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2. Cultural Diplomacy in International Relations — A Case Study of Vietnam–India Diplomatic Relation Since Their Strategic Partnership.
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CULTURAL diplomacy , *INTERNATIONAL relations , *BILATERAL trade , *CULTURAL relations - Abstract
Vietnam and India became exceptional friends in the context of globalization and global and regional security in the Indo-Pacific Ocean. India paid a significant consideration to South East Asia and expanded its role in this region in the early 21st century. Meanwhile, Vietnam is one country that experienced a thriving economy in its international and regional integrations. This country has a pressing demand for bilateral and multilateral cooperation with all countries in the world. Especially, the objective of rising India's soft power along with its hard power contributed to promoting India's benefits and involvement in Southeast Asia and Vietnam. Likewise, Vietnam has been fully aware of India's intervention in disputes in the South China Sea and its well-meaning plans to tighten relations with Vietnam over various fields. Vietnam considered India as a partner to conduct Vietnam's soft power. Since Strategic Partnership (2007), Vietnam has accelerated this relation through cultural exchanges, cultural projects, and shared values of Indian culture. Thus, the image of Vietnam becomes familiar to Indian people. Likewise, India encouraged Vietnam to hold cultural events and academic seminars to exchange ideologies, opinions, and plans for many domains. Vietnam is also a goal of India's soft power in Southeast Asia. This paper aims to examine cultural diplomacy in Vietnam's foreign policy in Vietnam–India diplomatic relations mainly based on theories of Liberalism, public diplomacy, and soft power. Thus, it clarifies cultural diplomacy in Vietnam and India's foreign policy. Finally, the author would like to anticipate the scenario of Vietnam–India cultural diplomacy in the future. [ABSTRACT FROM AUTHOR]
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- 2022
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3. Bumping, precedents, and de‐escalation in South China Sea: Options for the United States and China.
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Vuković, Siniša and Alfieri, Riccardo
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SOVEREIGNTY , *CONFLICT management - Abstract
Abstract: The article departs from a much needed clarification about the 2 overlapping conflicts in South China Sea: sovereignty dispute between China and ASEAN countries, and freedom of navigation dispute between China and the United States. Although both are well documented and covered by an extensive range of academic and policy‐relevant analyses, the lines between the 2 have often been blurred, yielding a very limited set of options for proper conflict management. This paper looks at the actual reasons behind Chinese defiance toward the United States, and how can this be reversed. In order to avoid a potential clash in the South China Sea, this paper looks at how similar situations, where the United States was challenging the excessive maritime claims of other nuclear powers, were managed peacefully in light of an inevitable clash. A surprisingly underscrutinized precedent of “bumping incident” form 1988, when U.S. Navy vessels were rammed by Soviet ships and “bumped” back to the international waters is used as a template for a potential solution in the ongoing Sino‐American conflict. This paper examines the limits and opportunities of this type of solution and shows how another “bumping incident” does not need to happen before a bilateral solution is explored. [ABSTRACT FROM AUTHOR]
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- 2018
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4. Sedimentary evolution and controlling factors of Early-Mid Miocene Deltaic systems in the Northern Pearl River Mouth Basin, South China Sea.
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Wang, Yanru, Lin, Changsong, Zhang, Zhongtao, Zhang, Bo, and Liu, Hanyao
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GAS reservoirs , *RIVER sediments , *GRAIN size , *DELTAS - Abstract
The Pearl River Mouth Basin is located at the northern continental shelf of the South China Sea. Since the early Miocene, the Paleo-pearl river transported a large amount of sediments to the northwest of the basin and resulted in the formation of a large-scale river-delta depositional system, which has become an important oil and gas reservoir in the study area. In the current paper, we investigate the characteristics and evolution of fluvial-deltaic depositional systems and their controlling factors, including sea level change, tectonic subsidence and sediment supply on the basis of 3D seismic, well logging and core data. Early-Mid Miocene succession can be divided into two second-order sequences (CS1–CS2) and eight third-order sequences (S1–S8). Deltaic systems developed in S1–S2 are relatively coarse in grain size, and the delta plain deposits are dominated by thickly stacked (100–180 m) distributary channel sand bodies and interpreted as braided delta depositional system. In the early stage (S1–S2), the braided delta systems mainly distributed in the west of the Baiyun Sag, which were proceeded by a retreat to the south of the Enping Sag along with sharply rising sea level. Following the transgression of S2, the provenance of the Paleo-Pearl River extended to the coastal region of South China, and the papleoclimate changed from warm and humid to dry and cold in the early Miocene, leading to the development of transition of braided river delta to meandering river delta, which was characterized by relatively fine grain deposits. During the deposition of S3–S6, well sorted and rounded fine sandstones of deltaic front deposits accumulated in the study area. The retrogradation to accretion and subsequent progradation of these meander delta systems are attributed to the sea level change in the study area. During the deposition of S7–S8, the delta front retreated to the south of the Enping depression as a result of minor sea level rise, reduction in sediment input, and subsidence rate. This resulted in the development of a wave-controlled deltaic depositional system. [ABSTRACT FROM AUTHOR]
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- 2021
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5. China Issues White Paper on Settling Disputes with the Philippines.
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BOUNDARY disputes , *ECONOMIC zones (Law of the sea) , *INTERNATIONAL law , *INTERNATIONAL relations ,UNITED Nations Convention on the Law of the Sea (1982) - Abstract
The article reports the move by the government of China on July 13, 2016 to issue a white paper presenting its position on how to resolve its territorial dispute with the Philippines. Based on the document issued by China's State Council Information Office, the Philippines' claims are groundless under either history or international law. The paper also claimed that the Philippines has abused the United Nations Convention on the Law of the Sea (UNCLOS) dispute settlement process.
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- 2016
6. Wind Profiles and Wave Spectra for Potential Wind Farms in South China Sea. Part I: Wind Speed Profile Model.
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Yichao Liu, Daoyi Chen, Qian Yi, and Sunwei Li
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WIND power , *ENERGY harvesting , *TERRITORIAL waters , *OFFSHORE wind power plants - Abstract
With the setting of wind energy harvesting moving from coastal waters to deep waters, the South China Sea has been deemed to offer great potential for the construction of floating wind farms thanks to the abundance of wind energy resources. An engineering model describing the wind profiles and wave spectra specific to the South China Sea conditions, which is the precondition for offshore wind farm construction, has, however, not yet been proposed. In the present study, a series of numerical simulations have been conducted using the Weather Forecast and Research model. Through analyzing the wind and wave information extracted from the numerical simulation results, engineering models to calculate vertical profiles of wind speeds and wave spectra have been postulated. While the present paper focuses on the wind profile model, a companion paper articulates the wave spectrum model. For wind profiles under typhoon conditions, the power-law and log-law models have been found applicable under the condition that the Hellmann exponent α or the friction velocity u* are modified to vary with the wind strength. For wind profiles under non-typhoon conditions, the log-law model is revised to take into consideration the influence of the atmospheric stability. [ABSTRACT FROM AUTHOR]
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- 2017
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7. Magma emplacement: an important trigger leading to slope failures in deep-water areas of northern continental margin of South China Sea.
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Ma, Y., Li, S. Z., Lin, J. Q., Liang, Q. Y., Shi, Y. H., and Kong, L.
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MAGMAS , *SLOPES (Physical geography) , *CONTINENTAL margins , *GEOLOGY - Abstract
Submarine slope failures are considered as a serious geo-hazard because they can rupture undersea pipelines, and seafloor engineering facilities can be subverted by destroying the seabed stability. Submarine slope failures are widely developed in deep-water areas of the northern continental margin of the South China Sea, yet the mechanisms involved in their generation remain poorly known. Observations have proposed that slope instability can be due either to decomposition of gas hydrate or to magma emplacement. Here, we present new high-resolution 2D seismic data from the deep-water areas of the northern continental margin of the South China Sea to reveal an extensive and intimate relationship between magma emplacement and slope failures. This paper shows four landslides on the Dongsha, Shenhu, Xisha and Qiongdongnan slopes that occurred at different locations of the northern continental slope of the South China Sea. There are seismic evidences that magmatic rocks commonly developed and migrated upwards to the overlying layers and they caused these layers to uplift as a dome and possibly decreased their strength and predisposition to failure. The data reveal in detail how magma emplacement influenced slope stability and the seismic reflection features of this type of submarine landslides. The findings illustrate the importance of magma emplacement resulting in slope instability. This paper proposes that magma emplacement is a basic and critical trigger leading to slope failures in the deep-water areas of the northern continental margin of the South China Sea and establishes genetic models for this important trigger. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
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- 2016
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8. Classification of Coral Reefs in the South China Sea by Combining Airborne LiDAR Bathymetry Bottom Waveforms and Bathymetric Features.
