共查询到18条相似文献，搜索用时 459 毫秒
1.
识别前震余震的单键群方法 总被引：3，自引：0，他引：3
本文提出一种从地震目录中识别强震的前震和余震并形成序列目标的新方法,即：以单键群（ＳＬＣ）分析方法为基础,定义在ＳＬＣ构架中,由于小于或等于特征键长的键所形成的许多链中,那些处在某个强震联通的链上的地震就与该强震构成一个地震序列;在此序列中,该强震为主震,之后的为余震,用此方法,可以按强震逐个识别其前震余震,并形成其序列目录。我们用它识别处理了海城７．４级和昆仑山－阿尔金山弧型顶部地区６．０级以上 相似文献
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为研究中国地震分布的时空特征,采用时空联合的单键群（ＳＬＣ）方法,计算了１９７０－１９９８年３月间该区域发生的４级和４级以上地震的时空ＳＬＣ构架．对时空ＳＬＣ构架所做的统计分析表明：①截止键长Ｄ在 ５０－８０ｋｍ范围内时,地震集团的个数 Ｔ（ｎ）与集团的大小 ｎ（所含地震个数）之间是自相似分布．在６５ ｋｍ附近,ｌｇＴ（ｎ）与 ｌｇｎ之间的线性相关性最好;②构架的累计键长符合Ｗｅｉｂｕｌｌ分布;③在删除前震和余震之后,构架的累计键数也服从Ｗｅｉｂｕｌｌ分布． 相似文献
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LOCT近震综合处理程序的原理与应用 总被引：1，自引：0，他引：1
ＬＯＣＴ是针对遥测地震台网对近震（△≤１０００ｋｍ）进行综合性处理工作而编写的ＢＡＳＩＣ优化程序．主体程序由数字化仪输入（含人工输入和文件输入）地震波数据．用交切法、偶台中线与Ｓ－Ｐ联合测定法、虚波走时迭代法测定地震参数，震级ＭＬ的计算，地震目录和报告数据的文件输出等部分组成．具有使用方便，灵活可靠，程序自身保护性好，地震参数的测定速度快、精度高，各种功能既相互独立，又统一于一体，互相补充，功能全面等特点．是进行近震速报和生成目录及报告的理想的实用程序． 相似文献
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中国地震历史资料的信息开发与利用 总被引：7，自引：1，他引：7
本文对全国历史地震资料的有用信息作了进一步的开发和利用，按统一方法处理了大量有感以上地震的文字记载，确字每个独立地震的时间与地点；分区求得地震的有感区长半径与震级的关系式；确定了历史有感地震的最低震级为４；取得了８０００余次有感地震垢基本参数；用等震线测定了巨大地震的参数；将有感强震目录统编成全国与几个大区Ｍ≥４．０地震目录，按《地震学地震预报实用程序系统》（ＥＰＳＥＩＳ）的格式要求建库；同时编制 相似文献
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用算法复杂性分析地震活动演化特征 总被引：5，自引：0，他引：5
以非线性动力学理论为依据，用非线性动力学中分析时间序列的算法复杂性研究地震活动规律和构成地震活动复杂现象的动力学特征。提出了按震级计算的地震算法复杂性ＡＣ值和按发震时间计算的地震算法复杂性ＴＡＣ值。选取１９７０年以来中国东部ＭＳ≥６．０地震，西部ＭＳ≥６．５的强震，对ＡＣ值和ＴＡＣ值进行回顾性分析；利用１９７０￣１９８０年大华北地区展望性空区识别结果，对ＡＣ值和ＴＡＣ值进行展望性检验分析，并进行了 相似文献
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采用统计检验方法,将天册地区ＭＬ≥３．６（Ｋ≥９．９）级地震目录与ＩＳＣ、ＮＥＩＣ、中国历史地震资料汇编、新疆地震目录进行对比检验,结果表明：天山地震目录与Ｉ、Ｎ、Ｚ、Ｘ地震目录的发震时刻及经纬度值无明显差异;天山地震目录给出的发震时刻、震源位置精度比其它任何一个地震目录者高;参检的各地震目录给出的震源深度离散度大,稳定性差;天山地震目录具有较高的可信度和可靠性。 相似文献
7.
