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The article presents the "Position Paper of the Government of the People's Republic of China on the Matter of Jurisdiction in the South China Sea Arbitration Initiated by the Republic of the Philippines," as of September 2016. Topics include a lawsuit filed by Philippines against China under the e United Nations Convention on the Law of the Sea; and significance of the arbitration in terms of the territorial sovereignty over several maritime features in the South China Sea.

The capillary pressure curve is a crucial basis for studying the pore structure and multiphase flow characteristics in oil and gas reservoirs. Due to the loose and unconsolidated nature of the clayey-silt sediment of natural gas hydrate reservoirs in the South China Sea, conventional methods such as mercury intrusion and centrifugation struggle to obtain capillary pressure curves for these sediments. In this study, X-ray diffraction analysis, scanning electron microscopy, nitrogen adsorption, and water-gas contact angle measurements are utilized to characterize the mineral composition, pore structure, pore size distribution, and wettability of the clayey-silt sediment. Subsequently, the filter paper method from soil mechanics is employed to determine the capillary pressure curve for the clayey-silt samples. The results indicate that the capillary pressure curve obtained through the filter paper method exhibits a saturation range of 18.39%-80.31% and a capillary pressure range of 19.04 to 46,481.42 kPa. It exhibits a distinct two-stage characteristic, where capillary pressure changes rapidly with water saturation below 61.05% and slowly above 61.05%. The pore radius calculated from the capillary pressure curve ranges from 2.41 nm to 5.91 µm. This alignment with the pore ranges obtains from nitrogen adsorption and Scanning Electron Microscopy confirms the accuracy of the obtained capillary pressure curve. Furthermore, in comparison with a literature capillary pressure curve obtained through centrifugation, the paper filtration method covers a broader range, providing better representation of capillary pressure in the multiscale pores of clayey-silt samples. [ABSTRACT FROM AUTHOR]

Internal wave distribution maps have been compiled from more than one hundred ERS-1/2, RADARSAT and Space Shuttle SAR images in the South China Sea (SCS) from 1993 to 2000. Based on these distribution maps, most of the internal waves in the north-east part of the SCS were propagating westward. The wave crest can be as long as 200 km with an amplitude of 100 m, due to strong current from the Kuroshio branching out into the SCS. In a recent SCS internal wave study, moorings were deployed in April 1999 and 2000. Simultaneous SAR coverage from ERS-2 and RADARSAT were also collected. The ERS-2 high-resolution SAR images collected from the Taiwan ground station were processed in near real-time to coordinate the field test. SAR data are then used to compare with mooring data. SAR data and Acoustic Doppler Current Profiler (ADCP) data show internal solitons induced by the semi-diurnal tides with a wave speed of 2.4 m s -1 . [ABSTRACT FROM AUTHOR]

Natural gas hydrate reservoirs in the northern South China Sea primarily comprise clayey silt, making exploitation more challenging relative to sandy reservoirs in other countries and regions. This paper provides an overview of the latest research developments in the exploitation mechanism covering the past five years, focusing on hydrate phase transition, multiphase flow in the decomposition zone, the seepage regulation of reservoir stimulation zone, and production capacity simulation, all of which are relevant to the previously conducted two rounds of hydrate trial production in offshore areas of China. The results indicate that the phase transition of clayey-silt hydrate remains in a dynamic equilibrium, with the decomposition efficiency mainly controlled by the coupling of heat and flow and high heat consumption during decomposition. The decomposition zone exhibits strong hydrophilicity, easy adsorption, and sudden permeability changes. A temperature drop is present that is concentrated near the wellbore, and once a water lock has formed, the gas-phase flow capacity significantly decreases, leading to potential secondary hydrate formation. To enhance permeability and increase production, it is imperative to implement reservoir and temperature field reconstruction based on initial formation alterations, which will further optimize and improve the transport capacity of the reservoir. [ABSTRACT FROM AUTHOR]

The experimental testing and analysis of strength and deformation characteristics of hydrate reservoirs is an integral part of natural gas hydrate exploitation. However, studies so far have failed to deeply explore samples from the South China Sea. Especially, there is a lack of a simple and applicable method to estimate their mechanical behaviors. Thus, based on test data, an improved Duncan-Chang model is established in this paper to characterize the strength and deformation of reconstituted samples with various hydrate saturation and stress states from this area. This model can accurately describe the strainhardening characteristics, and failure strength is estimated by the improved Drucker-Prager criterion with high fitting accuracy. The initial elastic modulus and failure ratio are given by the proposed empirical models, which are obtained from experimental data and fitting methods. Generally, this model has several advantages including simple structure, favorable performances, and a limited number of model parameters. Therefore, it could be widely used in strength and deformation analysis. This study can support the prevention and control of geological risks during natural gas hydrate exploitation in the South China Sea. [ABSTRACT FROM AUTHOR]