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Su, Dianpeng, Yang, Fanlin, Ma, Yue, Zhang, Kai, Huang, Jue, and Wang, Mingwei
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CORAL reefs & islands , *LIDAR , *BATHYMETRY , *GEOGRAPHIC information systems , *REMOTE sensing - Abstract
Geographic information describing coral reefs plays an important role in constructing electronic chart systems and protecting the ecological environment of the ocean. To derive geographic information of coral reefs more effectively, this paper proposes a methodology to detect coral reefs by combining airborne LiDAR bathymetry (ALB) bottom waveform and bathymetric feature data. A feature vector was established by deriving bottom waveform variables (the peak amplitude, pulsewidth, area, skewness, kurtosis, and backscatter cross section) and bathymetric variables (the depth standard deviation, slope, bathymetric position index, Gaussian curvature, mean curvature, and roughness). Using a support vector machine classifier, coral reefs were detected by distinguishing two classes (coral reefs and others) on the seafloor. To evaluate the classification performance of coral reefs, the developed method was applied to Yuanzhi Island, South China Sea surveys, and verified by field data (aerial digital camera images and underwater video images). The results showed that the classification overall accuracy of coral reefs can be greatly improved from 80.59%/90.31% when ALB bottom waveform or bathymetric variables features were used separately to 93.57% when using a combination of ALB bottom waveform and bathymetric features. In addition, the kappa coefficient can also be greatly improved from approximately 0.61/0.80 to 0.87. And the new proposed method performs better compared to the current classification method using ALB data to detect coral reefs with an overall accuracy of 90.92% and Kappa of 0.81. This highlights the potential of ALB data, combining waveform data and bathymetric data, for precisely detecting coral reefs in shallow water areas. [ABSTRACT FROM AUTHOR]
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- 2019
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9. Evaluation of the Quasi-Biweekly Oscillation over the South China Sea in Early and Late Summer in CAM5.
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Wang, Xu and Zhang, Guang J.
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MADDEN-Julian oscillation , *GENERAL circulation model , *VORTEX motion , *MERIDIONAL winds - Abstract
Low-frequency intraseasonal oscillations in the tropical atmosphere in general circulation models (GCMs) were studied extensively in many previous studies. However, the simulation of the quasi-biweekly oscillation (QBWO), which is an important component of the intraseasonal oscillations, in GCMs has not received much attention. This paper evaluates the QBWO features over the South China Sea in early [May–June (MJ)] and late [August–September (AS)] summer in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model, version 5.3 (CAM5), using observations and reanalysis data. Results show that the major features of the spatial distribution of the QBWO in both MJ and AS are simulated reasonably well by the model, although the amplitude of the variation is overestimated. CAM5 captures the local oscillation in MJ and the westward propagation in AS of the QBWO. Although there are important biases in geographical location and intensity in MJ, the model represents the QBWO horizontal and vertical structure qualitatively well in AS. The diagnosis of the eddy vorticity budget is conducted to better understand the QBWO activities in the model. Both horizontal advection of relative vorticity and that of planetary vorticity (Coriolis parameter) are important for the local evolution of the QBWO in MJ in observations as well as model simulation, whereas advection of planetary vorticity contributes to the westward propagation of QBWO vorticity anomalies in AS. Since the Coriolis parameter f only changes with latitude, this suggests that the correct simulation of anomalous meridional wind is a key factor in the realistic simulation of the QBWO in the model. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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10. Mineralogical and geochemical characteristics of K‐bentonites from the Late Ordovician to the Early Silurian in South China and their geological significance.
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Ge, Xiangying, Mou, Chuanlong, Wang, Chengshan, Men, Xin, Chen, Chao, Hou, Qian, and Somerville, I.D.
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MINERALOGY , *GEOCHEMISTRY , *ORDOVICIAN Period , *BLACK shales , *BENTONITE - Abstract
There are numerous K‐bentonites interlayered with black shales from the Late Ordovician‐Early Silurian that are widely distributed in South China. In this paper, we carried out mineralogical and geochemical investigations on K‐bentonite samples collected from 6 sections in South China. The petrological features of thin sections, X‐ray diffraction data, and major element results show that in addition to clay minerals, which are dominated by illite/smectite mixed layer and illite, the K‐bentonites also contain quartz, microcline, albite, pyrite, and zircon. Zircon U–Pb dating for two K‐bentonite beds (WXP‐BT2 and LBP‐BT1) by the LA‐ICP‐MS method yielded two weighted mean 206Pb/238U ages of 443.5 ± 1.9 and 440.4 ± 5.6 Ma, respectively. The concentrations of rare earth elements (REEs) range from 141.28 to 854.44 ppm, chondrite‐normalized REE patterns display a negative Eu anomaly and an enhanced enrichment in light REE. Samples plot in the fields of trachyte, trachyandesite, rhyodacite (dacite), and andesite in a plot of Nb/Y against Zr/TiO2 suggest that the K‐bentonites are most probably derived from felsic magmas with subalkaline to alkaline affinities. The discrimination diagrams (Y‐Nb, Y + Ta‐Rb, Y + Nb‐Rb) show that the tectonic setting of the source volcanoes ranges from a volcanic arc to within‐plate setting. The widely distributed bentonites suggest intensified volcanic ash eruptions in the early Late Ordovician, which released huge amounts of volcanic ash. The SO2 emission and the weathering of the volcanic ashes probably resulted in global climate cooling and indirectly caused the Hirnantian glaciation and the mass extinction at the end of the Ordovician Period. [ABSTRACT FROM AUTHOR]
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- 2019
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11. Late Mesozoic transition from Andean‐type to Western Pacific‐type of the East China continental margin—Is the East China Sea basement an allochthonous terrain?
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Ding, Weiwei, Li, Jiabiao, Wu, Zhaocai, Li, Sanzhong, and Lin, Xiubin
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PLATE tectonics , *CONTINENTAL margins , *OCEANOGRAPHY , *STRUCTURAL geology - Abstract
Geophysical features and crustal structure of the East China Sea basement were revealed based on geophysical inversion analysis with recent gravity and magnetic data. Our results show great differences between the East China Sea continental shelf basins and the Zhemin Volcanic Belt in the coastal South China Block with respect to geophysical features and crustal structures. These areas are separated by distinct geophysical and crustal changes, approximately along a line 100 km from the coastline of China. We hypothesize that the East China Sea basement is a buoyant allochthon in the Palaeo‐Pacific Plate, and that the East China margin was an Andean‐type active continental margin until the collision of the East China Sea basement with the South China Block in the Late Cretaceous, which jammed the Late Cretaceous Trench, terminating the subduction and the related granitoid magmatism. The East China continental margin was dominated by dextral transtension with limited magmatism due to the NNW‐trend motion of the Palaeo‐Pacific Plate with a reduced convergence rate until the Middle Eocene. The renewed westward subduction of the present‐day Pacific Plate replaced the East China Andean‐type continental margin with a Western Pacific‐type one. The detailed reconstructed tectonic model for the East China Sea since the Mesozoic is presented in this paper. [ABSTRACT FROM AUTHOR]
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- 2018
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12. Impact of the South China Sea Summer Monsoon on the Indian Ocean Dipole.
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Zhang, Yazhou, Li, Jianping, Xue, Jiaqing, Feng, Juan, Wang, Qiuyun, Xu, Yidan, Wang, Yuehong, and Zheng, Fei
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MONSOONS , *WINDS , *METEOROLOGICAL precipitation , *RAINFALL , *MARINE ecology - Abstract
This paper investigates the impact of the South China Sea summer monsoon (SCSSM) on the Indian Ocean dipole (IOD). The results show that the SCSSM has a significant positive relationship with the IOD over the boreal summer [June–August (JJA)] and fall [September–November (SON)]. When the SCSSM is strong, the enhanced southwesterly winds that bring more water vapor to the western North Pacific (WNP) lead to surplus precipitation in the WNP, inducing anomalous ascending there. Consequently, the anomalous descending branch of the SCSSM Hadley circulation (SCSSMHC) develops over the Maritime Continent (MC), favoring deficit precipitation in situ. The precipitation dipole over the WNP and MC as well as the enhanced SCSSMHC leads to intensification of the southeasterly anomalies off Sumatra and Java, which then contributes to the negative sea surface temperature (SST) anomalies through the positive wind–evaporation–SST and wind–thermocline–SST (Bjerknes) feedbacks. Consequently, a positive IOD develops because of the increased zonal gradient of the tropical Indian Ocean SST anomalies and vice versa. The SCSSM has a peak correlation with the IOD when the former leads the latter by three months. This implies that a positive IOD can persist from JJA to SON and reach its mature phase within the frame of the positive Bjerknes feedback in SON. In addition, the local and remote SST anomalies in the tropical Indian and Pacific Oceans have a slight influence on the relationship between the SCSSM and precipitation dipole over the WNP and MC. [ABSTRACT FROM AUTHOR]
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- 2018
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13. Macro-meso effects of gradation and particle morphology on the compressibility characteristics of calcareous sand.
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Shen, Yang, Li, An, Ge, Huayang, Zhu, Yinghao, and Liu, Hanlong
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SAND - Abstract
In order to fully develop the South China Sea, a large number of reclamation projects using calcareous sand have been carried out in this area recently. A deep understanding of the physical and mechanical properties of calcareous sand is of critical importance. Therefore, the calcareous sand near a certain reef of the South China Sea is used in this study to investigate the effect of three-dimensional (3-D) particle morphology and gradation on the compressibility characteristics of calcareous sand. This paper proposes a 3-D mesoscope observation method to obtain the average 3-D angularity parameter Sd and 3-D aspect ratio Td of calcareous sand with different particle sizes. It is found that the morphology of coarse particles (diameter: 5 ~ 1 mm) is significantly multi-angular, while the morphologies of middle particles (1 ~ 0.25 mm) are mostly dendritic and schistic. Compared to the 3-D Sd of quartz sand, the calcareous sand’s particle morphology is much more irregular and multi-angular, which makes it easy for the calcareous sand to form large pores and, thus, be more compressible. In order to systematically study the effect of gradation on the calcareous sand’s compressibility characteristics, a number of compression tests on calcareous sand with different gradations are taken. The influential mechanism is then discussed by analyzing the test results from a mesoscopic viewpoint. It is found that changing the coarse fraction content is the most efficient way to reduce the compressibility of the calcareous sand. That is because of the coarse fraction’s high angularity, which makes the skeleton-bearing capacity of the calcareous sand sensitive to the change of coarse fraction content. An empirical formula is proposed to evaluate the compressibility of the calcareous sand with different coarse fraction contents. [ABSTRACT FROM AUTHOR]
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- 2018
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14. Research on bilateral reverse migration of one-group seabed sand waves in a small shallow shelf sea.
