南海东部俯冲洋脊区段地震静态库伦应力分析

根据对马尼拉海沟及其邻区地震分布和震源机制解所反映的最大主压应力轴分布特征的分析,并结合古洋脊俯冲区段地震产生的静态库伦应力分析,发现在马尼拉海沟区域地震分布具有明显的分带特性,北部以NW向挤压应力为主,俯冲洋脊区段以近EW向的挤压应力为主;1999年7.2级地震使得2000年6.2级地震和2011年6.0级地震震中位置的静态库伦应力分别增加了约0.5和0.3 bar;2011年6.0级正断型地震和5.0级余震的静态库伦应力变化能较好地反映与余震分布的对应关系,大部分余震位于库伦应力变化值大于0.1 bar的触发阈值区域;计算古洋脊俯冲区段强震产生的静态库伦应力变化,结果显示海沟西侧小于10 km的深度范围内库伦应力增加值达到0.3~0.5 bar,呈NE向展布,吕宋岛弧一侧20 km深度范围内均表现为应力增加,应力增加区域与地震的分布较为吻合。     

南海东北部陆缘区新近纪早期反转构造特征及其动力学意义

通过深入分析"九七三"项目所获取的高分辨率多道地震剖面,结合区域钻井资料,探讨了新生代以来南海东北部陆缘所历经的新生代早期张裂、中新世晚期阶段性挤压及上新世以来的稳定热沉降等复杂构造运动;张裂背景下的南海东北部陆缘在中新统中部、下部出现的背斜、逆断层等典型压性反转构造,凸现了南海东北部陆缘在晚中新世发生的阶段性挤压构造运动;分析表明,此构造活动是东沙运动在台西南海域的表现,其动力来源同菲律宾海板块的北西向运动有关。     

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马尼拉海湾和莱城港湾的辐射状况

本文利用在马尼拉海湾和莱城港湾考察所获得的少量辐射资料,分析了该两地区辐射各量值的日变化特征和地区差异。揭示了海(港)湾水面及其紧邻海岛陆面的辐射特征差异。这些信息很可能有助于上述地区海洋大气间热量交换的分析计算。     

Vertical zonation and aggregated distribution of the Manila clam on subtidal sand flats in a coastal brackish lagoon along the Sea of Japan

The Manila clam, Ruditapes philippinarum, has maintained small‐sized populations in a semi‐enclosed brackish lake along the Sea of Japan, the Honjo area of Lake Nakaumi, although the environment and biota of this area have changed dramatically due to a large‐scale reclamation project. There should be underlying processes that enable the restoration of this species from small‐sized populations, such as the existence of source (i.e. reproductive) populations in other areas and depth zones of the lake. However, there has been no robust, properly designed evaluation of the distribution of the Manila clam in the subtidal sand flats. In order to elucidate the possible mechanisms that allow for the persistence of populations of the Manila clam, we examined the spatiotemporal and vertical variation in distributions of 0‐age clams in the subtidal zone of sand flats. Seasonal effects on population variations showed erratic changes among depth zones without a decreasing trend along the depth gradient. Further, many local populations became extinct even in the shallower zones due to seasonal (summer) hypoxia at deeper zones and hypoxia by the accumulation of key benthic species (Asian mussel and decaying macroalgae) in mats at shallower zones. A few surviving local populations were stable with a spatial‐fragmental (patchy) distribution, associated with fragmented accumulations of Asian mussels and macroalgae. Efforts to maintain stable populations and to restore this species in the subtidal area may depend on these small, restricted, patchy local populations. These findings suggest that high fertility and productivity of the Manila clam as well as patchy distribution of small populations may contribute to the maintenance of the population and the avoidance of extinction (by spatially diffusing the risk of extinction) in harsh environments resulting from the reclamation project.     

