夏季青藏高原热力场和环流场的诊断分析 Ⅰ.盛夏高原西部地区的水汽状况   总被引：2，自引：0，他引：2  

杨伟愚  叶笃正  吴国雄 《大气科学》1992,(1)

本文使用青藏高原气象科学实验测站观测资料、欧洲中心FGGE-Ⅲb资料、GMS1地球同步卫星云图资料、河流水文资料以及其他一些有关的资料,详细分析了1979年7月青藏高原地区,尤其是高原西部地区的水汽状况、水汽输入的通道,讨论了夏季青藏高原地区高湿状况的维持机制. 通过研究,发现在1979年盛夏青藏高原西部也是一个高水汽区域,有利于大量的湿对流系统活动,但西部比东南部的水汽含量要略低些;潜热加热是夏季高原西部重要的热源之一;除了过去已知的在高原东南和仲巴、定日一带的两条水汽通道外,水汽还可从高原西侧边界进入高原西部.在讨论夏季高原地区高湿状况的维持机制时发现,相对于高原东部,只需要较少的水汽输入就足以维持高原西部大气的高湿状态;高原西部的降水、蒸发和向土壤中渗透是接近于平衡的,水分循环主要是局地的内循环.  相似文献   

PNA流型的年际变化及温、热带太平洋海温的作用   总被引：3，自引：0，他引：3  

吴仁广  陈烈庭 《大气科学》1992,16(5):583-591

本文分析了PNA型环流的年际变化和影响因子,发现它存在两种优势周期振荡:一种是3—5年的振荡,另一种是10年左右的振荡.研究表明,前者与赤道太平洋海温的主要振荡周期相对应(同相关系),后者与北太平洋海温的主要振荡周期一致(反相关系).揭示了PNA型环流的变化与北太平洋海温比与赤道太平洋海温具有更密切的联系.并且由于北太平洋海温影响的频带与赤道太平洋海温的不同,它的作用有时与赤道太平洋海温的同相,有时则反相,使得ENSO与太平洋-北美地区大气环流和气候异常的关系变得复杂化.指出当考虑北太平洋海温的共同作用后  相似文献   

晋陕豫交界区地震活动性分析     

吴富春  姚兆瑞  曾鸣 《山西地震》1992,(4)

分析了晋陕豫交界区临汾、渭南地区的地震活动性,认为自1800年以来,运城地区地震活动明显增强,且有向韩城扩散的趋势  相似文献   

The experimental study of acoustic emission during creep of rocks     

Peiling Lü  Kaitong Wu  Yuanbi Jiao  Jihan Li  Xiaohong Liu 《地震学报(英文版)》1992,5(1):169-176

Under normal temperature, the creep experiments with complete samples of Gabbro and Marble rocks are made under uniaxial compression. It is found that at the instantaneous creeping stage, AE activities increase with loading; at the steady creeping stage, large AE signals may appear at lower background of AE action, andm—value which shows the relationship between AE amplitude and frequency keeps stable on the low value or decreases; at the accelerate creeping stage, AE activities increase andm—value decreases quickly or decreases again after recovery. These experimental results are related to the quality of the samples. In this paper, AE activities during three stages of creeping process are connected with the seismic patterns (for exampleb—value, foreshocks). Finally, it is pointed out the possibility that the foreshock—mainshock—aftershock earthquake sequence has been formed by the mechanism of creep fracture of crustal rocks. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 104–112, 1991. This subject is sponsored by the Chinese Joint Seismological Science Foundation.  相似文献   

油气运移研究新进展   总被引：1，自引：0，他引：1  

吴因业 《地球科学进展》1992,7(6):51-55

综述了油气运移研究的新进展，其主要表现在以下几个方面:1)初次运移研究;2)运移量和运移时间;3)流体三势分析;4)油气形成运移的数学模拟;5)流体封存箱和油气运移
聚集;6)成岩作用体来与油气运移关系的研究。  相似文献   

江西德安宝山锑金矿成矿物理化学条件研究          下载免费PDF全文

吴启志  张景荣  陈云天  汤坤贤 《地质找矿论丛》1992,7(4):35-42

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Moment tensor inversion of some aftershocks of the April 18, 1985 Luquan earthquake of Yunnan Province, China     

Jiangchuan Ni  Yuntai Chen  Ming Wang  Mingxi Wu  Jiayu Zhou  Peide Wang  Francis T. Wu 《地震学报(英文版)》1992,5(3):459-467

Based on the three component accelerograms, recorded at near-field distance by a temporary seismic network consisting of digital cassette tape recording accelerographs, the focal mechanisms of three aftershocks of the April 18, 1985, Luquan, Yunnan Province, China, earthquake ofM _S=6.1, are calculated using seismic moment tensor inversion technique. The phases of direct P, S and converted SP waves in the displacement seismograms, produced by twice integrations of the observed accelerograms, are identified via forward calculation using Green’s functions for homogeneous semi-infinite elastic medium, and used in the inversion. The results of inversion show that a better fit of synthetic to the observed seismograms of direct as well as converted phases can be achieved if appropriate weighting functions are used in solving the over definite linear equations. While these aftershocks are of different magnitudes (M _L=4.8, 3.2 and 3.5, respectively) and hypocentral locations, their focal mechanisms are very similar and consistent with that of the main shock. This feature demonstrates the intrinsic correlation between the occurrence of aftershocks and the seismogenic fault of main shock. Our experimentations show that using the near field accelerogram obtained from the digital seismic network with appropriate azimuthal coverage on the focal sphere, with the aid of even simple medium model, not only the shear dislocation source, but also the isotropic part and CLVD (compensated linear vector dipole) can be retrieved by the technique of moment tensor inversion. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 412–419, 1991. This work is supported by the Chinese Joint Seismological Sciences Foundation and the Western Yunnan Earthquake Prediction Test Site (WYEPTS), State Seismological Bureau.  相似文献   

1991年7月云南施甸5.0,5.2级地震的预报与对策     

吴志平  李敏 《地震研究》1992,15(4):345-354

1991年7月1日、22日在云南省施甸太平乡先后发生了5.0、5.2级两次中强地震。保山行署地震局曾在震前作出了正确的中、短期预报和震后作了无震预报。本文客观地提供了这次地震前后预报的科学依据、中短期自适应加权定量综合判定模式实际计算结果及一系列对策的实况;同时讨论了孕震区内短临阶段前兆变化的异常特征。  相似文献   

金川铜镍硫化矿床成矿温度压力计算及成矿机制探讨     

吴志勇  郭原生  孙淑荣 《矿物岩石》1992,(1)

本文利用橄榄石温度计、压力计的方法,计算金川超基性岩体主要含矿岩相成岩的温度压力条件。根据计算所得的温压数据、矿石结构特征、含矿岩相的相互接触关系及储量分布,判断矿床成因主要属于深部熔集型,并根据不可逆过程热力学平衡扩散方程,探讨硫化物(Ni~(2+),S~(2-))和硅酸盐熔浆(Si_4~(4-))产生熔集的机制。  相似文献   

金矿化探异常定量评价的研究     

吴锡生 《吉林大学学报(地球科学版)》1992,(3)

本文应用RESMA系统对区域化探金异常进行了筛选评价,并对筛选出的异常应用二维地球化学剖面延拓推测其深部的含矿性及预测其远景储量.  相似文献