2014年美国加州纳帕M_W6.1地震断层参数的Sentinel-1A InSAR反演

2014年8月24日,在美国加州旧金山海湾北部的纳帕地区发生了MW6.1地震.发震断层是西纳帕断裂系统中的一部分,但是该断层之前并未被足够重视.本文利用欧洲空间局最近发射成功并刚刚投入使用的Sentinel-1A卫星获取的第一对同震干涉像对(20140807-20140831),得到了该地震的地表同震形变场,结合震后24h内区域GPS同震形变资料作为约束条件,反演了纳帕地震的断层几何参数以及滑动分布.Sentinel-1A干涉结果表明,此次地震造成了明显的地面形变,视线向最大抬升和最大沉降量均达到了10cm.联合反演结果表明,该发震断层的走向为344°,倾角为80°.主要破裂以右旋走滑为主,平均倾滑角为-146.5°,最大倾滑量达到了1.1m,位于地表下约4km,存在明显的滑动亏损现象.此次地震,累计释放地震矩达1.5×1018 N·m,约合矩震级MW6.1.该结果略小于InSAR单独约束结果,可能与Sentinel-1A像对中包含的快速震后形变分量有关.

Resolving co- and early post-seismic slip variations of the 2021 MW 7.4 Madoi earthquake in east Bayan Har block with a block-wide distributed deformation mode from satellite synthetic aperture radar data

On 21 May 2021(UTC),an MW 7.4 earthquake jolted the east Bayan Har block in the Tibetan Plateau.The earthquake received widespread attention as it is the largest event in the Tibetan Plateau and its surroundings since the 2008 Wenchuan earthquake,and especially in proximity to the seismic gaps on the east Kunlun fault.Here we use satellite interferometric synthetic aperture radar data and subpixel offset observations along the range directions to characterize the coseismic deformation of the earthquake.Range offset displacements depict clear surface ruptures with a total length of~170 km involving two possible activated fault segments in the earthquake.Coseismic modeling results indicate that the earthquake was dominated by left-lateral strike-slip motions of up to 7 m within the top 12 km of the crust.The well-resolved slip variations are characterized by five major slip patches along strike and 64%of shallow slip deficit,suggesting a young seismogenic structure.Spatial-temporal changes of the postseismic deformation are mapped from early 6-day and 24-day InSAR observations,and are well explained by time-dependent afterslip models.Analysis of Global Navigation Satellite System(GNSS)velocity profiles and strain rates suggests that the eastward extrusion of plateau is diffusely distributed across the east Bayan Har block,but exhibits significant lateral heterogeneities,as evidenced by magnetotelluric observations.The block-wide distributed deformation of the east Bayan Har block along with the significant co-and post-seismic stress loadings from the Madoi earthquake imply high seismic risks along regional faults,especially the Tuosuo Lake and Maqên-Maqu segments of the Kunlun fault that are known as seismic gaps.

Locating the Small 1999 Frenchman Flat, Nevada Earthquake with InSAR Stacking

Due to high interferometric coherence in the Nevada region,Interferometric Synthetic Aperture Radar(InSAR)phase stacking is capable of mapping coseismic signals from the 27 January 1999,M w 4.8 Frenchman Flat earthquake.This is one of the smallest earthquakes yet studied using InSAR with line-of-sight displacements as small as~1.5 cm.Modelling the event as dislocation in an elastic half space suggests that the fault centroid was located at(115.96°W,36.81°N)with a precision of 0.2~0.3 km(1σ)at a depth of 3.4±0.2 km.Despite the dense local seismic network in southern Nevada,differences as large as 2~5 km were observed between our InSAR earthquake location and those estimated from seismic data.The InSAR-derived magnitude appeared to be greater than that from seismic data,which is consistent with other studies,and believed to be due to the relatively long time interval of InSAR data.

