always an essential link in data processing and the scientific application of *** work evaluates the stability of the very-low-frequency(VLF)band detection by validating the systemic sampling-time differences between SCM and EFD in the VLF burst-mode *** optimal waveform data preprocessing method is put forward according to the noise levels of the VLF burst-mode observation and the inherent design characteristics of *** VLF waveform data of EFD is rebuilt by filling the data gaps among the sampling sub-periods,making it with a similar sample length to *** by precisely intercepting the maximum and minimum values of the burst-mode waveforms,the variation of the sampling-time difference between EFD and SCM is statistically *** show that during the three years'operation,the sampling-time difference between EFD and SCM predominately keeps below 0.5 s,indicating good stability of EFD and SCM on *** we developed an automatic synchronization tool based on the similarity function and STA/LTA(short time average over long time average)characteristic *** tool can effectively realize the precise synchronization between SCM and EFD in the VLF burst-mode *** work is helpful to upgrade the data quality of CSES and provides technical support for electromagnetic wave propagation studies.

关键词： stability CSES EFD SCM sampling-time difference quasiperiodic waves

Initial scalar lithospheric magnetic anomaly map of China and surrounding regions derived from CSES satellite data

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2021年第5期64卷 1118-1126页

作者： WANG Jie SHEN XuHui YANG YanYan zeren zhima HULOT Gauthier OLSEN Nils ZHOU Bin MAGNES Werner DE SANTIS Angelo HUANG JianPing GUO Feng LIU WenLong YU JingBo National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China School of Space and Environment Beihang UniversityBeijing 100191China Universitéde Paris Institut de physique du globe de ParisCNRSParis F-75005France DTU Space National Space InstituteTechnical University of DenmarkKongens Lyngby 2800Denmark National Space Science Center Chinese Academy of SciencesBeijing 100190China Space Research Institute Austrian Academy of SciencesGraz 8042Austria Istituto Nazionale di Geofisica e Vulcanologia Via di Vigna MurataRome 605Italy School of Earth Sciences Hebei GEO UniversityShijiazhuang 050031China

The China Seismo-Electromagnetic Satellite(CSES),China’s first satellite to measure geophysical fields with scientific goals in both space and solid earth physics,was launched successfully in February *** carries high-precision magnetometers to measure the geomagnetic *** this study,the CSES magnetic data were used to extract the signal of the lithospheric magnetic field caused by magnetized rocks in the crust and uppermost ***,an along-track analysis of the CSES magnetic data was undertaken near the Bangui magnetic anomaly in central Africa and the Tarim magnetic anomaly in China,demonstrating that the CSES magnetic data are indeed sensitive to the lithospheric magnetic anomaly *** a lithospheric magnetic anomaly map over China and surrounding regions was *** map is consistent with the lithospheric part of the CHAOS-7 *** particular,it clearly reveals four major magnetic anomalies containing long-wavelength signals at the altitude of lowearth-orbiting *** magnetic highs are located over the Tarim,Sichuan and Songliao basin,the origins of which could be related to large-scale tectonic-magmatic activities during geological history.A prominent magnetic low is otherwise found in the southern Himalayan-Tibetan plateau,possibly caused by the shallow Curie depth in this *** further improve the precision of the lithospheric magnetic field model,more detailed data processing and multi-source data merging are needed.

关键词： anomaly lithospheric Himalayan

Consistent Distribution of Stress before Strong Earthquake from Focal Mechanisms

在线全文

学校读者我要写书评

暂无评论

Earthquake Research in China 2010年第4期24卷 415-422页

作者： zeren zhima Diao Guiling Li Zhixiong Institute of Earthquake Science China Earthquake Administration Beijing 100036 China Earthquake Administration of Hebei Province Shijiazhuang 050021 China

At some stage of a strong earthquake preparation, the focal mechanisms of small earthquakes have roughly the same direction with the tectonic stress field. According to this feature, we define the angle between P, B and T axis of focal mechanisms and the three stress axes of tectonic stress field as the consistency parameter a in studying the dynamic changes of stress fields in earthquake preparation areas. We mainly analyze the changes of the consistency parameter a of the Mw8. 3 Knril island arc earthquake and the Mw8. 4 Peru earthquake. Our study shows that before the strong earthquakes, the earthquake area saw a low consistency, and the focal mechanisms of a series of small earthquakes had small differences in the directions with the tectonic stress field, which means the foreshocks were under the control of the stress field. On the other hand, a higher consistency means the focal mechanisms of their aftershocks are scattered and have big differences in the directions with the tectonic field, which indicate that the control of background stress field starts weakening.

关键词： Focal mechanisms The consistency Kuril Island Peru Stress field

Cross-calibration on the electromagnetic field detection payloads of the China Seismo-Electromagnetic Satellite

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2022年第6期65卷 1415-1426页

作者： zhima zeren ZHOU Bin ZHAO ShuFan WANG Qiao HUANG JianPing ZENG Li LEI JunGang CHEN Yu LI Cheng YANG DeHe SUN XiaoYing MIAO YuanQing ZHU XingHong SHEN XuHui National Institute of Natural Hazards Ministry of Emergency ManagementBeijing 100081 China National Space Science Center Chinese Academy of SciencesBeijing 100190China School of Space and Environment Beihang UniversityBeijing 100191China Lanzhou Institute of Physics China Aerospace Science and TechnologyGansu 730000China Aerospace Dongfanghong Satellite Co. Ltd.Beijing 572699China

The China Seismo-Electromagnetic Satellite(CSES)deploys three payloads to detect the electromagnetic environment in the *** tri-axial fluxgate magnetometers(FGM),as part of the high precision magnetometer(HPM),measures the Earth magnetic vector field in a frequency range from direct current(DC)to 15 *** tri-axial search coil magnetometer(SCM)detects the alternating current(AC)related magnetic field in a frequency range from several Hz to 20 k Hz,and the electric field detector(EFD)measures the spatial electric field in a broad frequency band from DC to 3.5 *** work mainly crosscalibrates the consistency of these three payloads in their overlapped detection frequency range and firstly evaluates CSES’s timing system and the sampling time differences between EFD and SCM.A sampling time synchronization method for EFD and SCM waveform data is put *** consistency between FGM and SCM in the ultra-low-frequency(ULF)range is validated by using the magnetic torque(MT)signal as a reference.A natural quasiperiodic electromagnetic wave event verifies SCM and EFD’s consistency in extremely low-frequency and very low-frequency(ELF/VLF)*** cross-calibration work is helpful to upgrade the data quality of CSES and brings valuable insights to similar electromagnetic detection solutions by low earth orbit satellites.

关键词： CSES cross-calibration HPM EFD SCM sampling time synchronization detection consistency ULF/ELF/VLF