中国地震速报台网走时残差分析与走时修正   总被引：4，自引：0，他引：4  

薛峰  赵永 《地震地磁观测与研究》1998,19(4):48-54

使用了３０个速报台站的观测数据,计算了１００多个中国境内外的地震事件初至波走时残差。在此基础上分析各台所记录的所有地震事件的残差随方位角和震中距的分布,及产生这些残差的地球深部非流体静力平衡状态和地球表面构造等方面的原因,并给出了不同区域地震走时的平均校正值,从而提高了地震定位精度。  相似文献   

Depth Distribution of Moho Discontinuity Beneath Beijing and Its Adjacent Area     

Ma Lin  Zheng Sihua  and Xue FengCenter for Analysis  Prediction  CSB  Beijing  China 《中国地震研究》1998,(3)

Based on the method of "two-dimensional depth structure of the crust" proposed by Horiuchi et al., about 5000 arrival times of 303 local shallow earthquakes recorded by the Beijing Seismographic Network from 1990 ~ 1993 are used to investigate the depth distribution of Moho discontinuity beneath Beijing and its adjacent area. We simultaneously determined the hypocenter parameters and P- and S-wave station corrections. The data of the North China Network were also investigated. The results are as follows: (1) The depth distribution of Moho discontinuity becomes shallower from the northwest to the southeast, i.e., in Zhangjiakou area, the Moho discontinuity is located at a depth range from 40~42 km. In the Beijing area, it is 36~39 km. However, at the eastern and southeastern part of this area, it is only 28-30 km and 30~32 km, respectively. (2) Beneath the Tangshan area, there is another elliptic interface shallower than the Moho discontinuity. Separately, its major and minor axis is approximately along  相似文献   

The Influence of Chlorine on the Determination of Combined Water: An Investigation of a Correction Procedure   总被引：2，自引：0，他引：2  

Jile Li  Wenzhang Liu 《Geostandards and Geoanalytical Research》1998,22(2):203-208

Differential thermal analysis, pH determination and ion chromatography were used to investigate the interference of chlorine in the determination of combined water (H₂O⁺) by the Penfield tube gravimetric method. The magnitude of the chlorine interference was quantified and a correction method was proposed to obtain accurate results for H₂O⁺. The method was applied to the determination of H₂O⁺ in deep sea sediments containing chlorine and certified reference materials of oceanic polymetallic nodules.  相似文献   

NEAR-FAULT DISPLACEMENT AND DEFORMATION OBTAINED FROM ONE-KILOMETER-LONG FAULT-CROSSING BASELINE MEASUREMENTS-A PRELIMINARY EXPERIMENT AT 2 SITES ON THE EASTERN BOUNDARY OF THE SICHUAN-YUNNAN BLOCK          下载免费PDF全文

CAO Jian-ling  ZHANG Jing  WEN Xue-ze  FENG Wei  SHI Yao-lin 《地震地质》1979,42(3):612-627

The current and conventional fault-crossing short baseline measurement has a relatively high precision, but its measurement arrays usually fail to or cannot completely span major active fault zones due to the short length of the baselines, which are only tens to 100 meters. GNSS measurement has relatively low resolution on near-fault deformation and hence is not suitable for monitoring those faults with low motion and deformation rates, due to sparse stations and relatively low accuracy of the GNSS observation. We recently built up two experimental sites on the eastern boundary of the active Sichuan-Yunnan block, one crossing the Daqing section of the Zemuhe Fault and the other crossing the Longshu section of the Zhaotong Fault, aiming to test the measurement of near-fault motion and deformation by using fault-crossing arrays of one-kilometer-long baselines. In this paper, from a three-year-long data set we firstly introduce the selection of the sites and the methods of the measurement. We then calculate and analyze the near-field displacement and strain of the two sites by using three hypothetical models, the rigid body, elastic and composed models, proposed by previous researchers. In the rigid body model, we assume that an observed fault is located between two rigid blocks and the observed variances in baseline lengths result from the relative motion of the blocks. In the elastic model, we assume that a fault deforms uniformly within the fault zone over which a baseline array spans, and in the array baselines in different directions may play roles as strainmeters whose observations allow us to calculate three components of near-fault horizontal strain. In the composed model, we assume that both displacement and strain are accumulated within the fault zone that a baseline array spans, and both contribute to the observed variances in baseline lengths. Our results show that, from the rigid body model, variations in horizontal fault-parallel displacement component of the Zemuhe Fault at the Daqing site fluctuate within 3mm without obvious tendencies. The displacement variation in the fault-normal component keeps dropping in 2015 and 2016 with a cumulative decrease of 6mm, reflecting transverse horizontal compression, and it turns to rise slightly(suggesting extension)in 2017. From the elastic model, the variation in horizontal fault-normal strain component of the fault at Daqing shows mainly compression, with an annual variation close to 10^-5, and variations in the other two strain components are at the order of 10^-6. For the Longshu Fault, the rigid-body displacement of the fault varies totally within a few millimeters, but shows a dextral strike-slip tendency that is consistent with the fault motion known from geological investigation, and the observed dextral-slip rate is about 0.7mm/a on average. The fault-parallel strain component of the Longshu Fault is compressional within 2×10^-6, and the fault-normal strain component is mainly extensional. Restricted by the assumption of rigid-body model, we have to ignore homolateral deformation on either side of an observed fault and attribute such deformation to the fault displacement, resulting in an upper limit estimate of the fault displacement. The elastic model emphasizes more the deformation on an observed fault zone and may give us information about localizations of near-fault strain. The results of the two sites from the composed model suggest that it needs caution when using this model due to that big uncertainty would be introduced in solving relevant equations. Level surveying has also been carried out at the meantime at the two sites. The leveling series of the Daqing site fluctuates within 4mm and shows no tendency, meaning little vertical component of fault motion has been observed at this site; while, from the rigid-body model, the fault-normal motion shows transverse-horizontal compression of up to 6mm, indicating that the motion of the Zemuhe Fault at Daqing is dominantly horizontal. The leveling series of the Longshu site shows a variation with amplitude comparable with that observed from the baseline series here, suggesting a minor component of thrust faulting; while the baseline series of the same site do not present tendencies of fault-normal displacement. Since the steep-dip faults at the two sites are dominantly strike-slip in geological time scale, we ignore probable vertical movement temporarily. In addition, lengths of homolateral baselines on either side of the faults change somewhat over time, and this makes us consider the existence of minor faults on either side of the main faults. These probable minor faults may not reach to the surface and have not been identified through geological mapping; they might result in the observed variances in lengths of homolateral baselines, fortunately such variations are small relative to those in fault-crossing baselines. In summary, the fault-crossing measurement using arrays with one-kilometer-long baselines provides us information about near-fault movement and strain, and has a slightly higher resolution relative to current GNSS observation at similar time and space scales, and therefore this geodetic technology will be used until GNSS networks with dense near-fault stations are available in the future.  相似文献   