交易商在铁矿石和其他工业矿物销售中的作用和贡献

叙述随着商业的全球化和竞争压力的加剧,交易商的作用和他参与活动的收益完全没有过时或被取代,相反则要求不断地增加服务和拓展其业务范围。

Successful Applications of Generic Atmospheric Correction Online Service for InSAR (GACOS) to the Reduction of Atmospheric Effects on InSAR Observations

The tremendous development of Synthetic Aperture Radar(SAR)missions in recent years facilitates the study of smaller amplitude ground deformation over greater spatial scales using longer time series.However,this poses greater challenges for correcting atmospheric effects due to the wider coverage of SAR imagery than ever.Previous attempts have used observations from Global Positioning System(GPS)and Numerical Weather Models(NWMs)to separate atmospheric delays,but they are limited by(1)The availability(and distribution)of GPS stations;(2)The low spatial resolution of NWM;And(3)The difficulties in quantifying their performance.To overcome these limitations,we have developed the Generic Atmospheric Correction Online Service for InSAR(GACOS)which utilizes the high-resolution European Centre for Medium-Range Weather Forecasts(ECMWF)products using an Iterative Tropospheric Decomposition(ITD)model.This enables the reduction of the coupling effects of the troposphere turbulence and stratification and hence achieves equivalent performances over flat and mountainous terrains.GACOS comprises a range of notable features:(1)Global coverage;(2)All-weather,all-time usability;(3)Available with a maximum of two-day latency;And(4)Indicators available to assess the model’s performance and feasibility.In this paper,we demonstrate some successful applications of the GACOS online service to a variety of geophysical studies.

Acceleration of Glacier Mass Loss after 2013 at the Mt.Everest(Qomolangma)

Satellite geodesy is capable of observing glacier height changes and most recent studies focus on the decadal scale due to limitations of data acquisition and precision.Glaciers at the Mt.Everest(Qomolangma),locating at the central Himalaya,have been studied from the 1970s to 2015.Here we obtained TerraSAR-X/TanDEM-X images observed in two epochs,a group around 2013 and another in 2017.Together with SRTM observed in 2000,we derived geodetic glacier mass balance between 2000 and 2013 and 2013 and 2017.We proposed two InSAR procedures for deriving the second period,which yields with basically identical results of geodetic glacier mass balance.The differencing between DEMs derived by TerraSAR-X/TanDEM-X shows better precision than that between TerraSAR-X/TanDEM-X formed DEM and SRTM,and it can capable of providing geodetic glacier mass balance at a sub-decadal scale.Glaciers at the Mt.Everest(Qomolangma)and its surroundings present obvious speeding up in mass loss rates before and after 2013 for both the Chinese and the Nepalese sides.The previous obtained spatial heterogeneous pattern for glacier downwasting between 2000 and 2013 generally kept the same after 2013.Glaciers with lacustrine terminus present the most rapid lost rates.

A Neural Network Algorithm to Detect Sulphur Dioxide Using IASI Measurements

The remote sensing of volcanic sulphur dioxide (SO2) is important because it is used as a proxy for volcanic ash, which is dangerous to aviation and is generally more difficult to discriminate. This paper presents an Artificial Neural Network (ANN) algorithm that recognizes volcanic SO2 in the atmosphere using hyperspectral remotely sensed data from the IASI instrument aboard the Metop-A satellite. The importance of this approach lies in exploiting all thermal infrared spectral information of IASI and its application to near real-time volcanic monitoring in a fast manner. In this paper, the ANN algorithm is demonstrated on data of the Eyjafjallajokull volcanic eruption (Iceland) during the months of April and May 2010, and on the Grímsvotn eruption occurring during May 2011. The algorithm consists of a two output neural network classifier trained with a time series consisting of some hyperspectral eruption datasets collected during 14 April to 14 May 2010 and a few from 22 to 26 May 2011. The inputs were all channels (441) in the IASI v3 band and the target outputs (truth) were the corresponding retrievals of SO2 amount obtained with an optimal estimation method. The validation results for the Eyjafjallajokull independent data-sets had an overall accuracy of 100% and no commission errors, therefore demonstrating the feasibility of estimating the presence of SO2 using a neural network approach also a in cloudy sky conditions. Although the validation of the neural network classifier on datasets from the Grímsvotn eruption had no commission errors, the overall accuracies were lower due to the presence of omission errors. Statistical analysis revealed that those false negatives lie near the detection threshold for discriminating pixels affected by SO2. This demonstrated that the accuracy in classification is strictly related to the sensitivity of the model. The lower accuracy obtained in detecting SO2 for Grímsvotn validation dates might also be caused by less statistical knowledge of such an eruption during the training phase.