The South China Sea (SCS), situated in southern China, at the junction of the Pacific Plate, the Eurasian Plate, and the Indian Ocean Plate, is a northeast-southwest trending semi-enclosed sea. It spans an area of approximately 3.5 million square kilometers and has an average water depth of about 1 200 m, its deepest point reaching 5 559 m. In 2021, a scientific expedition (called as U1 voyage) in the South China Sea was organized by the Innovation Research Team of Guangdong Special Key Program from March to April, this marks the first comprehensive scientific research voyage to the southern U-boundary corridor. Consisting of a total of 30 papers, this special issue is to share a portion of the research findings from this scientific expedition U1 voyage, covering six aspects: 1) characteristics of the marine ecosystem in the SCS and its response to marine dynamic processes; 2) multi-scale marine dynamic processes, sea-air interactions, and forecasting techniques in the SCS; 3) geomorphology and geological structure; 4) sedimentary processes and resource potential in the SCS; 5) geostrategy, rights and interests maintenance and strategic countermeasures in the SCS; 6) marine scientific instruments. By integrating the scientific research with the study of history, jurisprudence and international strategies, this issue presents new insights into the formation history and scope evolution of the SCS, and it also seeks to establish a new scientific framework based on the marine governance and development of the SCS. [ABSTRACT FROM AUTHOR]

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]

Spirit writing is a rare form of trance mediumship in contemporary urban Hanoi and part of the resurgence of popular religious practices in late Socialist Vietnam. This article explores the transmission of otherworldly messages from heroic political and military leaders of the past via an urban female spirit medium and examines practices of translation, decoding and implementing celestial directives. Based on ethnographic fieldwork, the paper investigates how efforts to execute instructions from the beyond are intertwined with mediation, materiality, and technology. Drawing on an analysis of messages from the spirit of Hồ Chí Minh and other heroes of the past, this paper argues that spirits interfere in Vietnam's current political matters by questioning issues of injustice and by advising the authorities with regard to ritually safeguarding the country's borders. [ABSTRACT FROM AUTHOR]

After being a neutral actor for decades in the complex South China Sea (SCS) territorial disputes, Indonesia has seen itself compelled by China's assertiveness to become firmer about protecting its territorial sovereignty around the Natuna Islands (NI). Jakarta is alarmed by China's claims that it has undeniable historical fishing rights in the NI territorial waters because they undermine Indonesia's territorial sovereignty. Our analysis loosely adopts the securitization conceptual framework proposed by the Copenhagen School to reveal that Jakarta swiftly securitized the NI issue between 2014 and 2016. Using a combination of quantitative and qualitative methods, this paper unpacks how the Indonesian printed mainstream media discussed the NI in recent years. By the end of 2016, the Indonesian media portrayed China's claims that it has historical fishing rights in the NI territorial waters as the most urgent national security threat to Indonesia, i.e. the NI issue was securitized. This analysis shows that the Indonesian people accepted Jakarta's security discourse, i.e. Jakarta had successfully securitized China's claims over the NI territorial waters. This paper makes a new contribution to the securitization literature by simultaneously analysing the Indonesian news and social media outlets. [ABSTRACT FROM AUTHOR]

