Pb-210 and Po-210, a parent-daughter pair, are particle-reactive radionuclides. Pb-210 tends to be associated with inorganic particles but Po-210 prefers organic particles. In the context of these characteristics the purpose of this study is to determine Po-210 and Pb-210 in the surface water plankton of the northern South China Sea (SCS) and the Luzon Strait (LS) areas in order to understand their temporal and spatial distributions and the extent of their radioactive disequilibrium. As the LS has provided a pathway for the exchange between the Kuroshio and the SCS waters, the study area has the characteristics of an open ocean and a marginal sea. The plankton Po-210 activities in the study area are about 10~400 dpm/g, but may reach 1200dpm/g in an El Nino year, the effect of which on Po-210 is not clear at present. The Po-210 in the plankton is mainly affected by the surface water Po-210 , biomass concentration, and the Po-210 in the surface water as well as plankton transported from other area(s). If the biomass concentration (as indicated by Chlorophyll-a) increases, the Po-210 in the plankton decreases, i.e. they are inversely correlated. Based on the planktonic Po-210 distribution, the Kuroshio water which has both high Po-210 and high Po-210-bearing plankton has evidently intruded into the northern SCS. The Pb-210 activities of in the plankton vary from 5 to 25dpm/g; the variation trend is similar to that of Po-210 but with much lower activity, resulting in a Po-210/Pb-210 ratio much greater than unity. Compared to the suspended particles, the plankton is highly enriched in Po-210 but it strongly repels Pb-210. Based on earlier studies and this one, the extent of Po-210 enrichment (as indicated by the Po-210/Pb-210 activity ratio) in various organisms increases sequentially from plankton to mussel, large swimmer and then to marine fish, i.e. the higher the level of organism in the food chain, the higher the ratio becomes. However, the Po-210 and Pb-210 activities per unit mass of these organisms are generally lower than those of plankton. Organisms of higher food-chain level may accumulate Po-210 in the digestive system, but part of it may be excreted. Po-210 accumulation does not occur in other parts of these organisms. In terms of adsorption, the plankton with greater surface area to volume ratio, can adsorb more Po-210 resulting in a higher specific activity, whereas large organisms with smaller surface area to volume ratio can adsorb less Po-210 yielding a lower specific activity. The enrichment of Po-210 in various organisms must have been achieved by absorption and adsorption with unknown proportion. Based on a simple box model calculation for the northern SCS water within the upper 100m layer, the excess Po-210 in the planktonic biomass can account for about 70% of the total deficit in this layer. But in the LS area, the excess and the deficit are balanced. This suggests that the Po-210 deficit in this surface water is due to absorption and adsorption by organisms as evidenced by their large Po-210 enrichment.

Abstract In this study, we have analyzed systematically the oxygen isotopic compositions of South China Sea (SCS) and Luzon Strait (LS) seawater so that a comprehensive interpretation of their temporary and spatial variability can be delineated. The oxygen isotopic compositions of the samples collected in the two areas were determined using the Epstein-Mayeda technique, and the overall precision of the d18OSMOW measurements is +0.1 ?. Our data suggest that LS seawater is a mixture of SCS and Kuroshio waters. The precipitation (1.5 mm) on SCS in April 1998 (during ORI517 cruise) is much less than that (169.5 mm) in April 1999 (during ORI546 cruise). As LS and SCS waters are concerned, the profiles of d18OSMOW generally share the same trend as those of salinity. The d18OSMOW values of the SCS surface water decrease toward the south, while those of the LS surface water decrease toward the west. These suggest that the effect of the Kuroshio water decreases are it moves from northeast toward southwest after its intrusion through LS. The salinity of Kuroshio water reaches the maximum at 34.92 with the corresponding d18OSMOW value of 0.42 ?, whereas the salinity of the representative SCS surface water is 33.34 and the corresponding d18OSMOW is -0.25 ?. As these two data were selected as end members, the estimated proportion of the intruding Kuroshio water in the composition of LS water could be high up to 80 % at 121.5o E. The plot of d18OSMOW versus salinity for cruises OR517 and 546 shows a difference between the slopes of the two regression lines, indicating the effect of variability in precipitation and the depth of the mixed layer. The average d18OSMOW value for surface water decreases toward the west as the water moves from Western Philippine Sea (WPS) to LS and SCS. The average d18OSMOW values for the surface, subsurface, intermediate, and deep waters are listed in the corresponding order in parentheses preceded by the studied area as follows: WPS (0.29 ?, 0.25 ?, -0.06 ?, -0.10 ?); LS (0.15 ?, 0.17 ?, -0.02 ?, -0.08 ?); SCS (-0.03 ?, 0.18 ?, -0.05 ?, -0.08 ?).

