渤海学:新世纪渤海国研究的一把钥匙

渤海国是唐及五代时期中国东北地区的一个地方民族政权,是7—10世纪中国东北乃至东北亚地区的一颗灿烂明珠。至今,古渤海国历史、文化仍吸引着许多热心的中外专家、学者;古渤海国文物、古迹成为中外旅游者追踪的目标;生长在渤海故土上的人们更是眷恋着这片流油的黑土地。尽管历尽沧桑东北亚的政治地图在近、现代发生了重大变化,历史上的渤海国疆土已一分为三,出现在中国、朝鲜和俄罗斯三国的版图上;尽管渤海国的研究者们分属于不同的国家、民族,在渤海国的一些主要问题上观点相左:尽管保存下来的有关渤海国的文献资料不多(迄今为止。

渤海新史料辨证一题

渤海历史研究史料缺乏,新史料非常重要。但是我们对新史料应采取谨慎的态度,加强对新史料的研究,注意其真伪、用途、历史背景和作用等。本文挑选一条新史料试加辨证,目的在于提醒学界慎重对待新史料,同时充分发挥真品的史料价值。

渤海国历史及文化特点研考

本文介绍了渤海国建立的历史及文化特点,将渤海国研究纳入渤海学是新世纪渤海国研究的重要方法。

Seasonal cycle of topography in the Bohai Sea and Yellow Sea and its relationships with atmospheric forcing and oceanic adjustment based on altimetry data

Seasonal cycle is the most significant signals of topography and circulation in the Bohai Sea (BS)and Yellow Sea (YS) forced by prevailing monsoon and is still poorly understood due to lack of data in their interiors. In the present study, seasonal cycles of topography in the BS and YS and its relationship with atmospheric forcing and oceanic adjustment were examined and discussed using TOPEX/Poseidon and ERS-1/2 Sea Level Anomalies (SLA) data. Analyses revealed complicated seasonal cycles of topography composed mainly of2 REOF modes, the winter-summer mode (WIM) and spring-autumn mode (SAM). The WIM with action center in the BS displayed peak and southward pressure gradient in July, and valley and northward pressure gradient in January, which is obviously the direct response to monsoon with about 1-month response time. The SAM with action center in the western south YS displayed peak and northward pressure gradient in October and valley and southward pressure gradient in April. After the mature period of monsoon, the action center in the BS became weakened while that in the western south YS became strengthened because of regional convergence or divergence induced by seasonal variations of the Taiwan Warm Current and Yellow Sea Coastal Current. The direct response of topography to monsoon resulted in the WIM, while oceanic adjustment of topography played an important role in the forming of the SAM.

Forms of phosphorus and silicon in the natural grain size surface sediments of the southern Bohai Sea

The forms of phosphorus and silicon in the natural grain sizes surface sediments of the southern Bohai Sea were studied. In sediments, the organic matter bound form of phosphorus was the main form of transferable phosphorus and ranged from 0.37 μmol/g to 1.57 μmol/g, accounting for 10.7% of the total phosphorus, others were the carbonate bound form, iron manganese oxide bound form and ion exchange able form; the transferable form of phosphorus accounted for 19.2% of the total phosphorus. Silicon’s carbonate bound form was predominant over others among its transferable forms, and content ranged from 1.55 μmol/g to 8.94 μmol/g, accounting for 0.05% of the total silicon; the total amount of transferable silicon forms accounted for only 0.12% of the total silicon. Therefore, 19.2% of the total phosphorus and 0.12% of the total silicon contained in the surface sediments of the southern Bohai Sea could participate in the biogeochemical cycling.

Species and distribution of inorganic selenium in the Bohai Sea

For studying geochemical behavior of selenium, a marine investigation was conducted in September 1998 cruise in the Bohai Sea. Horizontal and vertical distributions of inorganic selenium and selenite were studied. The inorganic selenium varied from 0.73 to 2.41 nmol/L, with an average of 1.31 nmol/L; while selenite varied from 0.18 to 0.72 nmol/L with an average of 0.47 nmol/L. The average ratio of selenite to selenate was 0.68, and selenate was the predominant species of inorganic selenium in the most study area. Concentrations of inorganic selenium and selenite decreased with distance from the coast. No apparent variations of the concentration between surface and bottom was shown. There were two wa- ter masses in the area, one from the Huanghe (Yellow) River and other from the Yellow Sea. Of the two, Huanghe River was the major source of inorganic selenium.