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Jiang, Wenbin and Lin, Mian
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OCEAN bottom , *SAND waves , *MATHEMATICAL models , *WAVE-current interaction , *FLUCTUATIONS (Physics) , *BED load - Abstract
Bilateral reverse migration of one-group seabed sand waves is found recently in many small sea areas and is a potential threat to the safety of many near seabed engineering structures, such as pipelines and cables. The mechanism cannot clearly be explained by existing theories. This paper focuses on the bilateral reverse migration of one-group seabed sand waves around a sand ridge in a small shallow shelf sea of the South China Seas, and presents a developed numerical model consisting of three-dimensional wave–current coupling module and sand transport module to simulate this complex phenomenon and perform relative analysis on the characteristics of the current and bilateral reverse migration formation mechanism. Taking the ocean environment characteristics of the surrounding sea area into account and with sufficient grid resolution, this model successfully depicts the process of sand wave bilateral reverse migration. Bottom friction velocity is taken as the inspecting physical quantity and divided into tidal, residual and short-term fluctuation components through harmonic analysis; with a method based on bedload transport calculation, the contributions of the above three parts are determined. It is found that long-term sand wave migration trend is primarily controlled by both tidal constituents and residual velocity. Under nonlinear pure tidal impact, the sand waves migrate southwards; the residual current is northwards and will cancel the tidal impact. When the magnitude of the residual velocity is large enough, i.e., in the western part of the sand wave area, sand waves migrate northwards; when the residual velocity is small, i.e., in the eastern part, sand waves migrate southwards and the bilateral reverse migration pattern is formed. The residual velocity distribution relates closely to the surrounding topography. This paper discloses one kind of mechanisms for bilateral reverse migration of one-group seabed sand waves, and the model and analysis framework can also be extended and applied to other similar situations to prompt deeper and more comprehensive understanding about sand wave migration. [ABSTRACT FROM AUTHOR]
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- 2016
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15. Field Measurements of Rogue Water Waves.
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Christou, Marios and Ewans, Kevin
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ROGUE waves , *OFFSHORE structures , *OCEAN waves , *DISPERSION (Chemistry) , *OCEAN circulation , *OCEANOGRAPHY - Abstract
This paper concerns the collation, quality control, and analysis of single-point field measurements from fixed sensors mounted on offshore platforms. In total, the quality-controlled database contains 122 million individual waves, of which 3649 are rogue waves. Geographically, the majority of the field measurements were recorded in the North Sea, with supplementary data from the Gulf of Mexico, the South China Sea, and the North West shelf of Australia. The significant wave height ranged from 0.12 to 15.4 m, the peak period ranged from 1 to 24.7 s, the maximum crest height was 18.5 m, and the maximum recorded wave height was 25.5 m. This paper will describe the offshore installations, instrumentation, and the strict quality control procedure employed to ensure a reliable dataset. An examination of sea state parameters, environmental conditions, and local characteristics is performed to gain an insight into the behavior of rogue waves. Evidence is provided to demonstrate that rogue waves are not governed by sea state parameters. Rather, the results are consistent with rogue waves being merely extraordinary and rare events of the normal population caused by dispersive focusing. [ABSTRACT FROM AUTHOR]
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- 2014
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16. Structural inversion in the northern South China Sea continental margin and its tectonic implications.
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Chin-Da Huang, Tung-Yi Lee, Ching-Hua Lo, Sun-Lin Chung, Jong-Chang Wu, Ching-Lung Tien, Meng-Wan Yeh, Shiu-Chi Chen, Yu-Lu Chan, and Ching-Yi Hu
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INVERSION (Geophysics) , *STRUCTURAL geology , *SEISMOLOGY , *CONTINENTAL margins - Abstract
The northern South China Sea (SCS) continental margin was proposed to be an active margin during the Mesozoic. However, only a few papers discussed the Mesozoic structural evolution in this region. Here, we provide information based on the seismic profile interpretations with age control from biostratigraphic studies and detrital zircon U-Pb dates of well MZ-1-1 in the western Dongsha-Penghu Uplift of the northern SCS continental margin. The industrial seismic profiles reveal evidence for structural inversion as represented by folds and high-angle reverse faults, formed by reactivation of pre-existing normal faults. The inversion event likely started after the Early Cretaceous, and developed in Late Cretaceous, but ceased before the Cenozoic. The areal extent of the structural inversion was restricted in the western Dongsha-Penghu Uplift and was approximately 100 km in width. Based on the paleogeographic reconstruction of SCS, the structural inversion was likely formed by a collision between the seamount (volcanic islands) swarm of the current North Palawan block (mainly the Calamian Islands) and the northern SCS continental margin around Late Cretaceous. [ABSTRACT FROM AUTHOR]
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- 2017
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17. YELLOWFIN TUNA (THUNNUSALBACARES) FISHING GROUND FORECASTING MODEL BASED ON BAYES CLASSIFIER IN THE SOUTH CHINA SEA.
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ZHOU Wei-feng, LI An-zhou, JI Shi-jian, and QIU Yong-song
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YELLOWFIN tuna , *FISHING , *BAYES' theorem , *OCEAN temperature - Abstract
Using the yellowfin tuna (Thunnusalbacares,YFT)longline fishing catch data in the open South China Sea (SCS) provided by WCPFC, the optimum interpolation sea surface temperature (OISST) from CPC/NOAA and multi-satellites altimetric monthly averaged product sea surface height (SSH) released by CNES, eight alternative options based on Bayes classifier were made in this paper according to different strategies on the choice of environment factors and the levels of fishing zones to classify the YFT fishing ground in the open SCS. The classification results were compared with the actual ones for validation and analyzed to know how different plans impact on classification results and precision. The results of validation showed that the precision of the eight options were 71.4%, 75%, 70.8%, 74.4%, 66.7%, 68.5%, 57.7% and 63.7% in sequence, the first to sixth among them above 65% would meet the practical application needs basically. The alternatives which use SST and SSH simultaneously as the environmental factors have higher precision than which only use single SST environmental factor, and the consideration of adding SSH can improve the model precision to a certain extent. The options which use CPUE's mean ± standard deviation as threshold have higher precision than which use CPUE's 33.3%-quantile and 66.7%-quantile as the threshold. [ABSTRACT FROM AUTHOR]
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- 2017
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18. A Long Gravity-Piston Corer Developed for Seafloor Gas Hydrate Coring Utilizing an In Situ Pressure-Retained Method.
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Jia-Wang Chen, Wei Fan, Brian Bingham, Ying Chen, Lin-Yi Gu, and Shi-Lun Li
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GAS hydrates , *SEDIMENTS , *SUBMARINE topography , *SUBMARINE trenches - Abstract
A corer, which can obtain long in situ pressure-retained sediments of up to 30 m core containing gas hydrates, has been applied in the South China Sea (SCS) dozens of times. The corer presented in this paper is a convenient, efficient and economical long in situ pressure-retained coring and research tool for submarine sediments, that can applied to completely cope with all sediments close to the seafloor ranging from shallow waters to the deep sea depths of 6000 m. This article mainly presents the overall structure, working principles, key pressure-retained components, coring mechanism, sea trials and outlook of the corer. The analyses found that the coring ability was affected by formation characteristics, the outer diameter of the core barrels and inner diameter of the core liners, the shapes of the cutter and the dead weight of the corer. This study can provide the practical basis for the structural optimization of this type of corer and designs for corers with greater penetrability. Sea trials showed that the developed corer presented in this paper can support the in situ pressure of the seafloor sediment core, which is an improvement over the conventional piston corer. [ABSTRACT FROM AUTHOR]
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- 2013
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19. Progress of regional oceanography study associated with western boundary current in the South China Sea.