Thesis (Ph. D.)--Yale University, 1979. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 522-527).

Thesis (Ph. D.)--Yale University, 1979. / Typescript. Vita. Includes bibliographical references (leaves 522-527). Also issued in print.

This study analyzed historical hydrographic data consist of 95 years of NODC data and 18 years of NCOR data. Variations of upper-layer current in Luzon Strait and its neighboring Northern South China Sea are investigated by the method of dynamical topography. On the other hand, higher salinity characteristic of the North Pacific Tropical Water (NPTW) is used to trace the water mass distribution and its seasonal variations in the studied area. The result shows that the maximum of x-component velocity (along 120.25˚E, relative to 400 m ) in the Luzon Strait occurs in the middle of the strait, the flow direction is westward and the speed increases toward the surface. At the north and south ends of the strait flows are eastward and the maximum speed core is at the depth of 0~50 m. Horizontal distribution of flow fields indicates that intrusion of the north Pacific waters into the South China Sea through the Luzon Strait in the whole year. Westward bifurcation of the intrusion flows occurs at 20~21˚N. A cyclonic eddy exists in the South China Sea all year-round, and its core is located at about 18˚N, 118˚E. This eddy strengthens as the monsoon prevails with its speed reached in January and February. Annual mean upper-layer transport (0~ 400 m) of the Luzon Strait is estimated to be about 3.5 Sv (positive value means westward) with a maximum value of about 6.5 Sv in December and a minimum value of 1.1 Sv in June. The Upper-layer current of the SCS is dominated by the monsoon. When the northeast monsoon prevails, the currents are affected by the Ekman effect to form high sea surface height in the north and low sea surface height in the south to produce a westward current. On the other hand, strong two coexistent wind stress curls with reversing signs during the northeast monsoon produce a westward current along the line of zero curl in the middle of the strait. The distribution of the NPTW(£m£c=23.5¡ã25.5 kg/m3,S >34.5 psu) is mostly at a depth of 120¡ã130 m in the South China Sea. NPTW were traced at 125 m depth, and the result indicates that this water mass enters the South China Sea through the Luzon strait all year-round. The intrusion path is along the continental slope of south China. The extent of intrusion reaches the maximum between December and February, and the water mass can spread into the South China Sea basin.

