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1.
《中国海洋湖沼学报》1984,(1)
It is found that the mud distributions in the Huanghai Sea and East China Sea are extremely identical with the upwelling's in terms of locality and extent. The process of the mud formation is examined. It is concluded that vertical circulation i.e. upwelling plays a determinant role in the: process and furthermore, it is inferred that wherever upwelling occurs on continental shelf, mud should be formed and, conversely, wherever downwelling takes place, mud should not exist, for which coarse: sediment should substitute. 相似文献
3.
Investigations and studies for years all demonstrated that there is a patch of fine-grained mud in the central area of the South Yellow Sea. However, scientists have different opinions on its material source, genesis, and sedimentation intensity. Some believe that the materials come from the Huanghe River, some think that the mud area represents the depocentre of the South Yellow Sea, and some consider it as "relict mud ". The authors ' geochemical study reveals that the mud is multi-sourced, yet the material supply is not ample, and that a little amount of fine-grained suspended materials deposited slowly under the dynamic action of a cyclonic gyre formed the modern muddy sediment, which is named "multi-source modern mud ". 相似文献
4.
It is apparent that there is a difference between mud coasts and sand coasts in such aspects as sediment components, hydrodynamics of nearshore waters, and the formative process in configuration, and profile. The intensity distribution of waves affecting the mud flats in Lianyungang, and the conditions determining tidal water levels, are discussed in this paper. A mathematical model which describes the erosion process of mud flats has been derived on the basis of the results of tests for the mud process in seawater. The model is satisfactory for the actual mud flat profile change in Lianyungang with artificial mud discharges. 相似文献
5.
The circulation of Yellow Sea Cold Water Mass(YSCWM) in the Southern Yellow Sea is investigated using a diagnostic 2D MITgcm model. The resolution of the computational grid is 900 m in the horizontal and 2 m in the vertical where an initial temperature distribution corresponding to a typical measured Yellow Sea Cold Water Mass was applied. The existence of YSCWM that causes fluid density difference, is shown to produce counter-rotating cyclonic horizontal eddies in the surface layer: the inner one is anti-cyclonic(clockwise) and relatively weaker(8–10 cm s-1) while the outer one is cyclonic(anti-clockwise) and much stronger(15–20 cm s-1). This result is consistent with the surface pattern observed by Pang et al.(2004), who has shown that a mesoscale anti-cyclonic eddy(clockwise) exists in the upper layer of central southern Yellow Sea, and a basin-scale cyclonic(anticlockwise) gyre lies outside of the anti-cyclonic eddy, based on the trajectories and drifting velocities of 23 drifters. Below the thermocline, there is an anti-cyclonic(clockwise) circulation. This complex current eddy system is considered to be capable of trapping suspended sediments and depositing them near the front between YSCWM and the coastal waters off the Subei coast, providing an explanation on the sediment depth and size distribution of mud patches in the Southern Yellow Sea. Moreover, sensitive test scenarios indicate that variations of bottom friction do not substantially change the main features of the circulation structure, but will reduce the bottom current velocity, increase the surface current velocity and weaken the upwelling around the frontal area. 相似文献
6.
The Okinawa Trough is a natural laboratory for the study of air-sea interaction and paleoenvironmental change. It has been demonstrated that present offshore export of particles in the bottom nepheloid layer occur primarily with downwelling from the northeast winter monsoon, which is inhibited by a transverse circulation pattern in summer. This current system was very different during the Last Glacial Maximum owing to low sea level(-120 m) and exposure of a large shelf area. We collected sediment core Oki01 from the middle Okinawa Trough during 2012 using R/V K exue No. 1 to elucidate the timing and cause of the current system transition in the East China Sea. Clay mineral, dry density, and elemental(Ti, Ca) composition of core Oki01 was analyzed. The results indicate that clay minerals derived mainly from the Huanghe(Yellow) and the Changjiang(Yangtze) Rivers during 16.0–11.6 ka, and the modern current system in the East China Sea formed beginning in the early Holocene. Therefore, mixing of East China Sea continental shelf, Changjiang River and partially Taiwan Island sediment are the major contributors. The decrease of log(Ti/Ca) and alternating provenance since the early Holocene indicate less sediment from the East China in summer because of resistance of the modern current system, i.e., a "water barrier" and upwelling. Conversely, sediment delivery persists in winter and log(Ti/Ca) indicates the winter monsoon signal since the early Holocene. Our evidence also suggests that sediment from Taiwan Island could be transported by the Kuroshio Current to the middle Okinawa Trough, where it mingles with winter monsooninduced export of sediment from the Changjiang River and East China Sea continental shelf. Although the present research advances understanding of the evolutionary history of paleoenvironmental change in the Okinawa Trough, more sediment cores should be retrieved over wide areas to construct a larger scenario. 相似文献
7.