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Wang, DongXiao, Liu, QinYan, Xie, Qiang, He, ZhiGang, Zhuang, Wei, Shu, YeQiang, Xiao, XianJun, Hong, Bo, Wu, XiangYu, and Sui, DanDan
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OCEANOGRAPHY , *OCEAN currents , *EDDY flux , *OCEAN-atmosphere interaction , *COUNTERCURRENT processes - Abstract
Recent progress of physical oceanography in the South China Sea (SCS) associated with the western boundary current (WBC) and eddies is reviewed in this paper. It includes Argo observations of the WBC, eddy detection in the WBC based on satellite images, cross-continental shelf exchange in the WBC, eddy-current interaction, interannual variability of the WBC, air-sea interaction, the SCS throughflow (SCSTF), among others. The WBC in the SCS is strong, and its structure, variability and dynamic processes on seasonal and interannual time scales are yet to be fully understood. In this paper, we summarize progresses on the variability of the WBC, eddy-current interaction, air-sea interaction, and the SCSTF achieved in the past few years. Firstly, using the drifting buoy observations, we point out that the WBC becomes stronger and narrower after it reaches the central Vietnam coast. The possible mechanisms influencing the ocean circulation in the northern SCS are discussed, and the dynamic mechanisms that induce the countercurrent in the region of northern branch of WBC in winter are also studied quantitatively using momentum balance. The geostropic component of the WBC was diagnosed using the ship observation along 18°N, and we found that the WBC changed significantly on interannual time scale. Secondly, using the ship observations, two anti-cyclonic eddies in the winter of 2003/2004 in the northern SCS, and three anti-cyclonic eddies in the summer of 2007 along 18°N were studied. The results show that the two anti-cyclonic eddies can propagate southwestward along the continental shelf at the speed of first Rossby wave (∼0.1 m s) in winter, and the interaction between the three anti-cyclonic eddies in summer and the WBC in the SCS is preliminarily revealed. Eddies on the continental shelf of northern SCS propagated southeastward with a maximum speed of 0.09 m s, and those to the east of Vietnam coast had the largest kinetic energy, both of which imply strong interaction between eddy activity and WBC in the SCS. Thirdly, strong intraseasonal variability (ISV) of sea surface temperature (SST) near the WBC regions was found, and the ISV signal of SST in winter weakens the ISV signal of latent heat flux by 20%. Fourthly, the long-term change of SCSTF volume transport and its connection with the ocean circulation in the Pacific were discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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20. Objective determination of the onset and withdrawal of the South China Sea summer monsoon.
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Luo, Ming and Lin, Lijie
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MONSOONS , *WHIRLWINDS , *ZONAL winds , *OSCILLATIONS - Abstract
Determining the timing (i.e. onset and withdrawal) of monsoon season precisely and objectively is an important yet difficult task. Conventional methods mainly define the monsoon timing as the date when the selected atmospheric variables (e.g. rainfall and wind) exceed an arbitrary threshold. These methods present little explicit justification and are subjective and sensitive to the fluctuation of the selected series. In this study, we propose an objective method to determine the onset and withdrawal of the South China Sea summer monsoon ( SCSSM) using the cumulative low-level zonal wind. Our proposed approach provides an easy, objective, and applicable method that is recommended for the detection of the timing of monsoon season. On the basis of the proposed definition, the SCSSM onset and withdrawal are determined, and their accompanying processes are also examined in this paper. Both onset and withdrawal of SCSSM exhibit strong variability, and the El Niño-Southern Oscillation plays an important role. Via the modification of the western North Pacific subtropical high, a preceding El Niño (La Niña) event can delay (advance) the monsoon onset and advance (delay) the monsoon withdrawal. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
21. Building Cooperation for Managing the South China Sea Without Strategic Trust.
- Author
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Bateman, Sam
- Subjects
- *
MARITIME shipping , *STRATEGIC planning - Abstract
The ruling from the arbitral tribunal dealing with the case between China and the Philippines in the South China Sea provides opportunities for fresh approaches to building cooperation for managing the sea and activities within it. This cooperation is both a necessity and an obligation of the countries bordering the sea. However, obstacles remain, particularly the lack of trust between the various stakeholders in the sea and the way in which important areas for cooperation, such as fisheries management, environmental protection and marine scientific research, have been politicised to the extent that even cooperation in these areas cannot proceed without greater strategic trust. The objective of this paper is to put forward a set of policy implications from the ruling that might overcome these obstacles and allow the necessary cooperation to proceed despite the lack of strategic trust. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
22. Application of the PJ and NPS evaporation duct models over the South China Sea (SCS) in winter.
- Author
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Yang, Shaobo, Li, Xingfei, Wu, Chao, He, Xin, and Zhong, Ying
- Subjects
- *
NONPOINT source pollution , *EVAPORATION (Meteorology) , *HYDROLOGICAL instruments ,NAVAL Postgraduate School (Monterey, Calif.) - Abstract
The detection of duct height has a significant effect on marine radar or wireless apparatus applications. The paper presents two models to verify the adaptation of evaporation duct models in the SCS in winter. A meteorological gradient instrument used to measure evaporation ducts was fabricated using hydrological and meteorological sensors at different heights. An experiment on the adaptive characteristics of evaporation duct models was carried out over the SCS. The heights of the evaporation ducts were measured by means of log-linear fit, Paulus-Jeske (PJ) and Naval Postgraduate School (NPS) models. The results showed that NPS model offered significant advantages in stability compared with the PJ model. According the collected data computed by the NPS model, the mean deviation (MD) was -1.7 m, and the Standard Deviation (STD) of the MD was 0.8 m compared with the true value. The NPS model may be more suitable for estimating the evaporation duct height in the SCS in winter due to its simpler system characteristics compared with meteorological gradient instruments. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
23. Can private management compensate the ineffective marine reserves in China?
- Author
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Huang, Hui, Wen, Colin, Li, Xiubao, Tao, Yuan, Lian, Jainshen, Yang, Jianhui, and Cherh, Kah-Leng
- Subjects
- *
MARINE parks & reserves , *PRIVATE sector , *MARINE debris , *CORAL reef management - Abstract
Marine reserves (MRs) have emerged as a preferred method to protect coral reefs from overfishing and human disturbance. However, due to ineffective enforcement by governments, many MRs have been reduced to mere 'paper parks' which fail to achieve conservation goals. This is especially true in countries such as China where compliance is low and resources dedicated to enforcement may be scarce. Privately managed marine reserves (PMMRs) may be effective in areas where government enforcement is lacking. To determine if PMMRs are a viable alternative strategy to protect coral reefs, we surveyed and compared fish assemblages and coral coverage in national MRs in Sanya, China to areas of reef privately leased to and managed by dive operators and hospitality industries. We found higher fish abundances and fish sizes in PMMR sites than in MR sites. However, while PMMRs are protected from fishing, other human impacts such as marine debris and illegal coral collection were evident in most tourist sites. Despite protection, long-term monitoring data of PMMRs revealed that in recent years, fish abundances have slightly recovered but species richness has not, indicating the need for a more comprehensive coral reef management plan. We strongly recommend coupling PMMRs with expertise supported regulations as an alternative coral reef management strategy in China. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
24. Reflections on the South China Sea arbitration rulings.
- Author
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Keith, Kenneth
- Subjects
- *
INTERNATIONAL arbitration -- Cases , *INTERNATIONAL economic relations , *CONFLICT of laws -- Jurisdiction , *DIPLOMATIC negotiations in international disputes , *INTERNATIONAL relations - Abstract
The author comments on the decision of the internal arbitral tribunal in the case brought against China by the Philippines. He cites several arbitration cases including that of Argentina and Uruguay relating to a pulp and paper mill, the Rainbow Warrior case between France and New Zealand, and the Russian Federation and China's dispute settlement. Other topics discussed include China's reasons for not honoring the tribunal's claim for jurisdiction and opposing interests in the South China Sea.
- Published
- 2017
25. The phase equilibria of multicomponent gas hydrate in methanol/ethylene glycol solution based formation water.
- Author
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Xu, Shurui, Fan, Shuanshi, Yao, Haiyuan, Wang, Yanhong, Lang, Xuemei, Lv, Pingping, and Fang, Songtian
- Subjects
- *
PHASE equilibrium , *MULTIPHASE flow , *GAS hydrates , *METHANOL , *ETHYLENE glycol , *SOLUTION (Chemistry) - Abstract
In this paper, the three-phase coexistence points are generated for multicomponent gas hydrate in methanol (MeOH) solution for (0.05, 0.10, 0.15, and 0.35) mass fraction and ethylene glycol (EG) solution for (0.05, 0.10, 0.15, 0.35, 0.40 and 0.55) mass fraction. The phase equilibrium curves of different system were obtained by an isochoric pressure-search method on high pressure apparatus. The phase equilibrium regions of multicomponent gas hydrate were measured using the same composition of natural gas distributed in the South China Sea. And the different concentration solutions were prepared based formation water. The experimental data were measured in a wide range temperature from 267.74 to 298.53 K and a wide range pressure from 4.22 MPa to 34.72 MPa. The results showed that the hydrate phase equilibrium curves shifted to the inhibition region in accordance with the increased inhibitor concentration. In addition, the equilibrium temperature would decrease about 2.7 K when the concentration of MeOH increased 0.05 mass fraction. Besides, the suppression temperature was 1.25 K with the 0.05 mass fraction increase of EG concentration in the range of 0.05 mass fraction to 0.15 mass fraction. While in high EG concentration region, the suppression temperature was 3.3 K with the same increase of EG concentration (0.05 mass fraction). [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
26. Fisheries in the South China Sea: A Centrifugal or Centripetal Force?
- Author
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Franckx, Erik
- Subjects
- *
FISHERIES , *AQUATIC resources , *CENTRIFUGAL force , *CENTRIPETAL force - Abstract
The present paper intends to have a look at fisheries in the South China Sea in order to find out whether this particular issue is a problem solver or rather a problem creator in this region characterized by tense inter-State relationships at present. In this part of the world's ocean, dominated by maritime features such as the Paracels and the Spratleys, i.e. shallow areas, sometimes drying only at low tide, and sometimes at high tide as well, fish is a plentiful resource relied upon by many fishermen of the surrounding countries as a source of income. If we take Europe as an example, fisheries seem to have the dual capability to either trigger disputes between States, resulting sometimes in outright fish wars, or to provide a means of furthering integration between States, such as has been accomplished by the European Common Fisheries Policy. In the South China Sea a similar duality can be witnessed. At times, fishermen have dramatically influenced the relations between certain States to the point of suddenly straining diplomatic relations totally disproportionately to the event which had triggered a particular incident. But fisheries are also used as a vehicle for trying to further co-operation on both bilateral and regional levels. Indeed, very often fisheries are seen as a more “neutral” area able to stimulate co-operation more easily than, for instance, co-operation in the military field or on sovereignty-related issues. This paper will conclude by determining whether Article 123 of the 1982 United Nations Convention on the Law of the Sea adds any legal obligation to the riparian States of a semi-enclosed sea in this respect. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
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27. Long-Term Variability of Extreme Significant Wave Height in the South China Sea.