Abstract The Late Cretaceous is a significant geologic period in the South China Sea area, as it marks the tectonic transition from the early Paleo-Pacific Plate subduction to the subsequent Cenozoic rifting related to the opening of the SCS. However, the Late Cretaceous tectonic evolution of the South China Sea area is yet to be clearly defined, and it is at present largely debated in the literature. In this paper, mainly on the basis of ~240,000 km2 newly acquired 3D seismic reflection data, 94 industrial wells and existing U Pb ages of basement granitoids, we carried out an integrated interpretation, mapping and analysis of the pre-Cenozoic (> 66 Ma) structures within the basement of the Cenozoic rift basin in the northern South China Sea area, that can be crucial for a broad understanding of the Late Cretaceous tectonic evolution of this region. Results of this analysis suggest that three Late Cretaceous fault systems can be identified in the northern South China Sea margin: 1) the WNW-striking thrust system, 2) ENE-striking extensional fault system, and 3) ENE-striking thrust system. These three fault systems are considered to have developed in the Late Cretaceous since they are superimposed on the well dated Late Jurassic to Early Cretaceous (161.6–101.7 Ma) arc-related granitoids that define most of the basement of the Cenozoic rift basin within the study area. This new structural evidence, combined with a review of previous studies, led us to propose a renewed multi-phase geodynamic evolutionary model of the South China Sea area during the Late Cretaceous. The first tectonic event that can be recognized generated the WNW-striking thrust system and is, in this paper, interpreted to have formed as a result of a sinistral transpressional event that took place in the South China Sea area and adjacent areas around 100 Ma at the Early-Late Cretaceous boundary. This transpressional event was likely related to intense oblique convergence between the Paleo-Pacific Ocean Plate and the Eurasia Plate. The second tectonic phase that was identified in this paper (~100 Ma to ~72 Ma) is defined by an extensional event that generated the largely ENE-striking extensional fault systems and associated basins, which is interpreted to be related to the back-arc extension that took place in this period in response to the slab roll back and high-angle subduction of the Paleo-Pacific Plate. This extensional phase eventually led to the opening of the Proto-South China Sea on the SE margin of the proto-South China Block, and it should be distinguished from the Cenozoic rifting phases that are related to the opening of the South China Sea. The third and last tectonic phase that was recognized in this paper is a compressional event that took place in the late stage of the Late Cretaceous (~72 Ma to ~66 Ma) and was responsible for the development of the ENE-striking thrust system. We suggest that this post-subduction (post-Yanshanian) compressional event can be interpreted to have developed in response to process of ridge push related to the sea floor spreading of the Proto-South China Sea. Highlights • Two Late Cretaceous (K 2) thrust systems and one extensional fault system are identified in the northern SCS area • A sinistral transpressional event at the Early-Late Cretaceous boundary in response to a change in plate configuration • An episode of regional extension related to the back-arc extension in the early K 2 in the SCS area • A previously unrecognized compressional event caused by ridge push process of the Proto-SCS opening in the late K 2 • A renewed multi-phase geodynamic evolutionary model of the SCS area during the Late Cretaceous [ABSTRACT FROM AUTHOR]

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]

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]

China's claim to a large part of the South China Sea (SCS) is indicated by a specific cartographic convention, the U-shaped (or dashed) line, shown on its official maps. The line has become an important element in Western popular discourse concerning the geopolitics of the SCS. This paper argues that the cartographic re-presentation of the U-shaped line in the Western press contributes to an 'orientalist' conception that portrays China as 'other'; as aggressive and unwilling to 'play by the rules', and a portrayal of the whole region as potentially unstable. Its re-circulation may, however, work to China's advantage by reinforcing cartographic precedent and creating a specific 'geographic imagination' of the SCS. Maps are regarded as an important element in the 'spectacle of fear' propagated by the West, with the representations of the SCS shown to be part of a wider use of maps by the press to cover issues related to geopolitics and conflict. [ABSTRACT FROM AUTHOR]

This study examines whether the pacifying effect of foreign direct investment (FDI) on territorial disputes between adversarial dyads is conditional upon the dyads' past experience of military cooperation. I built a political economy model and conducted a logistic regression analysis on the newly coded bilateral FDI data between adversarial dyads and the existing dataset by merging the rivalry data established by Thompson [51] and the territorial disputes data collected by Lee and Mitchell [42]. I found that when bilateral FDI flows between adversarial dyads reach a certain level the pacifying effect of FDI is stronger for adversarial dyads with past military cooperation. I also found that while past military cooperation has a pacifying effect in general, past military cooperation that occurred more recently has a stronger pacifying effect than those that occurred a while ago. Moreover, based upon the theoretical model and empirical findings in this paper, I investigated the political implications for Tsai Ing-wen's "New Southbound Policy" and Taiwan's approach to the territorial dispute issues in the South China Sea. [ABSTRACT FROM AUTHOR]

Conventional accounts of the South China Sea territorial disputes identify China's assertive behaviour as the primary cause of the rising tension since the early 2010s. This paper goes beyond this traditional interpretation of the disputes by arguing that the territorial disputes are an expression of the broader contestation between two order-building projects by China and the United States (US). China's assertive behaviour originates in its desire to promote a 'historical' and 'post-colonial' maritime order that is premised on its Sino-centric historical narrative of the Sea and on its emphasis on the historical legitimacy of the regional order of 1943–1945. The US-led 'liberal' maritime order is underpinned by a post-war legal framework built on the San Francisco Peace Treaty and the United Nations Convention on the Law of the Sea, and the notion and practice of freedom of navigation. Since October 2015 the US has enhanced its freedom of navigation operations to challenge China's 'excessive' maritime or territorial claims. We conclude that as a result of the uneasy coexistence of these two order-building projects, which fundamentally disagree over the foundations of maritime order in the South China Sea, the disputes have reached an open-ended impasse. [ABSTRACT FROM AUTHOR]