应用Ｓｏｍｐｉ谱分析方法，对１９８９年１月至１９９０年７月发生在唐山地区的２０个地震和１９８８年７月至１９８９年１０月发生在大同周围地区１０个地震波（体波和面波）资料，及华北地区和西南地区自１９５９年以来ＭＬ≥２．０地震目录资料的频谱进行了分析，从而对几次大地震前地震波和地震活动性波频谱异常变化特征进行了研究。所得结果表明：较大地震前，地震波（体波和面波）及地震活动性的ｆｄ，均可能呈现出较明显的下降异常变化；地震波及地震活动性的ｆｄ变化可能成为地震预报的有用指标；Ｓｏｍｐｉ谱方法在处理地震波及地震活动性资料的应用是可行的 相似文献
8.
通过对运行地震目录管理软件ＣＡＴＭＡＮＡ．ＥＳＥ，挑出一守时空范围的地震时出现的错误结果进行分析，得出了正确使用ＣＡＴＭＡＮＡ．ＥＸＥ程序的前提条件以及实现这一条件的方法和计算程序。 相似文献
9.
介绍了Ω概率统计法的原理和计算公式，使用１９７０～１９９３年陕西省ＭＬ≥２．３级地震目录，用Ω概率统计法分析了陕西地震震级的分布特征，得到陕西省ＭＬ４．０和ＭＬ５．０级地震的复发周期。 相似文献
10.
CDSN台站典型震例数字地震图库的建立 总被引：2，自引：2，他引：0
主要描述利用ＵＮＩＸ的ＳＨＥＬＬ组合命令实现数字地震图库的建立。图库按时间顺序排列,地震波形文件与数据库中相关的表（ＴＡＢＬＥ）分开存放,波形文件是以ＣＳＳ３．０格式存储的,符合ＡＲＳ的使用习惯。使用时用户只需更改数据库的名字,即可使用功能很强的ＡＲＳ分析软件,对数字地震图进行回放处理等操作 相似文献
11.
Zhou Huilan Liu Zhen and Gao YuanGraduate School University of Sciences Technology of China Beijing China 《中国地震研究》1998,(1)
By using the SLC(Single-Link Cluster)method,this study worked in three respects:(a)set up three-dimensional(3-D)SLC software that can deal with a large catalogue of earthquakes and analyze the characteristics of earthquakes' clustering and scattering in time-space:(b)defined several parameters to describe the distinguishing feature for the SLC frame and developed a technique to calculate the 3-D SLC frames and these parameters with gradual time-sliding,and inspected their variations with time,especially before large events; and(c)by using these means,treated the earthquake catalogue in the top area of the Kunlun-Altun-Arc as well as some valuable results that had been obtained. 相似文献
12.
Using the method of Single-link Cluster(SLC),analyzing the pattern of time sliding of SLCparameters,the earthquake activity in the western Sichuan-Yunnan of China is studiedcombining with the regional earthquake catalogue since 1970 and the tectonic background.Comparing with the high level of earthquake activity in 1970’s and the low in 1980’s,theearthquake activity is in general at the middle level in 1990’s.This paper suggests that SLCmethod,which considers the temporal and spatial relationship among earthquake events,could be adopted to analyze the trend of regional earthquake activity,it is very useful forstudying seismic activity. 相似文献
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最新1/400万中国活动构造空间数据库的建立 总被引：2，自引：0，他引：2
以ArcGIS和MapInfo为软件平台,对邓起东院士多年来潜心研究和汇总的中国活动构造数据进行了数字化处理,采用统一的坐标系统、一致的投影方式和合理的数据库逻辑结构建立了中国活动构造空间数据库,实现了活动断裂、活动盆地、活动褶皱等活动构造及其各类相关参数的有效管理和系统集成,实现了图形数据和属性数据的相互查询,为各地震相关研究部门和工程建设部门利用这些数据提供了极大的方便 相似文献
17.