Impact of tropical cyclone Matmo on mixed zone of the Yellow and Bohai Seas

The Bohai Sea is a low-lying semi-enclosed sea area that is linked to the Yellow Sea via the Bohai straits(mixed zone). Its of fshore seabed is shallow, which makes it vulnerable to serious marine meteorological disasters associated with the northward passage of Pacific tropical cyclones. Analyses on data of remote sensing and buoy of the mixed zone of the Yellow and Bohai seas indicate that all the wind speed, significant wave height, and salinity(SAL) increased, sea surface temperature decreased, and wind energy density changed considerably during the passage of tropical cyclone Matmo on July 25, 2014. It was found that the SAL inversion layer in the mixed zone of the Yellow and Bohai Seas was caused by the tropical cyclone. Furthermore, it was found that the tropical cyclone transported the northern Yellow Sea cold water mass(NYSCWM) into the mixed zone of the Yellow and Bohai Seas. The NYSCWM has direct influence on both the aquaculture and the ecological environment of the region. Therefore, further research is needed to establish the mechanism behind the formation of the SAL inversion layer in the mixed zone, and to determine the influence of tropical cyclones on the NYSCWM.

Taxonomic reexamination of the genus Chirolophis in China waters

The present paper deals with the taxonomic reexamination and description of two species of Chirolophis collected in Chinese waters from the Bohai Sea and the Yellow Sea. C. japonicus Herzenstein, 1890 was previously reported and known by its synonym Azuma emmnion Jordan and Snyder, 1902; C. saitone (Jordan et Snyder, 1902) represents the first record of this species in China from Bohai Sea. A key for their identification and a discussion on all the nominal species and their geographic distribution are provided.

Modeling of the Bohai oilfield engineering geology demonstration information system based on digital seabed technology

In this paper, the framework and technologic process of engineering geology demonstration information system （EGDIS） of the Bohai oilfield are presented, and the key technologies for system modeling, such as storage and processing technology of multi-source and heterogeneous data, integrated display technology of multi-source information and multiple safeguard system design are studied. EGDIS of the Bohai oilfield is an integrated application system based on the data standardization and digital seabed database, has the function to realize the standardization/conformity, input/output, inquiry and display of the multi-source and heterogeneous data and graphics, and provides multiple comprehensive analysis and application services, which will provide shared and scientific basic data for the marine engineering construction and oilfield engineering safeguard.

Barotropic current fluctuations coupled with sea level drawdown in Yellow and Bohai Seas

Sub-tidal barotropic current variations coupled with residual sea level fluctuation in the Bohai and Yellow Seas during wintertime are addressed in this study.The temporal evolution and spatial distribution of current fluctuation are investigated using moored acoustic Doppler current profiler data in a three-dimensional numerical model.It is found that a southward current followed by a northward current occurred in the northern Yellow Sea during the fluctuation,concurrent with a significant outflow followed by inflow through the Bohai Strait.The process is consistent from surface to bottom and is coupled with remarkable residual sea level fluctuation.This quasi three-day fluctuation with amplitude 0.2-0.3 m/s leads to 1 m/1.2 m drawdown in the northern Yellow and Bohai Seas,respectively,strongly influencing water exchange between those seas.Because this a prominent feature in the seas,it is necessary to evaluate its effect on fluctuation during winter in future studies,in particular,the northward current during the recovery phase of sea level in the Bohai and Yellow Seas regarding seasonal variation.

Late-stage rapid accumulation of the PL19-3 giant oilfield in an active fault zone during Neotectonism in the Bozhong depression,Bohai Bay

Late-stage is defined here as the period when Neotectonism occurred since 5.1 Ma. Most petroliferous basins in China lie in the areas where Neotectonism occurred intensively. In recent years, Chinese petroleum geologists have paid much attention to late-stage petroleum accumulation. The PL19-3 giant oilfield is situated where faulting activities occurred violently during Neotectonism. To understand the mechanism of lat-stage rapid accumulation, we discussed the most important aspects responsible for the formation of the giant oilfield, including oil generation, active oil-source rock occurrence, fault activity and fault conduits, late-stage rapid oil injection as well as the distinguishing indicators. This study shows that: (1) sufficient oil was supplied to the PL19-3 field since 5.1 Ma because the PL19-3 structure was surrounded by four sags in which three intervals of high-quality source rocks remained active during Neotectonism; (2) densely distributed faults and high porosity/permeability sandstone carrier beds comprised the effective conduit system for oil migration and injection; (3) oil migrated along the faults and charged the PL19-3 structure rapidly by means of seismic pumping which was triggered by frequent earthquakes during Neotetonism. It is documented that elevated reservoir temperature, abnormal geothermal gradients and abnormally high homogenization temperatures of the fluid inclusions are the indicators for late-stage rapid oil accumulation.