The safety of navigation remains an issue in the sense that navigation through the South China Sea is essential for world seaborne trade and communications, and the lingering territorial and maritime disputes would constitute a threat to the safety of navigation there. In recent years, the term 'freedom of navigation' has become a pivotal expression in the rivalry between China and the United States in the South China Sea. This paper starts with addressing the international legal framework concerning navigation, followed by state practice in the South China Sea, including domestic legislation and safety measures. It then discusses the issue of military activities in the exclusive economic zone and their implications for the freedom of navigation. The paper identifies several issues connected to navigation, such as the U-shaped line, law enforcement patrols, and the recent South China Sea Arbitration. A brief conclusion is provided at the end. [ABSTRACT FROM AUTHOR]

One of the most significant events in China's history of engaging international law was its legal defeat in the South China Sea Arbitration case. The case was brought by the Republic of Philippines on its disputes with China concerning maritime entitlements in the South China Sea. The Arbitral Tribunal ruled in favor of the Philippines, first on the jurisdiction and admissibility issues in October 2015, and finally on the merits in July 2016. China not only refused to accept the Tribunal's authority, but also vigorously attacked the final award as being invalid and even illegal. This paper critically examines the different views, particularly the Chinese perspectives, on three major legal aspects of this case, including (1) the legitimacy of the Arbitral Tribunal, (2) whether the Tribunal had jurisdiction over the case, and (3) whether the Tribunal erred in applying UNCLOS on certain important legal issues concerning the merits of the case, in light of the two awards (the SCS Jurisdiction Award and the Merit Award) and the relevant rules and doctrines in international law. The paper then argues that, while the Tribunal's own legitimacy seems to be unquestionable, whether it had jurisdiction over the dispute is debatable. Most likely it has, but China's certain arguments against the jurisdiction are worthy of discussion. However, the final award's interpretation and application of certain provisions of UNCLOS are problematic and possibly erroneous. The analysis, however, suggests that China would have been in a much better position on the legal front had it formally participated in the case from the jurisdictional stage. Finally, the paper discusses the implication of the arbitration on China's attitude toward international law. [ABSTRACT FROM AUTHOR]

This paper addresses developments following the final arbitration ruling from The Hague, issued in July 2016, on the South China Sea dispute between China and the Philippines. It considers the impact on the region of U.S. responses to the ruling and analyzes Washington's interests in the South China Sea: to preserve a rules-based order, support friends and allies, and preserve freedoms of navigation. However, pursuit of these interests can have an adverse impact on relations between the U.S and China, and affect the ability of these major powers to deal with the bigger issues of North Korea and Taiwan. Calls for the Trump Administration to take a stronger stand in the South China Sea in pursuit of these interests have not always been well received in the region. As a consequence, Southeast Asian countries are increasingly hedging against further deterioration in China-U.S. relations. The paper concludes that rather than acting more strongly against China in the South China Sea, there would be benefit in the U.S. taking a more constructive role by supporting current efforts towards better cooperation between the littoral countries. [ABSTRACT FROM AUTHOR]

The most challenging task in creating peace in the South China Sea is how to deal with Chinese assertive behavior. This is important since many proposals of the regional security architecture have failed to engage China in order to establish a long-lasting peace in the region. This paper seeks to explain the failure of security management in the South China Sea. Using the concept of strategic culture deriving from constructivism in International Relations, this paper argues that China's strategic culture is the main factor behind the aggressive behavior in the South China Sea. This culture is rooted from the pre-modern China's history that has distinct perspective from the Westphalian international law with regard to territorial disputes. This cultural dimension, not the material one, is the key to rethinking security management in the region. [ABSTRACT FROM AUTHOR]