Uncertainty in recurrence rates of large magnitude events due to short historic catalogs 总被引：2，自引：0，他引：2
Seismic hazard analysis requires knowledge of the recurrence rates of large magnitude earthquakes that drive the hazard at low probabilities of interest for seismic design. Earthquake recurrence is usually determined through studies of the historic earthquake catalogue for a given region. Reliable historic catalogues generally span time periods of 100–200 years in North America, while large magnitude events (M?≥?7) have recurrence rates on the order of hundreds or thousands of years in many areas, resulting in large uncertainty in recurrence rates for large events. Using Monte Carlo techniques and assuming typical recurrence parameters, we simulate earthquake catalogues that span long periods of time. We then split these catalogues into smaller catalogues spanning 100–200 years that mimic the length of historic catalogues. For each of these simulated “historic” catalogues, a recurrence rate for large magnitude events is determined. By comparing recurrence rates from one historic-length catalogue to another, we quantify the uncertainty associated with determining recurrence rates from short historic catalogues. The use of simulations to explore the uncertainty (rather than analytical solutions) allows us flexibility to consider issues such as the relative contributions of aleatory versus epistemic uncertainty, and the influence of fitting method, as well as lending insight into extreme-event statistics. The uncertainty in recurrence rates of large (M?>?7) events is about a factor of two in regions of high seismicity, due to the shortness of historic catalogues. This uncertainty increases greatly with decreasing seismic activity. Uncertainty is dependent on the length of the catalogue as well as the fitting method used (least squares vs. maximum likelihood). Examination of 90th percentile recurrence rates reveals that epistemic uncertainty in the true parameters may cause recurrence rates determined from historic catalogues to be uncertain by a factor greater than 50. 相似文献
18.
For the Fiji-Tonga-Kermadec area and for the period from January 1977 to July 2003, the Harvard CMT catalogue lists 1022 shallow,
410 intermediate and 633 deep earthquakes of moment magnitude from 4.9 to 8.0. The magnitude threshold, above which the catalogue
is complete, is 5.3–5.4, and the number of earthquakes of magnitude above this value is 691 for shallow, 329 for intermediate
and 476 for deep events, respectively. The proportion of earthquakes associated with doublets and multiplets against the total
number of earthquakes is approximately the same in both data sets and therefore all earthquake pairs were considered regardless
of their magnitude. We investigated all the pairs of earthquakes that occurred at a centroid distance of less than 40, 60
or 90 km from each other and within a time interval of 200, 300 or 450 days, depending on their magnitude. We found 208 pairs
of shallow, 31 of intermediate and 92 of deep events. To ascertain whether these earthquakes in pairs are not connected by
chance, the possibility of their occurrence in an uncorrelated Poissonian catalogue was considered. It was assumed that in
such a catalogue the inter-event time is exponentially distributed, the earthquake magnitude follows the Gutenberg-Richter
relation, and the distribution of centroid distances between the events in pairs is controlled by its non-parametric kernel
estimate. The probability of the appearance of the observed proportion of doublets of shallow earthquakes in the Poissonian
catalogue was found to be very low. The low probability of occurrence in a semi-random catalogue, created by randomising centroid
locations in the actual data set, also indicates major importance of the distance criterion used for a doublet specification.
In general, shallow earthquakes tend to form pairs at shorter distances and within shorter time intervals than deep earthquakes.
Both the distance and the time intervals do not depend on the magnitude of involved events. The largest number of pairs of
deep earthquakes is observed at a depth of about 600 km, and the proportion of deep events associated with doublets against
the number of all events increases with depth. From comparison of the focal mechanism of earthquakes in pairs, measured by
the 3-D rotation angle, it follows that deep earthquakes forming pairs have a more diverse focal mechanism than shallow events;
the rotation angle for three quarters of shallow pairs and only for about one third of deep pairs is reasonably small. The
azimuth between two events forming a doublet is in about 60–65% of cases close to the strike of one of nodal planes of the
first or the second event. 相似文献