- Author
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Osinowo, Adekunle, Lin, Xiaopei, Zhao, Dongliang, and Wang, Zhifeng
- Subjects
- *
ALTIMETERS , *WIND waves , *SPATIOTEMPORAL processes , *TREND analysis , *METEOROLOGICAL research - Abstract
This paper describes long-term spatiotemporal trends in extreme significant wave height (SWH) in the South China Sea (SCS) based on 30-year wave hindcast. High-resolution reanalysis wind field data sets are employed to drive a spectral wave model WAVEWATCH III™ (WW3). The wave hindcast information is validated using altimeter wave information (Topex/Poseidon). The model performance is satisfactory. Subsequently, the trends in yearly/seasonal/monthly mean extreme SWH are analyzed. Results showed that trends greater than 0.05 m yr−1 are distributed over a large part of the central SCS. During winter, strong positive trends (0.07–0.08 m yr−1) are found in the extreme northeast SCS. Significant trends greater than 0.01 m yr−1 are distributed over most parts of the central SCS in spring. In summer, significant increasing trends (0.01–0.05 m yr−1) are distributed over most regions below latitude 16°N. During autumn, strong positive trends between 0.02 and 0.08 m yr−1 are found in small regions above latitude 12°N. Increasing positive trends are found to be generally significant in the central SCS in December, February, March, and July. Furthermore, temporal trend analysis showed that the extreme SWH exhibits a significant increasing trend of 0.011 m yr−1. The extreme SWH exhibits the strongest increasing trend of 0.03 m yr−1 in winter and showed a decreasing trend of −0.0098 m yr−1 in autumn. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
28. Gravity anomaly in the southern South China Sea: a connection of Moho depth to the nature of the sedimentary basins' crust.
- Author
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Lei, J. P., Jiang, S. H., Li, S. Z., Gao, S., Zhang, H. X., Wang, G., and Zhao, F. Y.
- Subjects
- *
GRAVITY anomalies , *MOHOROVICIC discontinuity , *SEDIMENTARY basins , *GEOLOGY - Abstract
To study the distribution characteristics of the Moho interface and the relationship between the Moho depth and the main sedimentary basins in the southern South China Sea and its adjacent areas, this paper adopts gravity anomaly data and multi-scale decomposition of two-dimension discrete wavelet transform to analyse the gravity field and the characteristics of the multi-order decomposition in the study area. Through the method of Parker-Oldenburg Iterative Inversion, the Moho depth of the study area has been obtained based on four-order approximation of Bouguer anomaly and constrained by the data of the CRUST1.0 model. By analysis and comparison, the optimum inversion parameters and the final inversion results of the Parker-Oldenburg Iterative Inversion have been explored. The distribution of the Moho depth in the study area takes on a double 'V'-type characteristic. In addition, the Moho morphology of the three main kinds of basins in the study area has also been concluded. The crustal thickness of the sedimentary basin indicates, in the case of the nature of the basins' crust, that the transition from north to south is from continental crust to transitional crust. These results provide the basis for further study of the gravity field, the deep geological structure in the southern South China Sea and the prediction of oil and gas prospects. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
29. Structures around the Tinjar-West Baram Line in northern Kalimantan and seafloor spreading in the proto-South China Sea.
- Author
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Zheng, Q. L., Li, S. Z., Suo, Y. H., Li, X. Y., Guo, L. L., Wang, P. C., Zhang, Y., Zang, Y. B., Jiang, S. H., and Somerville, I. D.
- Subjects
- *
SPREADING centers (Geology) , *LITHOSPHERE , *PLATE tectonics - Abstract
The Tinjar-West Baram Line is a NW-trending trans-lithospheric fault in northern Kalimantan; its northwestern extension into the South China Sea (SCS) is the West Baram Line. In this paper, we propose that the geodynamic processes of the proto-South China Sea (PSCS) played a key role in the formation and evolution of the Tinjar-West Baram Line, based on previous studies of the strata, crustal thicknesses, gravity anomalies and other characteristics of the blocks adjacent to the Tinjar-West Baram Line and the palaeomagnetic-based plate reconstructions of the PSCS. The Tinjar-West Baram Line has a close link to the subduction of the PSCS. Structural restoration reveals that (1) before 35 Ma, the Tinjar-West Baram Line was a NE-trending transform fault, which is consistent with the NE-trending strike-slip faults widely distributed in the East Asian Continental Margin, in the PSCS. (2) From the perspective of tectonic evolution, the extinction of the PSCS and the spreading of the SCS drove the Luconia Block in the northern SCS to accrete to the western side of the Tinjar-West Baram Line. This process resulted in a contrast of crustal rocks adjacent to the Tinjar-West Baram Line; to the east of this line, the Nansha Trough is oceanic crust, whereas to the west of this line the Luconia Block has an affinity with continental crust. The velocity and thickness of the crust show great differences on either side of the Tinjar-West Baram Line. (3) The kinematic analysis of the Tinjar-West Baram Line reveals that the collisional orogeny between the Luconia and Kalimantan blocks happened at 45-37 Ma on the west of the Tinjar-West Baram Line; on its eastern side, the Nansha Trough was subducting south towards Kalimantan Island. During the interval 35-10 Ma, the kinematics of the Tinjar-West Baram Line shows a feature of dextral strike-slip faulting. (4) The earlier published palaeomagnetic data show that the Kalimantan Block experienced a counterclockwise rotation of about 50° during the period from 25 to 10 Ma. In addition, the exert counterclockwise rotation of about 20° of the Tinjar-West Baram Line happened due to the resistance of the Luconia Block. Therefore, the Tinjar-West Baram Line changed from an early NE-trending to late NW-trending structure which results in its present day tectonic framework. Thus, we suggest that the Tinjar-West Baram Line was originally a NE-trending transform fault of the PSCS extending to the continental crust. Subsequently, the Tinjar-West Baram Line became the western border of the PSCS, accompanying the collisional orogeny between the Luconia and Kalimantan blocks. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
30. Origin of transform faults in back-arc basins: examples from Western Pacific marginal seas.
- Author
-
Zhang, Y., Li, S. Z., Suo, Y. H., Guo, L. L., Yu, S., Zhao, S. J., Somerville, I. D., Guo, R. H., Zang, Y. B., Zheng, Q. L., and Mu, D. L.
- Subjects
- *
TRANSFORM faults , *BACK-arc basins , *ATMOSPHERIC troughs - Abstract
Transform faults in back-arc basins are the key to revealing the evolution of marginal seas. Four marginal basins in the Western Pacific, i.e. the South China Sea (SCS), Okinawa Trough (OT), West Philippine Basin (WPB) and Shikoku-Parece Vela Basin (SPVB), were studied to redefine the strikes and spatial distribution of transform faults or fracture zones. Based on high-resolution tectonomorphology, gravity and magnetic anomalies, pattern of magnetic lineations, seismic profiles, geometry of basins and palaeomagnetic data, together with analyses of regional geological setting, plate reconstruction and geodynamic analysis, this paper suggests that all the transform faults in the four marginal basins are in general NNE-trending. Moreover, by comparing with the contemporary structural framework of the East Asian Continental Margin, we propose new models concerning marginal seas spreading and have revised the previous Cenozoic plate reconstruction models related to the East Asian Continental Margin and the Western Pacific marginal seas. There are three possible origins of these NNE-trending transform faults. 1. Inheriting the orientation of the strike-slip faults at the rifting continental margin (e.g. the SCS and OT). The real strike of transform faults should not be NW but NNE. The large-scale NNE-trending dextral strike-slip faults distributed in the continental shelf of the SCS control a series of pull-apart basins of the SCS. Due to a higher degree of pull-apart, oceanic crust began to open. Then they evolved into the NNE-trending transform faults in the SCS and could also be regarded as a natural extension of the NNE-trending strike-slip faults in the South China Block (SCB). The geodynamic mechanism of the OT is similar to that of the SCS. Consequently, transform faults of the OT should also be NNE-trending, which is not perpendicular to the spreading axis but instead displays oblique spreading. 2. Izu-Bonin-Mariana (IBM) Trench retreat to the NNE and NE. Subduction rollback to the NE and NNE produced the NE- and NNE-striking horizontal tensile stress, resulting in the rifting of the Kyushu-Palau Ridge (KPR), controlling the spreading of the SPVB and forming the NE- and NNE-trending transform faults. This also involves oblique spreading. 3. The later overall rotation of the Philippine Sea Plate (PSP). Since 25 Ma, the WPB has rotated clockwise about 40°. Therefore the NW- and NNW-trending transform faults that formed at the later spreading stage have rotated to be the near-N-S- or NNE-striking faults. These transform faults are almost perpendicular to the spreading axis. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
31. Similarity and differentiation between the East China Sea Shelf Basin and Cenozoic basins in the northeast South China Sea.
- Author
-
Zang, Y. B., Li, S. Z., Guo, L. L., Suo, Y. H., Somerville, I. D., Zhao, S. J., Hui, G. G., Zhang, Y., and Zheng, Q. L.
