Gravitational model of the Taiwan lithosphere (along the profile Taiwan Strait-Taiwan Island-West Philippine basin)

Based on two-dimensional gravity modeling, the density section of the lithosphere beneath Taiwan and the surrounding areas is constructed. According to the density parameters, the lithosphere of this region comprises both the continental and oceanic types. The continental lithosphere is lighter than the oceanic one and demonstrates insignificant density differentiation through the entire section. The oceanic lithosphere is more contrasting with respect of both the crust and mantle density. The complicated Taiwan density structure corresponding to Taiwan Island is defined to be superimposed on the transition zone between the continental and oceanic lithospheric blocks. This structure with contrasting density boundaries is characterized by the elevated and high density values of its constituting heterogeneities. The formation of the Taiwan density structure is related to geodynamic processes in the Taiwan area marking the collision zone between the Eurasian and Philippine Sea plates.     

1994年9月16日台湾浅滩7.3级地震发震构造的讨论

从台湾海峡与台湾浅滩的地貌特征、区域构造格局、海峡盆地形成历史、深部构造与断裂构造、震源机制解以及地震活动等方面论述了台湾浅滩７．３级地震的发震构造,认为北东东向澎湖—北港隆起南侧断裂（义竹断裂）是该地震的发震构造。     

地段地理学及其实践意义

地段地理学是以微观尺度的地段研究为对象的现代应用地理学的工程化方向为其基本内涵,通过运用案例对其进一步分析说明,充分表明了地段地理学的实践意义。     

中国旅游企业集团战略联盟的博弈分析

加入WTO后，中国旅游企业面临前所未有的挑战和冲击。为适应经济形式的发展。中国旅游企业中开始大规模的联合、重组和改制。在旅游企业的整合过程中，以战略联盟的形式来实现企业的规模经营是中国旅游企业生存和发展的有效措施之一。在战略联盟过程中，以动态博弈的方法对企业之间的联盟做出及时、有效的分析，可使旅游企业清楚自己在联盟中的地位与得失，最大限度的避免负效应，力争获得最大的经济效益。     

1994年9月16日台湾海峡7.3级地震震源过程的研究

采用数字化台网Ｐ波波形资料及台湾台网Ｐ波初动方向资料,研究了１９９４年９月１６日台湾海峡７３级地震及邻近地区（北纬２１～２６°,东经１１５～１２０°）ＭＬ≥５８级共５次地震的矩张量解及震源参数。结果表明,这次７３级地震的矩张量解以双力偶成分为主,是断层面接近ＮＷ走向的正断层。断层面的走向与大震前地震的条带分布走向及余震分布显示的破裂图象较相象,震源机制的张应力轴接近水平,近ＮＥ走向;压应力轴几乎垂直,近ＮＷＷ走向,似乎表明这次地震是受菲律海板块向欧亚板块北西向挤压的力源控制。从Ｐ轴接近竖直而Ｔ轴接近水平来看,发震断层为强烈拉张性正断层,可能还同时存在垂直向上的应力作用。其它４个强震的震源机制解与７３级大震的差别较大。这些地震震源机制解的复杂性,表明台湾海峡地震序列的发展过程比较复杂。     

Inversion of source process and related studies of the Taiwan Strait earthquake using genetic algorithm

Applying genetic algorithm to inversion of seismic moment tensor solution and using the data of P waveform from digital network and initial motion directions of P waves of Taiwan network stations, we studied the moment tensor solutions and focal parameters of the earthquake of M=7.3 on 16 September of 1994 in Taiwan Strait and other four quakes of M _L≥5.8 in the near region (21°–26°N, 115°–120°E). Among the five earthquakes, the quake of M=7.3 on September 16, 1994 in Taiwan Strait is the strongest one in the southeastern coast area since Nan’ao earthquake of M=7.3 in 1918. The results show that moment tensor solution of M=7.3 earthquake is mainly double-couple component, and is normal fault whose fault plane is near NW. The strike of the fault plane resembles that of the distributive bands of earthquakes before the main event and fracture pattern shown by aftershocks. The tension stress axis of focal mechanism is about horizontal, near in NE strike, the compressive stress axis is approximately vertical, near in NWW strike. It seems that this quake is controlled by the force of Philippine plate’s pressing Eurasian plate in NW direction. But from the viewpoint of P axis of near vertical and T axis of near horizontal, it is a normal fault of strong tensibility. There are relatively big difference between focal mechanism solution of this quake and those of the four other strong quakes. The complexity of source mechanism solution of these quakes represents the complexity of the process of the strait earthquake sequences. Contribution No. 98A01001, Institute of Geophysics, State Seismological Bureau, China. The subject is supported and helped by Academician Yun-Tai CHEN, Profs. Qing-Yao HONG, Zhen-Xing YAO, Tian-Yu ZHENG, Yao-Lin SHI, Ji-An XU, Bo-Shou HUANG and colleague Mei-Jian AN, Xue-Reng DING, Rui-Feng LIU. De-Chong ZHANG and Ming Li provided the digital data warm-heartedly. Lin-Ying WANG offered us the catalogue of earthquakes in southeastern coastal area in China. Xi-Li WANG and Tong-Xia BAI provided us the issued annual reports data. The authors would like to express their gratitude to all of these people. This paper is sponsored by the National Natural Science Foundation of China and Scientific and Technological Commission of Shantou, Guangdong Province.     