An anticyclonic eddy's periphery is characterized by large horizontal density gradients, strain and vertical velocity. In this paper we document the asymmetric distribution of phytoplankton around the periphery of anticyclonic eddies in the western South China Sea based on 432 eddies detected from satellite data. The high level of phytoplankton occurs consistently at the northwestern periphery of eddies, with a maximum positive chlorophyll anomaly greater than 0.01 mg m −3 . The asymmetric distribution of phytoplankton primarily tags the non-uniform surface velocity field varying from 0.15 m s −1 to 0.3 m s −1 along the eddy's periphery. The coastal boundary and off-coast jet may be the primary cause of the non-uniform flow. Associated with the non-uniform flow speed, the combined effects of the velocity convergence and steepened northwestern part of the eddies act to sharpen the density fronts and tend to result in an ageostrophic secondary circulation at the northwestern edge of the eddy. The upward component of the ageostrophic secondary circulation can enhance the nutrient flux into the euphotic layer, thereby increasing phytoplankton productivity. Anticyclonic eddy-induced ageostrophic secondary circulation appears to be an important mechanism for increasing phytoplankton productivity in the oligotrophic waters of the South China Sea. [ABSTRACT FROM AUTHOR]

The recent award by an arbitral tribunal in a case brought by the Philippines against China gives lawyers reason to reexamine the historical evidence put forward by claimants in the South China Sea disputes. While the Tribunal was barred from considering territorial or boundary questions, it did cast doubt on the historical narrative rule that China has asserted in support of its claims. Fresh evidence from other sources also suggests that discussions of these matters need to move beyond arguments put forward in a small number of papers published more than thirty years ago. A close examination of the references used in those papers shows that they relied upon highly partisan Chinese sources. Recent historical research has produced new facts about the development of the competing territorial claims in the South China Sea, but international legal discourse has yet to take these findings into account. This article examines some of the key works in the field and calls for them to be reassessed and for future discussion of the disputes to be based upon verifiable and contextualized evidence rather than on nationalist assertions. [ABSTRACT FROM AUTHOR]

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]

There have been recent claims in the media that Great Britain and other nations who operate Freedom of Navigations Operations 'FONOPS' in the South China Sea have taken no stance concerning the sovereignty of the three island groups that are the subject of dispute among the PRC, Philippines, and Vietnam. This paper investigates those claims through examination of the historical record from 1930 to 1941, during the Sino-Japanese conflict that was the East Asian precursor to World War Two. It utilises publications and statements made by a variety of government officials for findings of fact and continuity among nations, which can be seen by the International Court of Justice 'ICJ' and other judicial bodies as recognition by a reasonable person in being. Through an application of applicable laws and court findings, it utilises the results of the examination to arrive at an equitable viewpoint, in line with the statements made by British, Chinese, French, and Japanese officials in the course of their duties. The article finds that there was an overwhelming burden of evidence to support a finding that these nations have historically taken a stance concerning the sovereignty of now disputed island groups in the South China Sea. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The organic matter was from terrestrial and marine sources in SW sub-basin of SCS. • TOC, total n-alkanes, TFA decreased from the margins to the center of the sub-basin. • Correlation of TOC and TFA shows a balance of ocean production and deposition rates. Abstract Information about ocean evolution and material-energy exchange between the ocean and surrounding continents can be preserved in marine sediments. The Southwest Sub-basin, located among the Xisha Islands, the Zhongsha Islands, and the Nansha Islands, is an ideal tectonic unit to analyze the sedimentary environments of the South China Sea. In this paper, the distribution patterns of lipid biomarkers and their compound-specific stable carbon isotopes in surface sediments from the Southwest Sub-basin of the South China Sea were analyzed. Lipid biomarkers are composed of different proportions of aliphatic hydrocarbons, carboxylic acids, alcohols and series of sterols, indicating that the organic matter of the Southwest Sub-basin was derived from marine bacteria, algae and terrestrial higher plants. The average concentration of total organic carbon (TOC) in the study samples was 0.5 ± 0.16%. TOC, total n -alkanes, and total carboxylic acids (TFA) decreased gradually from the margins to the center of the sub-basin, whereas the content of total n- alkanols increased. The spatial distribution trends resulted from varying water depths and the contribution of terrestrial organic matter. The concentration of TFA and the TFA/TOC revealed that the accumulation of organic matter in this area was generally low. The strong correlation between TOC and TFA of surface sediments in the study area may be related to a balance between the ocean production and ocean deposition rates. [ABSTRACT FROM AUTHOR]

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]

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]

