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1.
苏鲁交界及南黄海地区地震波速比的变化特征 总被引：2，自引：0，他引：2
本文主要应用多台波速比和单台波速比的方法，计算了苏鲁交界及南黄海（北纬３５°３５′至３６°００′，东经１１７°００′至１２１°００′）范围内，１９８４到１９９１年７月发生在该区域的１６３次ＭＬ≥１．７地震的波速比值，并对波速比结果进行ｔ检验和模糊数学分析识别。分析结果发现，１９８５年１月至１１月出现了不连续的波速比低值异常时段，模糊数学识别的异常从属函数在这段时间也呈现高值。异常恢复后，１９８７年 相似文献
2.
大同—阳高地震前后地震波速比在源区与场区的变化特征 总被引：2，自引：1，他引：1
计算了１９８５年至１９９２年发生在ψＮ３９°００‘￣ψＮ４１°００’,λＥ１１２°００‘￣λＥ１１４°３０’范围内的１２７次ＭＬ≥２．０地震的波速比值,分析了１９８０年大同一阳高６．１级地震前后源区与场区波速比的时空变化特征及其差异,对计算结果进行了ｔ检验,源区与场区波速比的时空变化及ｔ检验结果表明,大同－阳高６．１级地震前,源区波速比存在比较明显的下降－－低值－恢复－恢复－高值过程。场区测表现也 相似文献
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本文叙述了地震活动的综合概率预报方法，并对宁夏及青海地区（３５°００’－４１°００’Ｎ，１００°００’－１０７°４０’Ｅ）１９７０年以来的地震活动资料进行了统计计算，对１９９２年－１９９３年该区地震活动进行了综合预报效能检验。并据此对该区１９９４年－１９９５年的地震趋势做了估计。 相似文献
4.
计算了１９７９—１９８７年发生在北纬３４°３０＇一３６°＇１０，东经１１５°—１１７°４５＇范围内１４８次ＭＬ≥２０级地震的波速比值，分析了１９８３年菏泽５．９级地震前后源区与场区波速比的时空变化特征及其差异，对计算结果进行了ｔ检验，源区和场区波速比的时空变化及ｔ检验结果表明，５．９级地震前，源区波速比存在比较明显的下降一低值一恢复过程。场区则表现了５．９级地震临震前的低值异常。５．９级地震后源区和场区的波速比计算结果一致，时空变化均为正常。 相似文献
5.
张北6.2级地震前后地震波速比在源区与场区的变化特征 总被引：3，自引：2，他引：3
计算了 1 991年～ 1 999年发生在北纬 3 9°0 0′～ 42°0 0′,东经 1 1 2°3 0′～ 1 1 6°0 0′范围内的ML≥ 2 .0级地震的波速比 ,分析了张北 6 .2级地震前后源区与场区波速比的时空变化特征及其差异 ,发现 6 .2级地震前源区和场区波速比在时间分布上都出现较明显的低值异常 :下降—低值—平静—恢复—发震过程。在空间分布上低值异常比较集中和同步。对计算结果进行了 t检验 ,源区与场区波速比的时空变化及 t检验表明 6 .2级地震前源区与场区波速比异常非常明显 ,场区 1 995年开始出现波速比在正负之间比较大的变化后持续低值。 6 .2级地震后源区和场区的波速比计算结果一致 ,时空变化均为正常 相似文献
6.
本文阐述了１９９３年１０月２６日青海托来６．０级地震前河西祁连山中西部的波连比异常并进一步讨论了中短期预报指标。通过托来地震研究得到，波速比低值集中区边缘与低波速比异常值地震条带交汇区可能为未来主震位置，波速比低值在多次中强震后仍然继续异常以及波速比在震前１─６个月显著回升可分别作为较强地震趋势异常和地震发生的短期指标。 相似文献
7.
安徽及邻区平均波速比的测定及研究 总被引：6，自引：1，他引：5
将安徽及邻区(29°~36°N,114°~124°E),按1°×1°分成70个区,依据中国地震局分析预报中心编制的1998年1月1日至2003年12月31日全国地震月报目录,采用单事件多台观测资料,在所分区域里进行平均波速比值的计算,结果在其空间分布图像中显示了一定的特征。这些特征可能与地质构造环境即地质构造所形成的断裂带两侧的介质特性差异有关。计算所得的各区平均波速比对以后波速比值的变化分析有一定的参考作用。 相似文献
8.