Estimation of groundwater recharge using the chloride mass-balance method, Pingtung Plain, Taiwan

 Due to rapid economic growth in the Pingtung Plain of Taiwan, the use of groundwater resources has changed dramatically. Over-pumping of the groundwater reservoir, which lowers hydraulic heads in the aquifers, is not only affecting the coastal area negatively but has serious consequences for agriculture throughout the plain. In order to determine the safe yield of the aquifer underlying the plain, a reliable estimate of groundwater recharge is desirable. In the present study, for the first time, the chloride mass-balance method is adopted to estimate groundwater recharge in the plain. Four sites in the central part were chosen to facilitate the estimations using the ion-chromatograph and Thiessen polygon-weighting methods. Based on the measured and calculated results, in all sites, including the mountain and river boundaries, recharge to the groundwater is probably 15% of the annual rainfall, excluding recharge from additional irrigation water. This information can improve the accuracy of future groundwater-simulation and management models in the plain. Received, April 1996 Revised, March 1997, November 1997 Accepted, March 1998     

台湾海峡毛颚动物分布的初步研究

本文分析了台湾海峡毛颚动物的种类组成、数量分布特征，并就其与环境因素的关系进行了初步探讨．结果显示与台湾海峡西部、东海等邻近海域相比，本区毛颚动物具种数少，数量小，季节变化幅度较小等特点．它的数量分布状况与闽斯沿岸流、南海西南季风漂流以及黑潮支流在本区运动消长有关。     

Intrusion of Kuroshio water onto the continental shelf of the East China Sea

As a fundamental study to evaluate the contribution of the Kuroshio to primary production in the East China Sea (ECS), we investigated the seasonal pattern of the intrusion from the Kuroshio onto the continental shelf of the ECS and the behavior of the intruded Kuroshio water, using the RIAM Ocean Model (RIAMOM). The total intruded volume transport across the 200m isobath line was evaluated as 2.74 Sv in winter and 2.47 Sv in summer, while the intruded transport below 80m was estimated to be 1.32 Sv in winter and 1.64 Sv in summer. Passive tracer experiments revealed that the main intrusion from the Kuroshio to the shelf area of the ECS, shallower than 80m, takes place through the lower layer northeast of Taiwan in summer, with a volume transport of 0.19 Sv. Comparative studies show several components affecting the intrusion of the Kuroshio across the 200 m isobath line. The Kuroshio water intruded less onto the shelf compared with a case without consideration of tide-induced bottom friction, especially northeast of Taiwan. The variations of the transport from the Taiwan Strait and the east of Taiwan have considerable effects on the intrusion of the Kuroshio onto the shelf.     

台湾海峡海表面温度的遥感反演及精度检验

海表面温度(SST)是海洋-大气系统中一个十分关键的物理量。SST为海洋学课题的研究提供了一种直观的指示量[1],在海洋捕捞中SST是寻找中心渔场的指标之一,可为渔业部门提供鱼类的回游路线和渔场的位置信息[2]。SST制约着海面和大气的热量、动量和水汽交换,是研究大气环流和气候变化[3]甚至台风移动路径[4]等气象学课题的一个重要因子。因此,SST在海洋学和气象学研究中占有非常重要的地位,此外SST对海洋运输、海洋污染、海上油气资源开发、海滨核电站建设等方面的影响近年来也倍受关注。