TOVS资料真实性检验和偏差订正方案的设计   总被引：2，自引：1，他引：1  

韩桂荣  张菊芳  陈必云  冯民学  周曾奎 《气象》1998,24(7):40-44

具有空间高分辨率的卫星垂直探测（ＴＯＶＳ）资料应用于业务时,应对反演资料的偏差分布进行检验、统计、分析,以利于选取误差稳定且较小的区域（或指标点）作为寻求和归纳预报条件时可应用于业务的反演资料;同时,进一步研究和设计了误差订正方案,经比较分析,单点指标站经回归订正后误差能得到满意的改善,而经采用变分分析后的格点场质量能得到显著提高  相似文献   

MPI环境下基于边界校正方法的海洋模型的并行化     

符晓单  李洪平 《海洋科学》2015,39(5):62-67

基于区域分解技术,设计了一种针对海洋模型的边界校正方法,该方法不需要对原有海洋模型进行较大改动,只需要利用消息传递接口(message passing interface,MPI)编写子区域间的数据传输模块,即可实现原有海洋模型的并行化。相对于重新开发并行系统,该方法能够较快把原有模型的串行解决方案转化为并行解决方案,并且并行化后的海洋模型能够获得较高的加速比。  相似文献   

沿海GNSS观测网中BERNESE软件处理方案比较     

王朝阳  周兴华  张化疑  周东旭  侯雪 《海洋测绘》2015,35(1):52-55

采用BERNESE软件"OBS-MAX"和"SHORTEST"两种独立基线生成方式和三种网平差基准定义方法制定出6种GNSS数据后处理方案,分别对中国沿海GNSS业务化观测网2009年与2011年的两批数据处理,并从外符合和内符合精度两个方面进行分析比较。结果表明:采用"OBS-MAX"独立基线生成方式得出的坐标精度更优,尤其是在原始观测数据质量不高的情况下;在网平差基准定义上,采用固定解得出的坐标内符合精度优于最小约束解,但其外符合精度较差。  相似文献   

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朱春春  李征航  屈小川  申小平 《大地测量与地球动力学》2015,35(1):81-86

??RINEX HO???????GPS?????λ?????е???(?????????)????????????????????GPS???????е??????????(ΔI_H)^p,q_i,g??????????(ΔI_H)^p,q_i,g????γ?????????????????????????????????????????????????????￡???Bernese 5.0???????????????????????????????δ???и????????????????????л????????????????????????????????Δb_H???????????Δb_H???????С????????????????????Δ??b??H??????????????????????????????????????????ε??С??Δb_H?????????  相似文献   

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张品  申重阳  杨光亮  张晓彤  陈钊 《大地测量与地球动力学》2015,35(2):318-321

?????????????GPS?????ASTER GDEM?????д???????????????????????????θ????е????????????????????????ASTER GDEM????????-??????-????????????????У??????GPS?????????????14.93 m??18.02 m???????????????????н???????????С???????С???????????????????????θ????У?ASTER GDEM???????????????á?  相似文献   

雷达技术支持下的福州市地铁沿线形变监测     

陈安平  谭远模  阳成  覃永基 《测绘通报》2021,(7):86-91,97

近年来,由于地铁等地下工程大规模的建设产生了严重的地表沉降,从而诱发许多地质灾害,严重阻碍了中国城市化进程。因此,采用高精度雷达监测技术,对城市地质灾害监测及风险评估具有重要意义。本文利用SBAS-InSAR技术,基于24景X波段TerraSAR数据和32景C波段Sentinel-1数据,时间跨度分别为2013年7月至2015年8月、2015年7月至2018年2月,对地铁建设完成后的福州市区地表沉降进行长时间系列形变监测。监测结果表明,研究区域内的最大沉降速率为-12 mm/a,在整个观测周期内发现了8个沉降漏斗。并对这些区域进行进一步的时间序列分析,其中有3个区域呈现出地质灾害初期的特征,并且地表沉降存在进一步加剧的可能。  相似文献