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1.
态矢量--分析地震活动性的一种新方法   总被引:7,自引:0,他引:7  
态矢量来源于统计物理学,是一种对连续场进行粗粒化描述的方法。现移植到地震学中用以定量地刻画地震活动性的演化,取得较好的结果。作者分析研究了几个著名震例(海城地震、唐山地震、昆仑山口西地震),发现地震前其态矢量均有显著的变化,因此认为它可能是大地震的一种前兆,而用之于地震预报。  相似文献   

2.
陈绍绪 《内陆地震》1996,10(3):201-208
通过对华北地区强震前兆场时空特征的研究,发现在强震的孕育过程中,异常的累积频次总是呈指数型增长并有较明显的阶段性。长期异常一般都发生在震源区附近;中期异常的分布范围向外扩大,而且基本上都分布在震源区的外围;短临异常的分布范围进一步扩大,在震源及外围地区都有发生。也就是说,地表异常的空间分布范围是由小到大逐渐扩展的,并有一个从"震源→外围→震源+外围"的转移过程。异常在空间上的分布是不均匀的,可能主要受台站分布的不均匀及构造活动的差异性影响.  相似文献   

3.
根据《中国震例》所载1966年至1985年以来,全国Ms≥5.0的58次中强地震的《震例》研究成果,从应用的角度出发,探讨了动态跟踪预测未来中强地震活动“时”、“空”、“强”的活动规律,得出如下启示:1)利用地震的前兆总体演变过程的阶段性以探讨定量预测其“活动时段”;2)利用地震的前兆总体分布图象以探讨定量预测其“活动空间”;3)利用地震的前兆环的规模以粗略地预估其未来强震的“活动强度”。还初步探讨了利用它们的“场”、“源”演变的关联性,提出文中一些作法的物理意义之所在。  相似文献   

4.
甘东南及其邻区地震活动性短期预报方案探索   总被引:1,自引:0,他引:1  
杨国栋  代炜  严武建 《高原地震》2007,19(3):10-12,28
根据甘东南及其邻区的地质构造特征、历史中强地震活动特征,尤其是中强地震前前兆小震活动特点,提出了适合于甘东南及其邻区的地震短期预报方案。这对开展该地区的预报工作,特别是对开展该地区的短期震情跟踪工作有着特别重要的意义。  相似文献   

5.
The concept of state vector stems from statistical physics, where it is usually used to describe the evolution of a continuum field in its way of coarse-graining. In this paper, the state vector is employed to depict the evolution of seismicity quantitatively, and some interesting results are presented The authors investigated some famous earthquake cases (e.g., the Haicheng earthquake, the Tangshan earthquake, the west Kunlun Mountains earthquake, etc.) and found that the state vectors evidently change prior to the occurrence of large earthquakes. Thus it is believed that the state vector can be used as a kind of precursor to predict large earthquakes.  相似文献   

6.
许俊奇 《华南地震》1995,15(1):38-42
在应用最优分割法对地震活动性分类研究的基础上引进线性模型,扩大最优分割法在地震活动性分类中的应用范围,并将聚类问题与建模问题有机地结合起来,以揭示地震活动的某种内在规律,这对于探索地震预报和地震的发生规律有一定实际意义。  相似文献   