以内蒙古地震监测台网的监测能力和资料完整性为基础,结合内蒙古东部地区（41°～51°N,114.5°～124.6°E）实际地震地质构造特点,选取了内蒙古东部地区（41°～51°N,114.5 ° ～ 124.6°E） 2008-2012年的ML≥2.0地震作为研究对象,利用多台和达法计算得出了该区域的平均波速比及其变化特征.通过分析该地区两次中等地震震例,发现内蒙古东部地区在中等地震前后波速比时间变化存在显著异常,符合“下降—低值—恢复—发震”的规律,且存在着震后异常期的变化;在对该区域内波速比绘制空间等值线后,发现该区域内波速比高值主要是沿着大兴安岭分布,其空间分布基本呈现东低西高、北低南高的态势.综合研究了区域地震地质背景和最近一两年研究区域内波速比变化,得出内蒙古东部地区地下介质的应力变化比较显著,具备发生中强地震的地质构造条件. 相似文献
9.
根据中国地震局分析预报中心提供的资料 ,2 0 0 1年 9月华北地区 ( 3 3 .0°～ 42 .0°N,1 1 1 .0°～1 2 5.0°E)共发生 ML≥ 3 .0地震 7次 (见表 1 ) ,1 9日 1 6时 0 7分渤海 ML4.7地震是本月最显著的事件。本月地震频度与上月基本持平。参考 1 992年以来的月平均地震频次 ,9月处于中等水平 ,地震活动月能量释放也处于中等偏高状态。震中相对集中在 1 1 9°E以东地区及渤海、黄海海域和山西地震带。表 1 2 0 0 1年 9月华北地区 ML≥ 3.0地震序号发 震 时 刻 年月日时分秒 震中位置φN/° λE/°震级ML震 中0 12 0… 相似文献
10.
１９９３年８月份华北的Ｍ＿Ｌ≥３．０地震华北地区（３３°—４２°Ｎ，１１１°—１２５°Ｅ）１９９３年８月共发生９次的Ｍ＿Ｌ≥３．０地震，其中最显著的事件是１９９３年８月３０日大同发生的Ｍ＿Ｌ４．１地震。继上月山西带南端曲沃地区发生Ｍ＿Ｌ４．１地震后，... 相似文献
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M. N. French R. L. Bras W. F. Krajewski 《Stochastic Environmental Research and Risk Assessment (SERRA)》1992,6(1):27-45
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities. 相似文献
14.
《地震工程与工程振动(英文版)》2014,(4)
正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and 相似文献
15.
George W. Housner 《地震工程与工程振动(英文版)》2008,7(2):I0001-I0001
Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States. 相似文献
16.
《国际泥沙研究》2014,(4)
正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study 相似文献
19.
JianCheng Shi 《中国科学:地球科学(英文版)》2014,57(10):2281-2282
正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases 相似文献
20.
Dissolved total carbohydrates (DTCH), dissolved free monosaccharides (DFMS), dissolved organic carbon (DOC), biodegradable DOC (BDOC), and humic substances (HS) were measured in White Clay Creek (WCC), a stream in southeastern Pennsylvania Piedmont, USA. Samples were collected over different seasons and under baseflow and stormflow conditions. DOC concentrations ranged from 1.0 to 12.8 mg/L C with the highest concentrations associated with stormflows. Carbohydrates ranged from 0.42 to 12.4 μM and accounted for 2.9 to 12.7% of the DOC. Humic substances represented the major DOC fraction, accounting for 55 to 72% of the DOC pool under all flow conditions. The humic fraction had a lower carbohydrate content (4.4%) than the non-humic fraction of DOC (7.2%). Stormflow DOC was enriched in carbohydrates relative to baseflow DOC, but the percentage of humic-C changed little. Carbohydrates were primarily present as dissolved polysaccharides (55%), but a significant fraction was bound to humic substances (40%), while a small proportion was present as monosaccharides (5%). The major monosaccharides in stream water, listed in order of decreasing concentration, included glucose, galactose, rhamnose, xylose, arabinose, mannose, and fucose. On average (30.6 ± 7.4)% (n = 44) of the stream water DOC was biodegradable, and carbohydrates accounted for 9.9 to 17.7% of the BDOC. 相似文献