In this paper, we have conducted a probabilistic tsunami hazard assessment (PTHA) for Hong Kong (China) and Kao Hsiung (Taiwan), considering earthquakes generated in the Manila subduction zone. The new PTHA methodology with the consideration of uncertainties of slip distribution and location of future earthquakes extends the stochastic approach of Sepúlveda et al. (2017). Using sensitivity analyses, we further investigate the uncertainties of probability properties defining the slip distribution, the location, and the occurrence of earthquakes. We demonstrate that Kao Hsiung and Hong Kong would be significantly impacted by tsunamis generated by MW > 8.5 earthquakes in the Manila subduction zone. For instance, a specific MW 9.0 earthquake scenario is capable of producing tsunami amplitudes exceeding 4.0 and 3.5 m in Kao Hsiung and Hong Kong, respectively, with a probability of 50%. Despite the significant tsunami impact, great earthquakes have long mean return periods. As a result, the PTHA shows that Kao Hsiung and Hong Kong are exposed to a relatively small tsunami hazard. For instance, maximum tsunami amplitudes in the assessed locations of Kao Hsiung and Hong Kong exceed 0.32 and 0.18 m, respectively, with a mean return period of 100 years. The inundation hazard in populated areas is small as well, with mean return periods exceeding 1,000 years. Sensitivity analyses demonstrate that the PTHA can be affected by the uncertainties of the probability properties defining the slip distribution, the location, and the occurrence of earthquakes. However, PTHA results are most sensitive to the choice of the earthquake occurrence model. Key Points: Probabilistic tsunami hazard assessment in Kao Hsiung and Hong Kong for tsunamis generated in the Manila subduction zoneConsistent methodology for probabilistic tsunami hazard assessment with consideration of uncertain earthquake slip distribution and locationAnalysis of the uncertainties associated with the probability properties of the earthquake slip distribution, location, and occurrence [ABSTRACT FROM AUTHOR]

Abstract The hydrocarbon exploration from low permeability (<50mD) reservoirs in Beibuwan Basin has been on the agenda because of the production decline of old wells and the growing demand of fossil fuel with the rapid economic development of China. However, these low permeability reservoir rocks usually exhibit strong heterogeneity and the complicated pore structure of these rocks, which significantly affects the reservoir quality, is still unclear. This study attempts to reveal the pore structure of low permeability Eocene Liushagang Formation reservoir rocks from Weixinan and Wushi subbasins in Beibuwan Basin quantitatively and qualitatively using high pressure mercury intrusion porosimetry (HPMIP), N 2 adsorption and field emission-scanning electronic microscopy (FE-SEM). Our results show that macropores (>50 nm) mainly contribute to the total pore spaces for most samples with lower shale content; mesopores(2–50 nm) dominate the pore spaces of samples with higher shale content, which leads to the relatively large surface area of these samples; permeability of these low permeability rocks is positively related with average pore-throat radius and negatively related with relative sorting coefficient while no such a close relationship exists between permeability and porosity; fractal dimension has a negative relationship with average pore-throat radius and permeability. In summary, this work comprehensively investigates the pore structure characteristics of low permeability Liushagang Formation reservoir rocks from Beibuwan Basin using multiple complementary approaches, which helps to further understand the hydrocarbon migration and accumulation mechanism of these low permeability reservoirs. Highlights • This paper comprehensively characterized the pore structure characteristics of low permeability rocks. • The relationships among permeability, pore size, fractal dimension were investigated. • HPMIP and N 2 adsorption methods provided different fractal dimensions and the reason was discussed. • The shale content was found to affect the pore structure of these low permeability rocks significantly. [ABSTRACT FROM AUTHOR]

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]

Abstract In this paper, internal solitary waves (ISWs) in the northern South China Sea (NSCS) are investigated with respect to their propagation and evolution processes in different months. To achieve that, environmental parameters associated with ISW are first calculated using climatological datasets derived from the Simple Ocean Data Assimilation 3.3.1 (SODA3.3.1) reanalysis. The environmental parameters are significantly distinct from month to month, especially the quadratic nonlinearity coefficient α. It is negative in the deep basin and turns positive on the shallow continental shelf. A clear dividing line that α equals to zero can be found along the shelf from northeast to southwest from January to February and from October to December. The dividing line is interrupted starting from March and is mostly constrained on the northeast shelf, and from May to September only limited areas can positive α be found. Further simulations based on the variable extended Korteweg-de Vires (veKdV) model indicate that the polarity conversion process of ISWs therefore exhibits significant seasonality. It can be concluded from the simulation results that near the 200-m isobath on the continental shelf the elevation waves are more likely to appear from November to March owing to the positive values of α. The large-scale background current exhibits little effect on the deformation and polarity conversion of ISW in the NSCS although it prominently affects the environmental parameters around the shelf currents from Luzon strait. Highlights • ISWs in the NSCS are investigated with respect to their propagation and evolution processes in different months. • A parametric study and simulation of ISW reveal that elevation waves are more likely to appear in November to March. • The polarity conversion depth of ISW in different months as well as its variation is determined. [ABSTRACT FROM AUTHOR]

