Xianglong Jin

Discussion on Development of Ocean Exploration Technologies and Equipments

Firstly,strategic demands of ocean exploration technologies and equipments in four aspects are analyzed,including ocean exploitation and economic growth,maritime rights and interests maintenance and maritime security,construction of ocean ecological civilization and marine scientific progress.Secondly,the current situation of ocean exploration technologies and equipments is reviewed,and development tendency is pointed out.Lastly,according to status of ocean exploration technologies and equipments in China,existing problems are presented,and advices and measures are proposed.

Preliminary considerations on the potential influence of submarine fans on marine delimitation

The complex issues associated with marine delineation for the outer limit of continental shelf and the boundary delimitation have provoked considerable attention among researchers in a variety of academic circles, particularly in the juristic filed and the geo-science field. In the present contribution, we start from an overview of submarine fans, as one of common types of sediment-deposit bodies in the ocean, and explore the related geological features which may be of relevance to the marine delimitation in accordance with the 1982 United Nations Convention on the Law of the Sea. We carry out a comparative assessment of certain significant geological features of submarine fans, using the Bengal fan as an example, which is the biggest submarine fan in the world and represents an important factor in the maritime boundary dispute between the neighboring states currently. The relationship between the special geological bodies and the international principle in the 1982 United Nations Convention can be established by combining geological and juristic analyses. This preliminary observation on the effect of submarine bodies both on the marine entitlement and boundary delimitation indicates that it is important for the international society to appropriately deal with this problem so that the marine right of any state can be protected.

The spatial multiscale variability of heavy metals based on factorial kriging analysis: A case study in the northeastern Beibu Gulf

Factorial kriging analysis is applied to the research on the spatial multiscale variability of heavy metals in submarine. It is used to analyze the multiscale spatial structures of seven heavy metals, Ni, Cu, Zn, Pb, Cr, As and Cd in the surface sediment from the northeastern of Beibu Gulf, identify and separate spatial variations at different scales of heavy metals, and discuss the provenance of heavy metals and the influencing factors. The results show that the existence of three-scale spatial variations those consist of nugget effect, a spherical structure with range of 30 km (short-range scale) and a spherical structure with range of 140 km (long-range scale) in the linear model of coregionalization fitted. The spatial distribution features of seven heavy metals at short-range scale reflect “spot-like” or “stripe-like” local-scale spatial variations; the spatial distribution features of the seven heavy metals at long-range scale represent “slice-like” regional-scale spatial variations. At local scale, Zn, Cr, Ni, Cu, Pb and Cd are derived primarily from parent materials of Hainan Island, Leizhou Peninsula and Guangxi land, whose spatial distribution characteristics are controlled by granularity of sediments, while As is influenced dominantly by human pollution components from Hainan Island and Leizhou Peninsula. At regional scale, Zn, Cr, Ni and Cu originate primarily from parent rock materials of Leizhou Peninsula and Hainan Island, secondly from Guangxi land; As originated primarily from parent rock materials from Hainan Island, secondly from Leizhou Peninsula and Guangxi land. These metals are transported and migrated with sediments dominated by the anticlockwise circulation of Beibu Gulf year-round, deposited in “convergence center”, forming the whole sedimentary pattern in direction of NWW-NNW at regional scale. The difference in distribution type between As and other metals at regional scale is mainly due to their different geochemical behavior.

Tephra records from abyssal sediments off western Sumatra in recent 135 ka: evidence from Core IR-GC1

Three volcanic ash layers were identified in a deep-sea Core IR-GC1 from the north-eastern Indian Ocean, adjacent to western Indonesian arc. They were dominated by glass shards with minor mineral crystals, such as plagioclase, biotite, and hornblende. According to the morphology and major element compositions of the representative glass shards, combined with the 18O-based age, it is suggested that ash Layer A is correlated to the youngest Toba tuff (YTT), Layer B is supposed to be associated with a new eruption of Toba caldera in an age of 98 to 100 ka. Ash Layer C is different the geochemistry characteristics than those of Layer A and Layer B, suggesting that Layer C was not originated from Toba but registered another volcanic eruption event.

Effect of natural prolongation with geological features on maritime delimitation

The United Nations Convention on the Law of the Sea entitled the coastal States to naturally extend the continental shelf, which has caused more drastic disputes of maritime delimitation. This paper devotes to clarifying the significant concept of natural prolongation through an effect method combing the legal principles and technical analysis. Firstly, the classic samples with respect of the development of geological features are traced. Based on these samples, the classification with a model is proposed in order to affirm the concept’s significance under certain geomorphologic situations. Lastly, scientific analysis is used to present two potential prolongation situations and emphasize that all the technical analysis on maritime delimitation should be complied with international law and protect the common interest of all the mankind.

Methods and procedures to determine the outer limits of the continental shelf beyond 200 nautical miles

This paper establishes techniques and methods to determine a variety of boundaries associated with 200 nautical miles beyond the continental shelf. The methods, based on topography, slope and second-derivative profile integrated analysis, are now able to identify automatically the foot of the continental slope (FOS). By analyzing the sedimentary profile, the points of 1% sediment thickness are recognized. Through the intersection, cut, deletion and mergence calculation of the extrapolated data set of fixed-point series, the method succeeds in generating automatically the extrapolated boundaries, including the FOS+60 M line, the 350 M line, and the 2 500 m+100 M line. In addition, based on the automatic analysis of the topographic profile, it can be applied to determine rapidly the points of maximum water depth. Taking the northern Okinawa Trough (OT) as an example, these methods are used to calculate and examine the boundaries included in the Submission by the People’s Republic of China Concerning the Outer Limits of the Continental Shelf beyond 200 Nautical miles in Part of the East China Sea (ECS); the boundaries thus derived have a solid scientific and rational basis.

Recent progress in submarine geosciences in China

In China submarine geosciences represents a newly established discipline of oceanography, focusing on the oceanic lithosphere, and its interface with the hydrosphere and biosphere. Recently, supported by the National High Technology Research and Development Program and other high-tech development projects, significant progress has been made in the development of advanced technologies and equipment. This enables the scientists in China to carry out explorations of the international seabed area in the Pacific Ocean and on the Southwest Indian Ridge. In addition, they have been active in the research activities associated the mid-ocean ridges and western Pacific marginal seas. It is anticipated that this research field will continue to be highly fruitful in the near future.

Automatic Detecting Outliers in Multibeam Echo Sounding Data

Advances in technology and more exacting requirements for hydrographic survey have led to greatly increasing data rates and densities for new generation multibeam systems. It needs rapidly to process the large datasets. However, interactive plot is employed to edit data manually in some hydrographic software. The efficiency is too low. Therefore, some automatic and rapid approaches must be developed. In this paper, an automatic algorithm for detecting outliers is proposed. The algorithm avoids the slow and long time in manual editing. The interactively editing theory is used to automatically detect large and collective outliers, so it is robust. Erosion and dilation effectively retain the normal data which is separated from main block. The result of median filter is not ultimate result, and it is only used to calculate local variance, so distortion in details is avoided and the little outliers are located. It is one kind of postprocessing method. The algorithm is verified by some data and proved to be rapid, robust and able to automatically process large quantities of data.