This study utilized, for the first time, the d18Osw as a tracer to investigate the seasonal variations of circulation in the Taiwan Strait (TS), which is the predominant sea passage with an average depth of 60 m connecting the East China Sea (ECS) and the South China Sea (SCS). The result shows that the circulation system in TS is mainly influenced by the inter-mixing among the China Coastal Water (CCW), the SCS water (SCSW), and the Kuroshio Water (KW). In spring, the KW dominates in TS, whereas the CCW is still observed in northwest TS. During the summer, SCSW replaces the KW and becomes the major water type in the TS, yet the KW is found to be restricted in the southwest part and the bottom of the TS. Due to the larger discharge from rivers (mainly the Yangtz River), the CCW has a more extensive distribution in the TS in summer than other seasons. In fall and winter, the CCW occupies the northern part of TS due to the stronger northeastern monsoon which limits the intrusion of the KW through the Luzon Strait to the northern TS. The two distinct water types inevitably form a front in the central TS. The hydrographic variations at Penghu Channel (PHC) were also explored in this study. The d18Osw indicates that the perennial intrusion of the KW into the PHC is varying throughout different seasons. This intrusion is found strongest in fall and winter. In summer, the upper layer of PHC is occupied chiefly by SCSW, while the KW remains at the bottom layer in PHC. By including an additional inflow of 0.5Sv from TS to ECS, this study further reconstructed a box model of the ECS, which was previously furnished by Lin(1999). The new estimates suggest that ~0.38*104 km3/year of the Kuroshio surface water (0-50m) and ~1.54*104 km3/year of the upwelled Kuroshio subsurface water (50-150m) are transported to the ECS, while ~3.83*104 km3/year of the ECS water are exported to the western Pacific Ocean.

This project applies statistical inference methods to energy data from the island of Luzon in the Philippines. The goal of the project is to explore different ways of creating predictive models and to understand the assumptions that are made about reality when a certain model is selected. The main models discussed in the project are Simple Linear Regression and Markov Chain Models. The predictions were used to assess Luzon's progress towards the sustainable development goals. All models considered in this project suggest that they are not on target to meet the sustainability goal.

Arc-continent collisions are believed to be an important mechanism for the growth of continents. Taiwan is one of the modern day examples of this process, and as such, it is an ideal natural laboratories to investigate the uncertain behavior of continental crust during collision. The obliquity of collision between the northern South China Sea (SCS) rifted margin and Luzon arc in the Manila trench subduction zone allows for glimpses into different temporal stages of collision at different spatial locations, from the mature mountain-belt in central-northern Taiwan to the 'pre-collision' rifted margin and subduction zone south of Taiwan. Recently acquired seismic reflection and wide-angle seismic refraction data document the crustal-scale structure of the mountain belt through these different stages. These data reveal a wide rifted margin near Taiwan with half-graben rift basins along the continental shelf and a broad distal margin consisting of highly-extended continental crust modified by post-rift magmatism. Magmatic features in the distal margin include sills in the post-rift sediments, intruded crust, and a high-velocity lower crustal layer that likely represents mafic magmatism. Post-rift magmatism may have been induced by thermal erosion of lithospheric mantle following breakup and the onset of seafloor spreading. Geophysical profiles across the early-stage collision offshore southern Taiwan show evidence the thin crust of the distal margin is subducting at the Manila trench and structurally underplating the growing orogenic wedge ahead of the encroaching continental shelf. Subduction of the distal margin may induce a pre-collision flexural response along the continental shelf as suggested by a recently active major rift fault and a geodynamic model of collision. The weak rift faults may be inverted during the subsequent collision with the continental shelf. These findings support a multi-phase collision model where the early growth of the mountain belt is driven in part by underplating of the accretionary prism by crustal blocks from the distal margin. The wedge is subsequently uplift and deformed during a collision with the continental shelf that involves both thin-skinned and thick-skinned structural styles. This model highlights the importance of rifting styles on mountain-building. / text

This manuscript is a study of the Thirty-Third Infantry, United States Volunteers, a regiment that was recruited in Texas, the South, and the Midwest and was trained by officers experienced from the Indian Wars and the Spanish-American War. This regiment served as a front-line infantry unit and then as a constabulary force during the Philippine War from 1899 until 1901. While famous in the United States as a highly effective infantry regiment during the Philippine War, the unit's fame and the lessons that it offered American war planners faded in time and were overlooked in favor of conventional fighting. In addition, the experiences of the men of the regiment belie the argument that the Philippine War was a brutal and racist imperial conflict akin to later interventions such as the Vietnam War. An examination of the Thirty-Third Infantry thus provides valuable context into a war not often studied in the United States and serves as a successful example of a counterinsurgency.