The slow moving conflict in the South China Sea has been characterized by some as “not worth the candle.” China claims the entirety of the South China Sea pursuant to a nine-dash line, the legal impact of which has been limited by international courts. At the same time, China has changed the reality of control over the South China Sea by building a number of fortified islands in the Spratly Islands and elsewhere. The US has either refused to stand up to China's behavior (Obama) or responded unevenly (Trump). This paper examines the impact of China's behaviour on local parties, US interests, and the liberal international system. [ABSTRACT FROM AUTHOR]

In contemporary international security, some powers try to challenge the status quo through gradual, sub-threshold expansion without resorting to the explicit use of force. Examples of such sub-threshold challenges can be seen in the East China Sea, the South China Sea, and Eastern Europe. They are now referred to as 'gray zone' or 'hybrid threat'. For a long time deterrence theory, a core component of strategic studies, has largely neglected such sub-threshold challenges. The exceptional part of that is empirical school's findings, including fait accompli, limited probe, and controlled pressure. They perfectly match with the current threats and help developing conceptual framework to deter these kind of threats. Based on these findings, this paper attempted to illustrate three principles for gray zone deterrence: combination of deterrence by denial and deterrence by punishment, mobilization of the whole government assets, and keeping open the window to escalation and analyze, Japan's efforts to develop conceptual framework for gray zone deterrence. Since Japan's efforts to develop conceptual framework of gray zone deterrence dates further back than other part of the world, as the National Defense Program Guidelines (NDPG) of 2010, a case study on Japan would provide useful insights for gray zone deterrence. [ABSTRACT FROM AUTHOR]

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]

At a time when the focus of most of the academic research on China is on the geopolitical developments in the South China Sea and the panning out of the United States' “next phase of rebalance strategy” in Asia, this paper draws attention to China's charm offensive across the Atlantic. It explores the political undertones of China's soft power push in the developed western world, especially in the context of its evolving relationship with the United States. In the final section, the paper tracks the implication of these developments on India and Indian policymaking. [ABSTRACT FROM PUBLISHER]

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]

Deep oil and gas resources in the South China Sea have drawn increasing attention in recent years, involving several essential challenges such as favorable zone prediction, deep burial, poor data quality, non-homogeneous reservoir properties, low drilling rate, and the low research degree of Paleozoic strata. These issues vastly affect the exploration and development of deep oil and gas resources in this area. Specifically, the Lufeng and Huizhou Depressions exhibit rich hydrocarbon accumulation and distribution areas in the Pearl River Mouth Basin, thereby possess great resource potential. The seven papers discussed here propose a set of practical techniques that can be applied to the exploration of deep Paleogene in the shallow layers of the Pearl River Mouth Basin. All of these works make important contributions deepening the theory of Paleogene reservoir formation and promoting further exploration of Paleogene in the Pearl River Mouth Basin, to increase the hydrocarbon storage and production prospects. [ABSTRACT FROM AUTHOR]

The Kuroshio carrying the northwestern Pacific water intrudes into the South China Sea (SCS) through the Luzon Strait, significantly affecting the temperature, salinity, circulation, and eddy generation in the SCS. Thus, the Kuroshio intrusion makes important contributions to the momentum, heat and salt budgets in the SCS. In the past decades, much work has been done on the Kuroshio intrusion. This paper reviews past efforts and summarizes our current understanding of the Kuroshio intruding processes from observational evidence, laboratory results, theoretical analyses, and a range of numerical model simulations. In addition, discrepancies between results simulated by models, as well as those between simulations and observations, are presented. Specifically, this paper addresses the following topics: (1) different types of the Kuroshio intrusion into the SCS and their identification, (2) vertical structure of the Kuroshio in the Luzon Strait, (3) an overview of the Luzon Strait transport resulting from observations and numerical model simulations, (4) seasonal and interannual variations of the Kuroshio intrusion, as well as eddy generation due to the Kuroshio path variation, and (5) dynamical mechanisms ( e.g. , wind forcing, interbasin pressure gradient, β effect and hysteresis, potential vorticity, eddy activity) controlling the Kuroshio intrusion into the SCS. Finally, several future research topics for gaining a better understanding of the Kuroshio intruding processes are suggested. [ABSTRACT FROM AUTHOR]

