南黄海前新生代油气地球物理勘探方法

南黄海前新生代地层为中-古生代大套碳酸盐岩夹碎屑岩,具有较好的油气前景。由于该领域地质、地球物理的复杂性,勘探难度较大。论述了南黄海前新生代油气地球物理勘探的难点和重点,在理论研究的基础上,提出了地球物理勘探的技术方法及实践效果。     

Seasonal cycle of topography in the Bohai Sea and Yellow Sea and its relationships with atmospheric forcing and oceanic adjustment based on altimetry data

Seasonal cycle is the most significant signals of topography and circulation in the Bohai Sea (BS)and Yellow Sea (YS) forced by prevailing monsoon and is still poorly understood due to lack of data in their interiors. In the present study, seasonal cycles of topography in the BS and YS and its relationship with atmospheric forcing and oceanic adjustment were examined and discussed using TOPEX/Poseidon and ERS-I/2 Sea Level Anomalies (SLA) data. Analyses revealed complicated seasonal cycles of topography composed mainly of 2 REOF modes, the winter-summer mode (WlM) and spring-autumn mode (SAM). The WlM with action center in the BS displayed peak and southward pressure gradient in July, and valley and northward pressure gradient in January, which is obviously the direct response to monsoon with about l-month response time. The SAM with action center in the western south YS displayed peak and northward pressure gradient in October and valley and southward pressure gradient in April. After the mature period of monsoon, the action center in the BS becam eweakened while that in the western south YS became strengthened because of regional convergence or divergence induced by seasonal variations of the Taiwan Warm Current and Yellow Sea Coastal Current. The direct response of topography to monsoon resulted in the WIM, while oceanic adjustment of topography played an important role in the forming of the SAM.     

Interannual variability of the southern Yellow Sea Cold Water Mass

Temperature data collected in the sections of 34°N, 35°N and 36°N in August from 1975 through 2003 were analyzed using Empirical Orthogonal Function (EOF) to investigate interannual variability of the southern Yellow Sea Cold Water Mass (YSCWM). The first mode (EOF1) reveals variations of basin-wide thermocline depth, which is mainly caused by surface heating. The second mode (EOF2) presents fluctuations of vertical circulation, resulting mainly from interannual variability of cold front intensity. In addition, it is found that the upward extent of upwelling in the cold front is basically determined by wind stress curl and the zonal position of the warm water center in the southern Yellow Sea is correlated with spatial difference of net heat flux.     

南黄海5.1级地震及趋势分析

１９９７的７月２８日南黄海发生５．１级地震,通过对５．１级地震序列分析,认为此次地震属于前－主－余震型地震充列。文中对５．１级地震前某些地震学异常进行了研究,结果表明：主城前存在中等地震活动集中,地震空区、低ｂ值、地震应变释放加速等特点。结合５．１级地震的发生,对今后地震活动趋势进行了讨论,认为在研究区仍存在６级左右的地震的背景性异常。     

宁波台记录长江口以东南黄海地震震相分析

通过对宁波台记录１９９６年１１月９日长江口以东,南黄海Ｍｓ６．１地夺以及两次较强余震的震相分析,认为短周期记录仪大部分出格后,可用＾－Ｐ－Ｐｎ一段来分析计算震中距和方位角。最好使用符合当地的走时表,这样分析计算结果更符合实际。另外,认为有康腊界面的绕射波Ｐ＾＊的出现是长江口、南黄海一带地震记录的重要特征之一。宁波台记录该区域地城的震相出现顺序为：Ｐｎ、Ｐ＾＊、＾－Ｐ、Ｓｎ、＾－Ｓ,较难分辨,振幅比     

干支60周期及可公度性与江苏—南黄海地区地震预测

根据１５００年以来的地震资料分析,江苏－南黄海地区Ｍ≥５中强震具有显著的干支６０周期性特征,南黄海海域Ｍ≥６强震具有良好的可公度性,并对其基本结构和预测功能进行了研究。未来几年该区依然存在５￣６级地震的危险性,第二活跃幕可能将持续到２００９年前后。     

长江中下游—南黄海地震带地震活动趋势分析

对长江中下游－南黄海地震带地震活跃期,幕划分及其发展趋势进行了研究,对江苏及其邻区今后几年地地震在形势及重点危险区进行了判定,分析认为：长南带从１９７１年以来进入第二活跃期的第３幕,该幕地质活动将持续到２０１０年前后,最高活动水平为６．５级左右,今后几年江苏东部至南黄海海域发生５－６级或６级以上地震的可能性较大。