强震孕育后期地震活动演化的定量表征

本文着眼于地震活动总体特征，探讨孕震后期地震活动演化特征，首先引进算法复杂性ＡＣ值与地震危险度Ｄ值两种方法，并定义了地震活动演化值数ＹＨ值。通过对近年来资料齐全的中国东部６．０级以上、西部６．５级以上强震资料的分析，得到地震活动复杂性的ＡＣ减少、ＹＨ值升高、Ｄ值增加是地震孕育后期的重要特征，它们并能定量表片地震活动图象的演化，最后，为了从机理上进一步论证强震后期地震活动特征，我们利用带断层的细胞自     

汾渭带和华北平原带强震活动的群集特征

根据描述地震活动时间间隔统计特征的系数Ｃｖ，汾渭带和华北平原带强震活动（ＭＳ≥７．０和Ｍｓ≥６．０）过程显示出明显的非泊松的群集统计特征（Ｃｖ＞１）；对于自公元５００年以来的Ｍｓ≥７．０大地震活动过程，其累计频度（ΣＮ）表现出满足ｌｎ（ｌｎΣＮ）＝Ａ＋Ｂｔ关系的逐步加速释放能量的群集时间结构；对于自公元１０００年以来的Ｍｓ≥６．０强地震活动过程，则表现出几十年－几百年尺度的密集和平静交替发生的幕式群集时间结构。     

M≥6.0强震后地震序列类型的模糊聚类分析

在充分了解地震序列特征的基础上，选出２６项地震序列的原始特征。根据这些原始特征的Ｗａｌｌｅｎ评分，精选出１１项能突出表现地震序列的特征参数作为指标。采用ＩＳＯＤＡＴＡ模糊聚类方法对地震序列进行分类，Ⅰ类为Ｍ≥６．０强震后三个月内还有震级为Ｍ≥５．０的强震发生；Ⅱ类为Ｍ≥６．０强震后三个月内无Ｍ≥５．０的地震。对中国大陆地区１９６６年以来的２２次Ｍ≥６．０强震序列进行聚类分析，建立预报震后趋势判别模型，然后以８次强震序列为例进行了外推检验。结果表明，该方法对地震序列类型的判别效果较好。     

1932年昌马地震构造力学特征探讨

１９３２年昌马地震构造力学特征探讨郭万武，张范民，邢成起，温增平（国家地震局兰州地震研究所，兰州）ＤＩＳＣＵＳＳＩＯＮＯＮＴＨＥＴＥＣＴＯＮＯＭＥＣＨＡＮＩＣＦＥＡＴＵＲＥＳＯＦ１９３２ＣＨＡＮＧＭＡＥＡＲＴＨＱＵＡＫＥＭｓ７．６￥ＧｕｏＷａｎｗｕ；...     

广东及邻区地震学参量b、η、Dt值与地震的关系

应用ｂ,η和广义时间分维Ｄｔ值的时间扫描计算方法,对广东省及邻区１９７０年以来发生的１５次Ｍｓ≥４．６级地震中周围的小震活动进行单项和综合分析研究,结果表明,震前２个月至１年半内,这三种参量大都存在明显的低值异常过程,与地震的对应率在６９％,表明该组参量可作为本区地震预测的有效判据,利用其综合预测效能,可提取本区地震的中短期异常标志。     

全球大震和中国及邻区中强震地震活动(1999年4～5月)

本目录中的地震参数来自“中国地震台临时报告”（简称“月报”）．其中,国内及邻区给出Ｍ≥４．７的事件,全球给出Ｍ≥６的事件．“月报”由中国地震局地球物理研究所九室按月做出．本目录中的发震时刻采用协调世界时（ＵＴＣ）;为了方便中国读者,也给出北京时（ＢＴＣ）．震中位置除给出经纬度外,还给出参考地区名,它仅用作查阅参考,不包含任何政治意义;还给出测定震源位置的台数（ｎ）和标准偏差（ＳＤ）．面波震级ＭＳ是对中周期宽频带ＳＫ地震仪记录,采用北京台１９６５年面波震级公式ＭＳ＝ｌｇ（ＡＨ／Ｔ）＋１．６６ｌｇ（…     