MOLAR RATIOS OF C, N, P OF PARTICULATE MATTER AND THEIR VERTICAL FLUXES IN THE YELLOW SEA 总被引：2，自引：0，他引：2
The vertical fluxes and molar ratios of carbon, nitrogen and phosphorus of suspended particulate matter in the Yellow Sea were studied based on the analysis of suspended particulate matter,sediments and sinking particles obtained by use of moored sediment traps. The POC ： PON ratios indicate that most of the particulate organic matter in the Yellow Sea water column comes from marine life rather than the continent. The vertical fluxes of SPM, POC, PON and POP in the Yellow Sea are much higher than those in other seas over the world, and present a typical pattern in shallow epicontinental seas. The estimated residence time of the bioactive elements showed that the speed of the biogeochemical process of materials in the Yellow Sea is much shorter than that in the open ocean as there was high primary productivity in this region. 相似文献
8.
Clay minerals and geochemistry of the bottom sediments in the northwestern East China Sea 总被引：1，自引：0，他引：1
Jeungsu YOUN Shouye YANG Yong Ahn PARK 《中国海洋湖沼学报》2007,25(3):235-246
Clay minerals of 34 sediments collected from the northwestern continental shelf of the East China Sea have been determined by X-ray diffraction analysis. The clay mineral distribution is mainly controlled by the sediment source and the dominant circulation pattern. The predominant clay mineral in our study area is illite comprising more than 67% of the whole clay fraction. The highest concentration of illite (>68%) is found in the southeastern offshore parts beyond the reach of terrigenous input from the Jeju Island. It means that these illites are largely transported by the Kuroshio Current from the South China Sea (SCS). Smectite is highly concentrated in the northwest middle part and in the outer-shelf mud patch. It seems to be due to the high supply of smectite transported from China where fine-grained sediments are discharged from modern and ancient Huanghe (Yellow) River. The relatively high abundant kaolinite is likely derived from the Changjiang (Yangtze) River via the Taiwan Warm Current. In contrast, large amounts of chlorite and high chlorite/kaolinite ratios occur in the northwestern area, reflecting the transportation by the Yellow Sea Coastal Current from the southern Yellow Sea. The discrimination diagrams clearly show that the sediments in the northwestern East China Sea are ultimately sourced from Chinese rivers, especially from the Huanghe River, whereas the sediment in the northeast part might come from the Jeju Island. The muddy sediments of the Changjiang River’s submerged delta have much lower 87Sr/86Sr ratios (0.716 2–0.718 0) than those of the Shandong Peninsular mud wedge (0.721 6–0.724 9), which are supposed to be originated from the Huanghe River, suggesting the distribution pattern of 87Sr/86Sr ratios as a new tracer to discriminate the provenance of shelf sediments in the study area. The 87Sr/86Sr ratios of the outer-shelf muddy sediments ranged from 0.7169 to 0.7216 in a wide range and was between those of the Huanghe River and Changjiang River sediments, suggesting multiple sources of the sediment in the area. 相似文献
9.
The East China Sea continental shelf is a unique area for the study of land-sea interactions and paleoenvironmental change because it receives a large amount of terrestrial material inputs. In recent decades, human activities and global climate change have greatly aff ected river discharges into the sea. However, changes in the deposition process caused by these factors in the East China Sea continental shelf are unclear. We collected eight short sediment cores from the East China Sea inner shelf(ECSIS) using a box core sampler in 2012 and 2015. The grainsize, 2 10 Pb, and 1 37 Cs of these cores were analyzed in order to reconstruct the deposition history since the 1950 s, and to reveal human activity and climate change influences on sediment deposition in the ECSIS. Results indicated that sediment grain size became finer after 1969, turned coarser after 1987, and then further coarser since 2003, corresponding well to the three steps of sediment load drop in the Changjiang(Yangtze) River, which are mainly caused by human activities(particularly the closure of the Three Gorges Dam). Simultaneously, the East Asian Monsoon influenced the deposition process in the ECSIS by changing the intensity of coastal currents. Mean grain size variations in the fine-grained population(divided by grain size vs. standard deviation method) coincided with that of the East Asian Winter Monsoon strength and reflected its weakness in 1987. Abrupt changes in sediment grain size over a short time scale in these sediment cores were generally caused by floods and typhoons. Spectral analyses of the sediment cores showed periodicities of 10–11 and 20–22 years, corresponding to the periodicity of solar activity(Schwabe cycle and Hale cycle). Mean grain size time series also displayed a 3–8 year periodicity corresponding to El Ni?o Southern Oscillation periodic change. 相似文献
10.