The speciation of dissolved copper,cadmium and zinc in Manila Bay,Philippines

At present, there is a very limited information on the levels and distribution of dissolved metals in Manila Bay. In this study, the horizontal and vertical distribution of operationally defined species (labile, bound and total) of dissolved copper (Cu), cadmium (Cd) and zinc (Zn) were determined using differential pulse anodic and cathodic stripping voltammetry in water samples obtained from 18 stations in November 1998. In addition, the 24-h variability in the concentrations of these species at different depths in the water column was determined. These measurements were complemented by the determination of temperature, salinity, dissolved oxygen, chlorophyll a, particulate organic carbon and nutrients. Results showed that more than 50% of total dissolved copper and cadmium were labile while 50% of total dissolved zinc was organically bound. Vertical profiles showed that Cu, Cd and Zn concentrations were generally high at the surface. Zinc and cadmium were characterised by the presence of a mid-depth minimum while copper did not show any clear vertical trend.

Dissolved Cu concentrations during the spatial and diurnal samplings ranged from 0.32 to 6.95 nM and 1.52 to 45.65 nM, respectively. For Cd, the concentrations in 18 stations ranged from 0.05 to 2.92 nM, and from 0.03 to 2.42 nM over a 24-h period. Zn concentrations ranged from 2.48 to 147.43 nM and 2.87 to 88.27 nM during the spatial and diurnal samplings, respectively. The large variation in the concentration of Cu, Cd and Zn in the bay was observed to be associated with the presence of a large vertical density gradient in the water column, which appeared to limit the exchange of materials between the surface and bottom waters. Elevated levels of these metals near point sources suggest anthropogenic inputs in the bay.     

马尼拉俯冲带中段增生楔精细构造特征及微型圈闭盆地发育模式探讨

对马尼拉俯冲带中段高精度地形数据编辑后绘制成图,联合之前所获取的地震剖面数据,对俯冲带增生楔的精细构造地貌特征及发育模式进行了深入探讨.在增生楔下构造区发现了大量狭长的微型圈闭盆地,经过对其平面断裂特点与深部应力状态的分析,发现增生楔从俯冲前缘到脊顶区其构造特点的转变对应着微型圈闭盆地4个完整的发育阶段,即初期的加积断裂阶段、中期的圈闭成盆阶段、后期的挤压消亡阶段乃至最终的隆升推覆阶段,揭示出一种新型的俯冲带增生楔发育模式,并推断其本质是深部板片俯冲活动所产生的压应力在海底面的表现.     

Whether human-induced activities could change the gradient pattern of coastal land use along the sea-land direction: a case study in Manila Bay,Philippines

Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues. However, whether human-induced activities could change the coastal land use gradient pattern, an important coastal zonal characteristic along the sea–land direction, remains unclear. Manila Bay was selected as the study area in this work. According to the distance of the land use and land cover(LULC) to the coastline, we clustered the typical coastal land use sequence patterns(CLU...     

马尼拉地震带海啸对广东沿海影响的数值研究——潮汐与海啸的非线性作用的影响

基于COMCOT数值模型,建立了天文潮与海啸耦合数学模型,对日本"311"海啸进行了模拟验证。针对马尼拉地震带海啸,通过设计海啸震源的计算,分析广东省沿海海啸风险,从数值上得出了海啸引发的最大增水值以及海啸到达广东省沿岸的时间。     

Global Cities and Circuits of Global Labor: The Case of Manila,Philippines

The ‘global city’ concept has captured the attention of geographers and other social scientists. Research focuses predominantly on capital mobility and the important managerial role exerted by cities in the ‘developed’ realm (i.e., New York, London, Tokyo). The mobility of labor is also important and yet has been neither critically conceptualized nor sufficiently analyzed in existing studies of global cities. Using the Philippines as a case study, I examine 1) how global circuits of labor are socially organized, and 2) the extent to which this social organization is spatially concentrated in Manila. In so doing, I reaffirm the critical role played by Third World cities as global cities.