Effect and Influence of Aryl Mercaptanes with Various Chain Lengths on DNA/RNA and Cadmium Oxide (CdO) Nanoparticles Sandwiched Complex

CdO(cadmium oxide)nanoparticles show a strong peak of Plasmon absorption in ultraviolet-visible zone.A strong interaction exists between the surface of CdO nanoparticles and aryl mercaptan compounds.Aryl mercaptan compounds cause aggregation of CdO nanoparticles linked to DNA/RNA(eoxyribonucleic acid/ribonucleic acid)and hence,lead to widening of peak Plasmon of CdO nanoparticles surface at 550 nm and emerge a new peak at higher wavelength.In the current project,this optical characteristic of CdO nanoparticles is used to investigate interaction time between different aryl mercaptanes and CdO nanoparticles.The results showed that aryl mercaptan compounds with shorter chain length interact faster with CdO nanoparticles.Therefore,a simple and fast method for identification of aryl mercaptanes with various chain lengths using red shift in surficial Plasmon absorption is presented.

Infrastructure of Synchrotronic Biosensor Based on Semiconductor Device Fabrication for Tracking, Monitoring, Imaging, Measuring, Diagnosing and Detecting Cancer Cells

Copper Zinc Antimony Sulfide(CZAS)is derived from Copper Antimony Sulfide(CAS),a famatinite class of compound.In the current paper,the first step for using Copper,Zinc,Antimony and Sulfide as materials in manufacturing synchrotronic biosensor-namely increasing the sensitivity of biosensor through creating Copper Zinc Antimony Sulfide,CZAS(Cu1.18Zn0.40Sb1.90S7.2)semiconductor and using it instead of Copper Tin Sulfide,CTS(Cu2SnS3)for tracking,monitoring,imaging,measuring,diagnosing and detecting cancer cells,is evaluated.Further,optimization of tris(2,2'-bipyridyl)ruthenium(II)(Ru(bpy)32+)concentrations and Copper Zinc Antimony Sulfide,CZAS(Cu1.18Zn0.40Sb1.90S7.2)semiconductor as two main and effective materials in the intensity of synchrotron for tracking,monitoring,imaging,measuring,diagnosing and detecting cancer cells are considered so that the highest sensitivity obtains.In this regard,various concentrations of two materials were prepared and photon emission was investigated in the absence of cancer cells.On the other hand,ccancer diagnosis requires the analysis of images and attributes as well as collecting many clinical and mammography variables.In diagnosis of cancer,it is important to determine whether a tumor is benign or malignant.The information about cancer risk prediction along with the type of tumor are crucial for patients and effective medical decision making.An ideal diagnostic system could effectively distinguish between benign and malignant cells;however,such a system has not been created yet.In this study,a model is developed to improve the prediction probability of cancer.It is necessary to have such a prediction model as the survival probability of cancer is high when patients are diagnosed at early stages.

Cyclone Bomb Hits Southern Brazil in 2020

An“explosive extratropical cyclone”is an atmospheric phenomenon that occurs when there is a very rapid drop in central atmospheric pressure.This phenomenon,with its characteristic of rapidly lowering the pressure in its interior,generates very intense winds and for this reason it is called explosive cyclone,bomb cyclone.With gusts recorded of 116 km/h,atmospheric phenomenon-“cyclone bomb”(CB)hit southern Brazil on June 30,the beginning of winter 2020,causing destruction in its influence over.One of the cities most affected was Chapecó,west of the state of Santa Catarina.The satellite images show that the CB generated a low pressure(976 mbar)inside it,generating two atmospheric currents that moved at high speed.In a northwest-southeast direction,Bolivia and Paraguay,crossing the states of Parana and Santa Catarina,and this draft that hit the south of Brazil,which caused the destruction of the affected states.Another moving to Argentina,southwest-northeast direction,due to high area of high pressure(1022 mbar).Both enhanced the phenomenon.

Focal mechanism inversion of the 2018 M_(W)7.1 Anchorage earthquake based on high-rate GPS observation

The M_(W)7.1 Anchorage earthquake is the most destructive earthquake since the 1964 M_(W)9.2 great Alaska earthquake in the United States.In this study,high-rate GPS data and near-field broadband seismograms are used in separate and joint inversions by the generalized Cut-and-Paste(gCAP)method to estimate the focal mechanism.In order to investigate the influence of crustal velocity structure on the focal mechanism inversion results,two velocity models(Crustl.0 and Alaska Earthquake Center(AEC))are used for detailed comparison and analysis.The results show that:(1)The two nodal planes of the optimal double-couple solution are nearly north-south striking,with dip angles of about 30°and 60°respectively,and the centroid focal depth is 54-55 km,which is an intraplate normal fault event.(2)The inversion results for the two types of data and the two velocity models are consistent with some previous studies,which indicates that the results are stable and reliable.The more accurate velocity structure model is helpful for focal mechanism inversion of the complex earthquake.(3)The inclusion of high-rate GPS data in joint inversion provides a more effective constraint on centroid depth.