- Subjects
- *
GEOLOGICAL basins , *SEDIMENTARY facies (Geology) , *PACIFIC Plate , *PLATE tectonics - Abstract
The East China Sea Shelf Basin (ECSSB), the Pearl River Mouth Basin (PRMB) and the Taixinan Basin (TXNB) in the northern continental margin of the South China Sea (SCS) are important oil- and gas-bearing basins on the Western Pacific Continental Margin. During the Paleocene to Late Miocene, their strata can be compared, and the lithofacies were continuous from the TXNB, via the Taixi Basin (TXB) to the ECSSB. The lithologies mainly consist of interbedded shale, sandstone and mudstone layers. In addition, these basins have similar tectonic and sedimentation features. The three basins had similar marine-terrigenous facies in the Paleocene and marine-lacustrine-fluvial facies during the Eocene and Late Miocene. The basins experienced several coeval tectonic movements and episodes, and they developed a series of NE- and NNE-trending faults during the Paleocene and Eocene, which controlled the structure of the basins. During the Early Oligocene and Middle Miocene, they developed a series of NW- and WNW-trending strike-slip faults, reverse folds and flower-like strike-slip faults. However, there were obvious differences in sedimentary and tectonic evolution since the Late Miocene. The TXNB and TXB developed marine facies after the Late Miocene, while in the Quaternary, open marine facies replaced the Pliocene terrigenous facies in the ECSSB. Since the Late Miocene, the south of the ECSSB developed into a subsidence stage, and fault activity stopped. The TXB and TXNB developed some inverse structures and then developed into a thermal subsidence episode after the Dongsha Movement. Thus, this paper proposes that the ECSSB and the Cenozoic basins in the SCS were originally a unified basin and then subsequently separated into two basins as a result of the indentation of the Philippine Sea Plate (PSP) and the arc-continent collision between the Luzon Arc and the Eurasian Plate. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
32. Final breakup of continental block and opening of oceanic lithosphere: insights from deep crustal structure and tectonic evolution of the ocean-continent transition zone in the northern South China Sea.
- Author
-
Guo, L. L., Li, S. Z., Zhao, S. J., Zhang, G. X., Suo, Y. H., Liu, H., Hui, G. G., Fu, S. Y., Dai, L. M., Cao, H. H., Li, X. Y., Wang, P. C., and Wang, Q.
- Subjects
- *
LITHOSPHERE , *PLATE tectonics , *RIFTS (Geology) , *SPREADING centers (Geology) - Abstract
As an important transition domain between the thinnest continental crust and the initial oceanic crust, the ocean-continent transition zone (OCT) preserves a wealth of information on the processes of lithospheric extension and breakup. The northern margin of the South China Sea (SCS) is a non-typical, magma-poor passive continental margin with a particular structural pattern and sedimentary formation. The OCT in the northern margin of the SCS was developed by a series of continental rifting and seafloor spreading. Based on several multi-channel seismic reflection profiles, crustal-scale structural profiles extracted from gravity data and ocean-bottom seismometers (OBS) data, this paper studies the deep crustal structures, deformation and geodynamics of the OCT to further understand the structural patterns and tectonic process from the lithospheric extension to its breakup. The OCT of the northern margin of the SCS is characterized by a crustal thinning and high-velocity layer (HVL) in the lower crust. The OCT has three structural units: rift depression, volcanic zone and tilted fault blocks. The HVL is mainly limited in the eastern portion of the northern SCS. The HVL is distributed essentially within the OCT but does not clearly develop everywhere in the OCT. We propose a hybrid model of rifting to fit characteristics of the northern margin of the SCS. A crustal-scale largely symmetric process predominated at the initial rifting stage. The basin-controlling faults subsequently penetrated the entire crust, resulting in asymmetric tectonic evolution. Then, the OCT occupied this asymmetric location. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
33. Definition of South China Sea Monsoon Onset and Commencement of the East Asia Summer Monsoon.
- Author
-
Wang, B., LinHo, Yongsheng Zhang, and Lu, M.-M.
- Subjects
- *
MONSOONS , *SUMMER , *CLIMATOLOGY , *METEOROLOGY - Abstract
The climatological mean summer monsoon onset in the South China Sea (SCS) is a remarkably abrupt event. However, defining onset dates for individual years is noticeably controversial. The controversies and complications arise primarily from a number of factors: the intermittent southward intrusion of cold fronts into the northern SCS, the bogus onset in late April before the establishment of tropical monsoons over Indochina, and active intraseasonal oscillation. In this paper, a simple yet effective index, U[sub SCS] , the 850-hPa zonal winds averaged over the central SCS (5°–15°N and 110°–120°E), is proposed for objectively defining the SCS monsoon onset. This onset index depicts not only the sudden establishment of the tropical southwesterly monsoon over the SCS but also the outbreak of the rainy season in the central-northern SCS. In this paper the East Asian summer monsoon (EASM) is defined as the broadscale summer monsoon over East Asia and the western North Pacific region (0°–40°N, 100°–140°E). It is shown that the seasonal transition of EASM can be objectively determined by the principal component of the dominant empirical orthogonal mode of the 850-hPa zonal winds, U[sub EOF1] . It is found that the local index U[sub SCS] represents U[sub EOF1] extremely well; thus, it can be used to determine both the SCS onset and the commencement of the broadscale EASM. The result suggests that the SCS summer monsoon onset indeed signifies the beginning of the summer monsoon over East Asia and the adjacent western Pacific Ocean. Evidence is also provided to show the linkage between the two salient phases of EASM: the local onset of the SCS monsoon and the local onset of the mei-yu (the rainy season in the Yangtze River and Huai River basin and southern Japan). [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
34. The Agreements and Disputes Crystalized by the 2009-2011 Sino-Philippine Exchange of Notes Verbales and their Relevance to the Jurisdiction and Admissibility Phase of the South China Sea Arbitration.
- Author
-
Gau, Michael Sheng-ti
- Subjects
- *
INTERNATIONAL arbitration , *JURISDICTION , *ADMISSIBLE evidence , *DISPUTE resolution , *TREATIES - Abstract
This paper examines the evidences used by the Tribunal for the South China Sea Arbitration to conclude that Philippines' Submissions 3-4 and 6-7 reflect disputes. The Jurisdictional Award uses certain notes verbales sent by the Philippines and China in April 2011 for this purpose. However, the plain wording of these notes verbales negates the existence of disputes concerning the legal status of nine maritime features identified by those four Submissions. The Tribunal overlooks the agreement reached in these notes verbales that some geological features in the Kalayaan Islands Group may generate Exclusive Economic Zone and continental shelf, which serve to defeat Philippines' Submissions 5, 8, and 9 as well as the Philippines' theory that China invokes historical rights to justify its law enforcement activities in the entire region within the U-Shaped Line. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
35. Expansions and Restrictions in the UNCLOS Dispute Settlement Regime: Lessons from Recent Decisions.
- Author
-
Klein, Natalie
- Subjects
- *
DISPUTE resolution , *JURISDICTION , *DECISION making in law , *ARCTIC Sunrise Seizure, 2013 ,UNITED Nations Convention on the Law of the Sea (1982) - Abstract
Recent decisions under the UNCLOS dispute settlement regime, such as Chagos Archipelago, Arctic Sunrise and South China Sea, have had cause to consider the parameters of jurisdiction that exists under Part XV of UNCLOS. A determination of jurisdiction for any court or tribunal constituted under UNCLOS must have regard to alternative means of dispute settlement available, whether the dispute is one relating to the interpretation or application of UNCLOS and whether any exceptions to jurisdiction apply. This paper will consider these three dimensions in light of recent decisions and reflect on ways that the scope of jurisdiction is being expanded or restricted to resolve the disputes at issue. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
36. The Role of Southwesterly Flow in MCS Formation During a Heavy Rain Event in Taiwan on 12 - 13 June 2005.
- Author
-
Fang-Ching Chien
- Subjects
- *
RAINFALL , *MESOSCALE convective complexes , *HYDRAULICS , *VORTEX motion , *SYNOPTIC climatology - Abstract
This paper presents a numerical study of a heavy rain event that occurred in southern Taiwan in June 2005. From 11 - 13 June 2005, a weak Mei-yu front moved southeastward from China to Taiwan, while mesoscale convective systems (MCSs) were developing and moving northward over the northern South China Sea (SCS). During the first day of the event the southwesterly flow intensified when a ridge associated with the Pacific high extended northwestward from the Philippines to the southern Taiwan Strait (TS). This pressure pattern produced a large northwestward pressure gradient force that created a southeasterly wind speed increase followed by intensification of the southwesterly flow through Coriolis acceleration. An low-level jet (LLJ) formed consequently and transported moisture and unstable air toward the southwestern coast of Taiwan. MCSs were triggered in the southwesterly flow because the potentially unstable air was lifted in a low-level convergence and shearing vorticity environment. They intensified, became organized, and moved northeastward overland, resulting in heavy rainfall in southern Taiwan. On the second day, low pressure formed near the southern TS because of the combined effect of a travelling short-wave trough and a pressure reduction resulting from the latent heat release by the evolving MCSs. This pressure change produced down-gradient acceleration in the northeastward direction, resulting in southwesterly flow strengthening. The local wind acceleration was smaller than that of the first day because the dominant pressure system was local scale, while that of the first day was synoptic scale. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
37. Structures and characteristics of the windy atmospheric boundary layer in the South China Sea region during cold surges.