Much has been made over the past few years of China'vs ambitions of regaining control of its irredentist claims in the East and South China Seas. While some of this speculation focuses on the massive amounts of money the People's Republic of China (PRC) has funneled into its naval modernization program, other analysts are more interested in the drivers behind the increasingly popular sentiment that the country must “reclaim” its lost territories. The Chinese Communist Party can ill afford to ignore the voice of an already disenchanted population if it hopes to stay in power, particularly in regard to matters of national pride. As a result, in dealing with China's irredentist claims, nationalism in particular can be a powerful ideological factor in shaping the nation's foreign policies. This is especially apparent in the case of irredentism, where nationalism can often override diplomatic and strategic imperatives. This paper addresses the question of how does the nationalist discourse vary between two territorial disputes, the East and South China Seas. It uses discourse analysis to examine developing trends among online social media and news sites. This in turn allows for the construction of a framework of how nationalism develops among both elite and grassroots audiences. [ABSTRACT FROM PUBLISHER]

As deep-sea engineering develops, it becomes essential to analyze the stability of submarine slopes when considering the stability of submarine foundations or evaluating the safety of offshore structures. However, the traditional method for analyzing slope stability does not give adequate consideration to the uncertainty of soil properties, and so the reliability method has been proposed and used to settle the variation of soil parameters. Regarding the northern slope of the South China Sea, the present paper summarizes its geomorphic features, seismic characteristics, and the soil strength at certain boreholes. A typical slope section is chosen with which to conduct probability analysis using the polynomial-based Response Surface Method (RSM) and the Advanced First Order Second Moment method(AFOSM). A novel form of the RSM based on Gaussian Process Regression (GPR) is also proposed and applied in this case to approximate the limit state function, and its efficiency is confirmed. The simulation results of Latin-hypercube analysis are set as the benchmark for the other methods. The influences of slope gradient and seismic action on the stability of submarine slopes are also investigated. [ABSTRACT FROM AUTHOR]

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]

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]

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]

For the first time, Hong Kong Observatory conducted a full scale dropsonde observation of the circulation of a tropical cyclone, namely, Tropical Storm Aere, on 7 October 2016, over the northern part of the South China Sea. This paper documents the observations and their use in the prediction of the track and strength of the tropical cyclone in a numerical weather prediction model. In addition to the model analysis fields, the dropsonde observations are found to provide further information about the structure of Aere. The quality of the dropsonde data was found to be satisfactory in comparison with the radiosonde data nearby. The dropsonde data were found to have a positive impact on the prediction of the track of the tropical cyclone, improving track location accuracy by about 13%. The prediction of the strength of Aere was found to have a higher dependence on the assimilation of the wind field than the assimilation of the humidity field. [ABSTRACT FROM AUTHOR]

Influenced by the seasonally reversed monsoons, water exchange through straits, and topography, the shelf and slope circulation in the northern South China Sea (NSCS) is complex and changeable. The typical current system in the NSCS consists of the slope current, South China Sea warm current (SCSWC), coastal current, and associated upwelling (in summer) and downwelling (in winter). This paper reviews recent advances in the study of NSCS shelf and slope circulation since the 1990s, and summarizes the roles of Kuroshio intrusion, the monsoons, topography, and the buoyancy effect of the Pearl River plume in the shelf and slope current system of the NSCS. We also point out some potential scientific issues that require further study, such as the dynamic connection between the internal basin and shelf areas of the NSCS, the persistence of the SCSWC in winter, the temporo-spatial characteristics of downwelling during winter in the NSCS, and its material and energy transport. [ABSTRACT FROM AUTHOR]

The status of maritime features is one of the core issues in the South China Sea Arbitration. The essence of this issue is territorial sovereignty and maritime delimitation disputes between China and the Philippines. Based on the interception of certain facts and evidence, the Tribunal did not interpret the China's diplomatic position as it wanted, and it had an intensely subjective interpretation of Article 121(3) of the United Nations Convention on the Law of the Sea of 1982. Combined with the Chinese government's positions before and after the publicity surrounding the Award, this paper, which takes the logical approaches of the Award as the main line, focuses on chapter 6 of the Award, raising questions about disputes on the status of maritime features, analyzing the treaty interpretations related to the status of maritime features, and clarifying the defections. [ABSTRACT FROM AUTHOR]