7.
We examined the hypothesis that minima in local recurrence time, TL, or equivalently maxima in local probability, PL, may map asperities in the Kanto and Tokai areas of Japan, where the earthquake catalog of the National Research Institute for Earth Science and Disaster Prevention (NIED) is complete at the M=1.5 (M1.5) level. We mapped TL (PL) based on the a- and b-values of the nearest earthquakes within 20 km of every node of a grid spaced 0.01° for M7 target events. Only earthquakes within the top 33 km were used. The b-values increase strongly with depth, in several areas. Therefore, some of the TL (PL) anomalies are not revealed if data from the entire crustal seismogenic zone are mixed. Thus, we mapped TL (PL) separately for the top 15 km and the rest of the depth range, as well as for the entire seismogenic crust. The resulting TL- and PL-maps show that approximately 12% of the total area shows anomalously short recurrence times. Out of six shallow target events with M≥6.5 and which occurred since 1890, five are located within the anomalous areas with TL <450 years. We interpret this to mean that areas with anomalously short TL map asperities, which are more likely than other areas to generate future target events. The probability that this result is due to chance is vanishingly small. The great Kanto rupture of 1923 appears to have initiated in the most significant asperity we mapped in the study area. One anomaly is located in the northeastern part of the area of the proposed future rupture of the Tokai earthquake, and another one at its southwestern corner. The absolute values of TL calculated are uncertain because they depend on the size of the volume used for the calculation.  相似文献   

8.
徐人平  傅惠民 《地震研究》1994,17(4):340-349
本文在对年最大地震震级分布讨论了基础上,研究其置信度问题,运用数理统计方法,确定对地震活动趋势分析的可信程度,为中长期地震预报提供了依据。  相似文献   

9.
本文系统地介绍了青海省防震减灾工作的情况,并重点叙述了青海东部几次中强地震的短临预报及动态跟踪过程。  相似文献   

10.
对1999年5月17日万宁近海Ms4.8级地震进行了总结。分析认为,这次地震属孤立型,发震断层为NE向的兴隆-龙滚断裂和琼东南海断裂之间的次一级断裂,具有走滑特征。地震前存在3个月无ML≥3.0级地震的异常平静、低b值、应变释放加速、缺震、地震频度地CL高值以及琼中地磁台Z分量“双低点”等前兆异常现象。地震前有不同程度的中期和短期预报。  相似文献   

11.
郭培兰 《高原地震》2006,18(1):28-35
通过对广西及邻区(以下简称研究区)地震活动的背景,包括研究区地震活动特征、断裂带的分布、主压应力轴方向与强震发生的主体地区、地震活动时空扫描异常特点、强震发生的时间特点进行了分析,说明该地区存在发生中强震的可能。并对2004年广东阳江4.9级2、005年云南文山5.3级、2005年广西平果4.4级地震前的异常进行了分析,说明研究区地震活动特征显著。同时获得了区域中强以上地震前的主要异常指标,对今后地震预测有一定指导意义。  相似文献   

12.
刘蒲雄  陈兆恩 《地震》1997,17(2):113-125
通过多震例分析,表明大震前地震活动图像具有类似的演变形式,即空段-背景空区-增强活动-条带-平静,地震平静可以看作是中期短期过渡的地震活动性标志,从图像演变角有助于识别异常平静,并有可能把震前平静的时间尺度缩短至几个月量级。  相似文献   

13.
应用灰色理论GM(1,1)预测模型估计我国未来的地震趋势。为提高预测精度和反映“最新信息”,在组成原始数列时,对于M≥7.5级地震,由平静幕、活跃幕采用不同震级阈值联合组成;对于其它级别地震则尽可能采用当前活动期以来的数据。计算结果表明,1997 ̄2000年期间我国大陆及邻区有发生M≥7.5级地震的可能,大陆西部可能发生7.0至7.5级以上地震;东部可能发生5.5至6.0级以上地震。同时,估计本活  相似文献   

14.
库玛断裂带强震活动与地震空区研究   总被引:12,自引:0,他引:12       下载免费PDF全文
陈玉华  马文静 《地震》2002,22(2):81-87
库玛断裂带作为青藏高原内部的一条强地震活动带, 1900年以来发生过3次7级地震,其中2次7级大震前均出现5级以上地震的背景空区,表明背景空区对该带大震具有中长期预报意义。最近一次背景空区业已形成,并出现与之配套的孕震空区,其演化图像符合强震孕育模式。研究发现,库玛断裂带中段ML 3以上地震空区,对共和7级强震及周边200 km的强震有前兆意义。  相似文献   