- Author
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Cheng, Xue-Ling, Wu, Lin, Huang, Jian, and Zeng, Qing-Cun
- Subjects
- *
TURBULENCE , *MARINE resources conservation , *ATMOSPHERIC boundary layer , *ATMOSPHERIC circulation , *MARINE ecology - Abstract
An observational analysis of the structures and characteristics of a windy atmospheric boundary layer during a cold air outbreak in the South China Sea region is reported in this paper. It is found that the main structures and characteristics are the same as during strong wind episodes with cold air outbreaks on land. The high frequency turbulent fluctuations (period <1 min) are nearly random and isotropic with weak coherency, but the gusty wind disturbances (1 min
- Published
- 2015
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- View/download PDF
38. A Real-Time Regional Forecasting System Established for the South China Sea and Its Performance in the Track Forecasts of Tropical Cyclones during 2011-13.
- Author
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Peng, Shiqiu, Li, Yineng, Gu, Xiangqian, Chen, Shumin, Wang, Dongxiao, Wang, Hui, Zhang, Shuwen, Lv, Weihua, Wang, Chunzai, Liu, Bei, Liu, Duanling, Lai, Zhijuan, Lai, Wenfeng, Wang, Shengan, Feng, Yerong, and Zhang, Junfeng
- Subjects
- *
WEATHER forecasting , *TROPICAL cyclones , *MARINE ecology , *ECOLOGICAL disturbances - Abstract
A real-time regional forecasting system for the South China Sea (SCS), called the Experimental Platform of Marine Environment Forecasting (EPMEF), is introduced in this paper. EPMEF consists of a regional atmosphere model, a regional ocean model, and a wave model, and performs a real-time run four times a day. Output from the Global Forecast System (GFS) from the National Centers for Environmental Prediction (NCEP) is used as the initial and boundary conditions of two nested domains of the atmosphere model, which can exert a constraint on the development of small- and mesoscale atmospheric perturbations through dynamical downscaling. The forecasted winds at 10-m height from the atmosphere model are used to drive the ocean and wave models. As an initial evaluation, a census on the track predictions of 44 tropical cyclones (TCs) during 2011-13 indicates that the performance of EPMEF is very encouraging and comparable to those of other official agencies worldwide. In particular, EPMEF successfully predicted several abnormal typhoon tracks including the sharp recurving of Megi (2010) and the looping of Roke (2011). Further analysis reveals that the dynamically downscaled GFS forecasts from the most updated forecast cycle and the optimal combination of different microphysics and PBL schemes primarily contribute to the good performance of EPMEF in TC track forecasting. EPMEF, established primarily for research purposes with the potential to be implemented into operations, provides valuable information not only to the operational forecasters of local marine/meteorological agencies or international TC forecast centers, but also to other stakeholders such as the fishing industry and insurance companies. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
39. Role of the 10-20-day oscillation in sustained rainstorms over Hainan, China in October 2010.
- Author
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Qiao, Yunting, Zhang, Chunhua, and Jian, Maoqiu
- Subjects
- *
RAINSTORMS , *RAINFALL , *ATMOSPHERIC circulation , *OSCILLATIONS - Abstract
Hainan, an island province of China in the northern South China Sea, experienced two sustained rainstorms in October 2010, which were the most severe autumn rainstorms of the past 60 years. From August to October 2010, the most dominant signal of Hainan rainfall was the 10-20-day oscillation. This paper examines the roles of the 10-20-day oscillation in the convective activity and atmospheric circulation during the rainstorms of October 2010 over Hainan. During both rainstorms, Hainan was near the center of convective activity and under the influence of a lower-troposphere cyclonic circulation. The convective center was initiated in the west-central tropical Indian Ocean several days prior to the rainstorm in Hainan. The convective center first propagated eastward to the maritime continent, accompanied by the cyclonic circulation, and then moved northward to the northern South China Sea and South China, causing the rainstorms over Hainan. In addition, the westward propagation of convection from the tropical western Pacific to the southern South China Sea, as well as the propagation farther northward, intensified the convective activity over the northern South China Sea and South China during the first rainstorm. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
40. Response of dissolved oxygen and related marine ecological parameters to a tropical cyclone in the South China Sea.
- Author
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Lin, Jingrou, Tang, Danling, Alpers, Werner, and Wang, Sufen
- Subjects
- *
MARINE ecology , *TROPICAL cyclones , *DISSOLVED oxygen in water , *PARAMETER estimation , *OCEAN temperature - Abstract
Abstract: It is well known that tropical cyclones can cause upwelling, decrease of sea surface temperature, increase of chlorophyll-a (Chl-a) concentration and enhancement of primary production. But little is known about the response of dissolved oxygen (DO) concentration to a typhoon in the open ocean. This paper investigates the impact of a typhoon on DO concentration and related ecological parameters using in situ and remote sensing data. The in situ data were collected 1week after the passage of the super-typhoon Nanmadol in the northern South China Sea in 2011. An increase in DO concentration, accompanied by a decrease in water temperature and an increase in salinity and Chl-a concentration, was measured at sampling stations close to the typhoon track. At these stations, maximum DO concentration was found at a depth of around 5m and maximum Chl-a concentration at depths between 50 and 75m. The layer of high DO concentration extends from the surface to a depth of 35m and the concentrations stay almost constant down to this depth. Due to the passage of the typhoon, also a large sea level anomaly (21.6cm) and a high value of Ekman pumping velocity (4.0×10−4 ms−1) are observed, indicating upwelling phenomenon. At the same time, also intrusion of Kuroshio waters in the form of a loop current into the South China Sea (SCS) was observed. We attribute the increase of DO concentration after the passage of the typhoon to three effects: (1) entrainment of oxygen from the air into the upper water layer and strong vertical mixing of the water body due to the typhoon winds, (2) upwelling of cold nutrient-rich water which stimulates photosynthesis of phytoplankton and thus the generation of oxygen, which also increases the DO concentration due to cold water since the solubility of oxygen increase with decreasing water temperature, and, possibly, (3) transport of DO enriched waters from the Western Pacific to the SCS via the intrusion of Kuroshio waters. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
41. An Analysis of a Severe Turbulence Event Encountered by an Aircraft over the South China Sea and the Application of Numerical Weather Prediction Models in the Early Alerting of the Event.
- Author
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Chan, P. W. and Wong, W. K.
- Subjects
- *
TURBULENCE , *WEATHER forecasting , *COMPUTER simulation , *AIR traffic , *METEOROLOGY , *CUMULONIMBUS - Abstract
In the literature, there is rather limited number of accounts of significant turbulence over the South China Sea, which is an area of busy air traffic. The present paper documents the meteorological observations of an aircraft over the seas west of the Philippines on encountering severe turbulence associated with an area of convection. From the valuable flight data available from this aircraft, it is found that, on encountering the significant turbulence, the aircraft experienced increase in wind speed, strong downdraft, high windshear hazard factor, and, most importantly, high level of eddy dissipation rate, which is a measure of turbulence intensity in civil aviation. The application of numerical weather prediction (NWP) models in the forecasting of this severe turbulence case is also studied. It turns out that the cumulonimbus extent and in-cloud turbulence potential products from World Area Forecast System may have some indication of the occurrence of significant turbulence associated with convection in the area concerned. A mesoscale NWP model even forecasts the possibility of moderate-to-severe turbulence about 24 to 27 hours ahead of the event. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
42. The effect of inhomogeneous water on seismic imaging in deepwater areas of the South China Sea.
- Author
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Ji, LiLi, Lin, Mian, and Hao, TianYao
- Subjects
- *
IMAGING systems in seismology , *UNDERWATER imaging systems , *PARTIAL differential equations , *SOUND pressure , *SEISMIC waves - Abstract
This paper examines the effect of inhomogeneous water on seismic imaging in deep water areas. An appropriate partial differential equation is derived for the acoustic pressure field in inhomogeneous water, including current effects. Seismic wavefields are simulated and the results show that the traveltime of seismic waves can be affected. The maximum traveltime perturbation at zero offset is 20 ms. In particular, the structure of horizontal reflectors below the water is distorted by mesoscale eddies. Variations of water temperature are the fundamental cause of the distortion. Finally, a calibration method for the distortion of seismic imaging caused by inhomogeneous water is presented. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
43. Analysis of deep-layer and bottom circulations in the South China Sea based on eight quasi-global ocean model outputs.
- Author
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Xie, Qiang, Xiao, JinGen, Wang, DongXiao, and Yu, YongQiang
- Subjects
- *
OCEAN bottom , *SALINITY , *SCIENTIFIC observation , *SIMULATION methods & models , *OCEAN surface topography - Abstract
This study is a preliminary analysis of the South China Sea (SCS) deep circulations using eight quasi-global high-resolution ocean model outputs. The goal is to assess models’ ability to simulate these deep circulations. The analysis reveals that models’ deep temperatures are colder than the observations in the World Ocean Atlas, while most models’ deep salinity values are higher than the observations, indicating models’ deep water is generally colder and saltier than the reality. Moreover, there are long-term trends in both temperature and salinity simulations. The Luzon Strait transport below 1500 m is 0.36 Sv when averaged for all models, smaller compared with the observation, which is about 2.5 Sv. Four assimilated models and one unassimilated (OCCAM) display that the Luzon deep-layer overflow reaches its minimum in spring and its maximum in winter. The vertically integrated streamfunctions below 2400 m from these models show a deep cyclonic circulation in the SCS on a large scale, but the pattern is different from the diagnostic streamfunction from the U.S Navy Generalized Digital Environment Model (GDEM-Version 3.0, GDEMv3). The meridional overturning structure above 1000 m is similar in all models, but the spatial distribution and intensity below 1500 m are quite different from model to model. Moreover, the meridional overturning below 2400 m in these models is weaker than that of the GDEMv3, which indicates a deep vertical mixing process in these models is biased weak. Based on the above evaluation, this paper discusses the impacts of T/S initial value, topography, and mixing scheme on the SCS deep circulations, which may provide a reference for future model improvement. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
44. Origin, transport, and vertical distribution of atmospheric pollutants over the northern South China Sea during the 7-SEAS/Dongsha Experiment.