ebeam Technologies:以电子束固化改变数字印刷

2017年9月,在比利时布鲁塞尔举办的Labelexpo Europe 2017展会同期,隶属于瑞士上市公司COMET集团公司的ebeam Technologies事业部出品的紧凑型固化单元荣获了'2017标签工业全球大奖'4个重量级奖项之一的'可持续发展大奖',该奖项表彰了ebeam在研发适用于窄幅轮转印刷机的紧凑型电子束固化系统方面的努力。

Sleep and Subjective Recovery in Amateur Trail Runners After the Ultra-Trail du Mont Blanc^(®)(UTMB^(®))

Purpose The interaction between sleep and recovery is a fundamental issue for ultra-marathoners,especially after an ultra-trail,but literatures on this matter remains are scarce.The main objectives were(1)to describe sleep parameters during the nights following an ultra-endurance event in amateur trail runners,(2)to evaluate the recovery kinetics,and(3)to assess the relationship between sleep parameters and recovery.Methods Nineteen race finishers were tested daily,from 10 days before to 10 days after the Ultra-Trail du Mont-Blanc^(®)(UTMB^(®)).Hooper Index(HI)was used to assess recovery and sleep parameters(total sleep time,TST and wake after sleep onset,WASO)were monitored using a wrist-worn actigraph.Results HI was higher than baseline until day 5 after the race(P<0.05)and younger athletes had a lower HI than older ones during the recovery period(P<0.001).TST was not modified by the race,but there was a WASO peak on the second night after.Positive correlations were found between WASO and muscle soreness(P<0.001)and between TST and HI(P<0.05).Conclusions In conclusion,participants needed 6 days for recovery after UTMB^(®)and younger runners seemed to recover faster than older ones.Post-race sleep quantity did not increase,but the second night was more fragmented,most likely due to muscle soreness.Correlations between sleep and recovery parameters highlighted the key role of sleep for recovery.

宽幅InSAR监测地震与火山形变研究进展

宽幅InSAR技术在过去10多年已在全球数字高程模型生成与大尺度地壳变形监测等领域起到了重要作用.本文的主要内容包括:(1)概述了宽幅InSAR的基本流程与约束条件;(2)利用宽幅InSAR方法得到了巴姆地震、汶川地震、于田地震、改则地震以及位于板块边缘东非裂谷火山活动形变场;(3)定量分析了Envisat ASAR宽幅与条带模式数据的入射角与方位角变化对InSAR地表形变观测的影响;(4)讨论了该技术的研究热点与亟待解决的问题.近期发射的C波段Sentinel-1与L波段ALOS-2PALSAR传感器具有较短重访周期及优化的轨道控制,可以提高植被和季节性雪覆盖的火山与活动断裂带区域的相干性,将有助于利用宽幅InSAR资料开展上述地区的大尺度、快速地壳形变场监测.

TWO POSSIBLE ACCELERATION MECHANISMS IN COMET TAIL

The large accelerations of plasma were observed early in type-Ⅰ comet tail. The accelerations can reach 300 cm/S^2. Recently, the direct measurements for comet G-Z show that the energy of particles reaches 2×10~5 eV. It is much higher than the initial

A PRELIMINARY STUDY OF THE TAIL OF COMET HALLEY AND THE GEOMAGNETIC STORM

Ⅰ. INTRODUCTION The famous Comet Halley (whose period P=76.1 years, orbital eccentricity e=0.9673, inclination of orbit i=16202) threw men into a great panic and nervous state on May 18, 1910 before its flying past the earth. When the comet’s tail swept over

THE PLASMA CONDITION FOR THE KINEMATICAL FORCE-FREE MAGNETIC FIELD

The force-free field describes the configuration of magnetic field in the solar chromosphere and coronal active region, in the Earth’s magnetosphere, and even in the comet plasma. The force-free field has extensive applications in the solar physical or space physical environment. Generally, the theoretical models of the force-free fields are constructed first, and then, compared with the observations. In the 50’s,