Ns,K,R,M等值线图所展示的川滇地区强震的前兆图象

充分展示了ＮＳ,Ｋ,Ｒ,Ｍ等值线图的预测效能。这种图定量、直观。利用他捕捉到了一些有效的前兆现象,其中最主要的是：①ＭＳ≥７．０地震前３年震中附近ＭＬ≥３．５地震频数显著增加;②ＭＳ≥７．０地震前１年研究区ＭＬ≥２．０地震频数降半;③ＭＳ≥６．０地震后地震活动数年不衰的地区是未来ＭＳ≥７．０地震发生的可能地点;④孟连—普洱及其附近地区余震中心偏离主震震中逼近未来强震震中;⑤普洱地区地震活动性低,次年发生ＭＳ≥６．０地震的可能性较小。文中用广义地震成核模型对现象①进行了物理解释。     

河南及邻区中等地震前地震活动性异常

采用“八五”地震预报攻关研究成果－－地震算法复杂性Ｃ（ｎ）值及地震强度因子Ｍｆ值时间扫描，对河南及邻区１２次中等以上地震进行单项和综合分析研究。结果表明，对应率达８０％，显示出这些方法具有一定的预报意义。     

中强以上地震发生后半年内地震趋势的模糊聚类分析

利用１次中强以上地震（Ｍ０≥４．７）发生后前６天地震序列的资料，对未来半年内是否可能发生相当（Ｍ＝Ｍ０±０．３）或更大的地震进行模糊聚类分析．根据３６个初选问题的Ｗａｌｌｅｎ评分，精选出１３项能突出表现地震序列的特征参数作为指标．应用模糊聚类的ＦＣＭ算法对地震序列进行分类，Ⅰ类为Ｍ０级中强震后６个月内还有震级为Ｍ≥Ｍ０－０．３级的地震发生；Ⅱ类为Ｍ０级中强震后６个月内无相当或更大的地震。以中国大陆地区１９６６年以来的４８次Ｍ０≥４．７级中强震序列资料建立震后判别模型，然后对近期发生的８次强震序列进行了外推检验。     

北京顺义4.0级地震和震后首都圈地震趋势分析

１９９６年１２月１６日顺义Ｍｓ４．０地震，是北京地区近６ａ来最大的一次地震活动此次地震前，首都圈地区地震活动出现了近ＳＮ向弱震活动，１１月份地震活动是全的月频次最低的月份，这些异常现象之后发生了顺义地震。此次顺义地震属非前生震群活动。这次地震活动是顺义及其附近地区１９７０年以来地震活动余震最多的一次。这次地震后应注意今后几个月京西北、张家口附近发生Ｍｓ５．０左右地震的可能。     

SCIENCE CHINA Earth Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Distribution of throughfall and stemflow in multi‐strata agroforestry,perennial monoculture,fallow and primary forest in central Amazonia,Brazil

The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi‐strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open‐area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open‐area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow. Copyright © 1999 John Wiley & Sons, Ltd.     

A Monte Carlo study of rainfall forecasting with a stochastic model

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.     

Anthropogenic Eutrophication and Red Tide Outbreak in Lacustrine Systems of the Kashmir Himalaya

Red tide, a recurrent phenomenon has become conspicuous in several Kashmir lake ecosystems since 1991. The responsible organism (Euglena pedunculata), a rare flagellate rediscovered in the Kashmir Himalaya (Khan 1993) caused first and unprecedented red tide outbreak, constituting a maximum of 96% of resident numerical phytoplankton density in Dal Lake. At present, conflicting hypotheses exist on the generation of causal assemblage(s) imparting redness to waters: Jeeji Bai (1991) linked its origin to acid precipitation – a fallout of burning oil‐fields during the Gulf War – whilst Khan (1993) holds local factor(s) responsible. Field/experimental studies support the latter contention that the influx of untreated sewage, in unison with warm temperatures, high levels of PhAR, iron and interruption to hydrological flow‐pattern together with absence/or reduction in grazing activity created conducive environmental milieu for red tide outbreak. Dal Lake “red tide” drifted the bloom‐inoculum to other waters, including Lake Wular, where additional ecological niches were carved out, threatening the aesthetic value and biological diversity of Kashmir lakes. Ecological monitoring indicates frequent seasonal red tide occurrence in Dal Lake (including summer‐autumn event of 1998) which testifies its unabated eutrophication status. Further studies are needed on ecological adaptability and biogeographic distribution of this rare and unique red tide‐causing flagellate.