- Author
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Wang, Sheng-Hsiang, Tsay, Si-Chee, Lin, Neng-Huei, Chang, Shuenn-Chin, Li, Can, Welton, Ellsworth J., Holben, Brent N., Hsu, N. Christina, Lau, William K.M., Lolli, Simone, Kuo, Chun-Chiang, Chia, Hao-Ping, Chiu, Chia-Yang, Lin, Chia-Ching, Bell, Shaun W., Ji, Qiang, Hansell, Richard A., Sheu, Guey-Rong, Chi, Kai-Hsien, and Peng, Chi-Ming
- Subjects
- *
ATMOSPHERIC deposition , *VERTICAL distribution (Aquatic biology) , *BIOMASS burning , *ATMOSPHERIC aerosols - Abstract
During the spring of 2010, comprehensive in situ measurements were made for the first time on a small atoll (Dongsha Island) in the northern South China Sea (SCS), a key region of the 7-SEAS (the Seven South East Asian Studies) program. This paper focuses on characterizing the source origins, transport processes, and vertical distributions of the Asian continental outflows over the region, using measurements including mass concentration, optical properties, hygroscopicity, and vertical distribution of the aerosol particles, as well as the trace gas composition. Cluster analysis of backward trajectories classified 52% of the air masses arriving at ground level of Dongsha Island as having a continental origin, mainly from northern China to the northern SCS, passing the coastal area and being confined in the marine boundary layer (0–0.5 km). Compared to aerosols of oceanic origin, the fine mode continental aerosols have a higher concentration, extinction coefficient, and single-scattering albedo at 550 nm (i.e., 19 vs. 14 μg m−3 in PM2.5; 77 vs. 59 Mm−1 in βe; and 0.94 vs. 0.90 in ω , respectively). These aerosols have a higher hygroscopicity (f at 85% RH = 2.1) than those in the upwind inland regions, suggesting that the aerosols transported to the northern SCS were modified by the marine environment. In addition to the near-surface aerosol transport, a significant upper-layer (3–4 km) transport of biomass-burning aerosols was observed. Our results suggest that emissions from both China and Southeast Asia could have a significant impact on the aerosol loading and other aerosol properties over the SCS. Furthermore, the complex vertical distribution of aerosols-coinciding-with-clouds has implications for remote-sensing observations and aerosol–cloud–radiation interactions. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
45. Author Correction: The emergence of Miocene reefs in South China Sea and its resilient adaptability under varying eustatic, climatic and oceanographic conditions.
- Author
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Mathew, Manoj, Makhankova, Adelya, Menier, David, Sautter, Benjamin, Betzler, Christian, and Pierson, Bernard
- Subjects
- *
OCEANOGRAPHY , *CORAL reefs & islands - Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
46. Author Correction: Deep-sea Sediment Resuspension by Internal Solitary Waves in the Northern South China Sea.
- Author
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Jia, Yonggang, Tian, Zhuangcai, Shi, Xuefa, Liu, J. Paul, Chen, Jiangxin, Liu, Xiaolei, Ye, Ruijie, Ren, Ziyin, and Tian, Jiwei
- Subjects
- *
SEDIMENTARY basins - Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
47. Mechanisms for the Advanced Asian Summer Monsoon Onset since the Mid-to-Late 1990s*.
- Author
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Xiang, Baoqiang and Wang, Bin
- Subjects
- *
MONSOONS , *WATER management , *PRECIPITATION (Chemistry) , *FARM management - Abstract
Understanding the variability and change of monsoon onset is of utmost importance for agriculture planning and water management. In the last three decades, the Asian summer monsoon onset (ASMO) has remarkably advanced, but the physical mechanisms underlying the change remain elusive. Since the overall ASMO occurs in May, this paper focuses on the change of mean fields in May and considers enhanced mean precipitation and monsoon westerly winds as signs of advanced ASMO. The results reveal that the advanced ASMO mainly represents a robust decadal shift in the mid-to-late 1990s, which is attributed to the mean state change in the Pacific basin characterized by a grand La Niña-like pattern. The La Niña-like mean state change controls the ASMO through the westward propagation of Rossby waves and its interaction with the asymmetric background mean states in the Indian Ocean and western Pacific, which intensifies the Northern Hemispheric perturbations and westerly winds. Intriguingly, the abrupt decadal shifts of monsoon onset in the Arabian Sea and Bay of Bengal occur in 1999, in contrast to the South China Sea with a decadal shift in 1994. Numerical experiments with a coupled climate model demonstrate that the advanced monsoon onset in the Arabian Sea and Bay of Bengal is governed by the enhanced zonal sea surface temperature (SST) gradients in the equatorial Pacific, while that in the South China Sea is primarily determined by the abrupt SST warming near the Philippine Sea. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
48. Passive seismic experiment and ScS wave splitting in the southwestern subbasin of South China Sea.
- Author
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Ruan, AiGuo, Li, JiaBiao, Lee, ChaoShing, Qiu, XueLin, and Pan, ShaoJun
- Subjects
- *
SEISMOLOGY , *OCEAN waves , *DATA analysis , *EARTHQUAKE intensity , *BROADBAND communication systems , *ANISOTROPY , *SHEAR waves - Abstract
The seismic experiment of 3D array of OBS in the southwestern sub-basin of the South China Sea (SCS) is briefly introduced in this paper. The data analysis of broadband OBS shows that totally 93 earthquakes with magnitude of Ms 6.0-6.9 and 10 earthquakes with magnitude above Ms 7.0 were recorded in high quality during this experiment, especially the catastrophic earthquake Ms 9.0 occurred in the east sea area of Japan on March 11, 2011. The anisotropy parameters inversion of ScS wave of four events above Ms 7.0 indicates that the fast direction of shear wave is N58°E parallel to the ceased spreading ridge of the southwestern sub-basin of SCS (the slow direction is S35°E perpendicular to the spreading ridge), which means the spreading ridge is under compressing stress at present and the cessation of seafloor spreading is related to such stress field as well. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
49. Risk assessment for Liwan relief well in South China Sea
- Author
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Zhang, Hui, Gao, Deli, and Liu, Wensheng
- Subjects
- *
DRILLING & boring , *RELIEF wells , *RISK assessment , *ANALYTIC hierarchy process , *ACCIDENTS - Abstract
Abstract: Drilling engineering has a great amount of uncertainty and always involves huge investments and high risks. The term “relief well” refers to a well drilled from a secure area that intersects with an accident well. It is a key method to effectively deal with a blowout or fire hazard by using a well kill operation. Due to drilling uncertainty, a relief well assumes significant responsibility to cope with potential accidents during onshore and offshore drilling. Thus failure of the relief well leads to more serious consequences than caused by original accident. It is essential to analyze and assess the relief well risk before the drilling operation in order to prevent complex accident, improve drill efficiency and guarantee the rescued project will work smoothly. Based on Analytic Hierarchy Process (AHP) method and fuzzy set theory, this paper proposes a comprehensive risk assessment model of relief well, then applies the model to evaluate the drilling risk of LW21-1-1 relief well project in South China Sea. The assessment results demonstrate that the success rate of drilling this relief well is estimated at 48.7%, providing needed informational base to take decisions about controlling existing risks and therefore to drastically decrease wasted time, further accidents and direct financial losses. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
50. Recent Sino-Italian collaborative studies on marine organisms from the South China Sea.
- Author
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Yue-Wei Guo, Gavagnin, Margherita, Carbone, Marianna, Mollo, Ernesto, and Cimino, Guido
- Subjects
- *
MARINE organisms , *BIOACTIVE compounds , *NATURAL products , *MOLLUSKS , *STEREOCHEMISTRY , *CIRCULAR dichroism , *MOLECULAR structure - Abstract
In this communication, selected results obtained in the course of a 10-year Sino- Italian collaborative project are presented. During this collaboration, several studies on marine organisms collected in the South China Sea have been conducted, resulting in the characterization of a large number of novel natural products. The main interest has been focused on sponges, cnidarians, and molluscs. Here, the recent research, including some not yet published studies, on cnidarians and molluscs, in particular, opisthobranchs and pulmonates, will be briefly described. The study of cnidarians and pulmonates led to isolate molecules, in particular, biscembranoids and polypropionates, displaying carbon skeletons already described in previous papers. Our studies resulted in their complete structural characterization including the absolute stereochemistry that was clarified by coupling X-ray diffraction to circular dichroism (CD) spectra analysis. Some unique nitrogenous molecules containing either an isonitrile function or an 1,2,4-oxadiazole moiety, this latter found for the first time in a marine organism, as well as known sesterterpenoids and diterpenoids were isolated from opisthobranchs. Owing to their anatomical location, these metabolites should play a relevant role in the protection of the molluscs. Finally, a series of alkaloids structurally related to known anticancer agents were also characterized. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
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