15.
陈虹 《地震》2000,20(1):45-52
提出了二个描述中强震发生前中短期阶段地震活动异常时空演经图像的参量σN、σE。分别将其用于华北地区、新疆地震区及南北地震带,并对其预报效能进行检验,对其异常的空间分布图像与强震发生地震进行了分析,结果表明,该二参量能较好地瓜倾吐夺前中短期阶段孕震区及其周围地区地震活动的异常平静及丛集的现象。二参量异常的时空分布图像上示出在中强震发生前3个月至1年在震中周围地区有明显的异常分布,且随着时间逼近发震时  相似文献   

16.
钟贻军 《华南地震》1996,16(4):56-60
1993年8月1日至11月间,广东省连山县发生小展群活动,最大震级为ML3.6级,极震区烈度为Ⅳ度。各次地震震中位置基本上无变化,皆为24.7°N,112.2°E,震源体位于太保花岗岩侵入体中,体积小,约为20~30km3,震源深度较浅,约为5~10km。文章认为,连山小震群活动与华南沿海地区,特别是沿海西部地区的强震活动有一定的联系,但不具备前兆震群的一般特征。  相似文献   

17.
简述了1995年苍山5.2级地震现场布设临时地震台的工作情况,分析了地震序列特征,早期震型判断的基本依据以及后续最大地震的追踪预测。回顾了震前有一定程度的中期预报恬 期有所觉察而临震漏报的过程及原因,并根据地震现场震情监测预报工作所暴露的问题,提出了切实改善和充实仪器装备,加强平时备震技术训练等建议。  相似文献   

18.
通过对印尼苏门答腊岛及其附近1900年以来7.5级以上地震发生后一年内全球7级以上地震强度和分布特征分析,发现此年活动水平一般高于1900年以来的年平均水平,且地震主要发生在太平洋地震带的西段,同时分析了该区域强震对中国大陆及周边地区7级以上地震活动的影响.  相似文献   

19.
    
The North Anatolian fault is a well-defined tectonic feature extending for 1400 km across Northern Turkey. The space-time distribution of seismicity and faulting of this zone has been examined with a particular emphasis on the identification of possible seismic gaps. Results suggest several conclusions with respect to the temporal and spatial distribution of seismicity. First, the earthquake activity appears not to be stationary over time. Periods of high activity in 1850–1900 and 1940 to the present bracket a period of relatively low activity in 1910–39. Second, there appears to have been a two-directional migration of earthquake epicenters away from a central region located at about 39°E longitude. The migration to the west has a higher velocity (>50 km/yr) than the migration to the east (10km/yr). The faulting associated with successive earthquakes generally abuts the previous rupture. Some existing gaps were filled by later earthquakes.At present there are two possible seismic gaps along the North Anatolian fault zone. One is at the western end of the fault, from about 29° to 30°E. Unless this is a region of ongoing aseismic creep, it could be the site of a magnitude 6 or greater earthquake. The other possible gap is at the eastern end, from about 42° to 43°E, to the west of the unexpected M=7.3 event of 24 November 1976.  相似文献   

20.
An attempted use of seismic gap observations to predict a large earthquake in Oaxaca, Mexico is discussed. The observations were initially published in a scientific journal and were subsequently distorted by noncientists, who predicted a major earthquake and tsunami to take place at Pinotepa Nacional, Oaxaca on 23 April 1978. Public reactions and property losess sustained by individuals and communities were comparable to those expected from an actual earthquake. A revision of epicenter locations from the NOAA data file revealed that a number of earthquakes did occur in the alleged gap but had been excluded because their reported focal depth was in excess of 60 km. It is shown that the probability that the number of earthquakes in two consecutive time intervals of a stationary Poisson process differs by an amount which would be reported as a seismic gap is of the order of 5% or more for Oaxaca. This means that spurious seismic gaps would be observed in one out of 20 data runs. The possibility of detecting a true interval of abnormal quiescence in a random earthquake sequence appears to be fairly remote in this case.  相似文献   

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