Numerical simulation of the structure and variation of upwelling off the east coast of Hainan Island using QuikSCAT winds 总被引：3，自引：0，他引：3
The spatial structure and variation of the upwelling in the waters east and northeast of Hainan Island, China during 2000-2007 were investigated using a nested high-resolution Princeton Ocean Model (POM) forced by QuikSCAT winds. The model produced good simulations of the summer upwelling and the seasonal and annual variability. Strong upwelling occurs from mid-July to mid-August with a peak east of Hainan Island associated with the southwesterly monsoon in the South China Sea. Sensitivity experiments indicated that when the local wind stress controls the variability of the upwelling, the large-scale circulation significantly enhances the upwelling northeast of Hainan Island by inducing a local upwelling and transporting cold water northeast-ward along the island’s east coast. The joint effects of the local wind stress and large-scale circulation result in stronger upwelling northeast of Hainan Island. This implies that the annual variation of the upwelling northeast of Hainan Island is controlled not only by the local alongshore wind stress but also by the large-scale circulation. This result will help us investigate the decadal variation of the upwelling in this region in the future. 相似文献
11.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｈｏｒｉｚｏｎｔａｌｃｕｒｒｅｎｔｉｎｔｈｅｓｅａｏｒｏｃｅａｎｉｓａｍａｊｏｒｆａｃｔｏｒａｆｆｅｃｔｉｎｇｓｅｄｉｍｅｎｔｅｒｏｓｉｏｎ ,ｔｒａｎｓ ｐｏｒｔ,ｄｅｐｏｓｉｔｉｏｎ ,ｅｔｃ.Ｔｈｅｒｅｆｏｒｅ,ｍｏｓｔｗｏｒｋｄｏｎｅｗａｓｏｎｔｈｅｅｆｆｅｃｔｏｆｈｏｒｉｚｏｎｔａｌｃｕｒｒｅｎｔ.Ｆｅｗｏ ｃｅａｎｏｇｒａｐｈｅｒｓｈａｖｅｔａｋｅｎｎｏｔｅｏｆｔｈｅｉｎｆｌｕｅｎｃｅｏｆｖｅｒｔｉｃａｌｃｉｒｃｕｌａｔｉｏｎｏｎｔｈｅｓｕｓｐｅｎｄｅｄｍａｔｔｅ… 相似文献
12.
Hu Dunxin 《中国海洋湖沼学报》1984,2(1):12-19
It is found that the mud distributions in the Huanghai Sea and East China Sea are extremely identical with the upwelling's in terms of locality and extent. The process of the mud formation is examined. It is concluded that vertical circulation i.e. upwelling plays a determinant role in the process and furthermore, it is inferred that wherever upwelling occurs on continental shelf, mud should be formed and, conversely, wherever downwelling takes place, mud should not exist, for which coarse sediment should substitute. 相似文献
13.
14.
This research on the influence of sediment resuspension on the flux of materials in the margin of the East China Sea showed
that the sediment resuspension rates, was 47.40%–79.18% in the surface layers, and 72.75%–96.96% in the bottom layers. The
research confirmed that the Changjiang River runoff and the eddy area upwelling flow near 125°E were two important factors
affecting the sediment resuspension in summer; the transformation of DOC to POC through the flocculation in the transitional
region (123°–124°E) was also confirmed by comparison of the resuspension rate. The sediment resuspension was shown to be influenced
by the seasonal factor, especially in the surface layer.
Contribution No. 4017 from the Institute of Oceanology, Chinese Academy of Sciences.
Project 49636210 supported by NSFC. 相似文献
15.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅ“ｇｒｅｅｎｈｏｕｓｅｅｆｆｅｃｔ”ｒｅｓｕｌｔｉｎｇｆｒｏｍｔｈｅｉｎｃｒｅａｓｉｎｇｃａｒｂｏｎｄｉｏｘｉｄｅｉｎｔｈｅａｔｍｏｓｐｈｅｒｅｓｉｇｎｉｆｉ ｃａｎｔｌｙａｆｆｅｃｔｓｔｈｅｇｌｏｂａｌａｖｅｒａｇｅｔｅｍｐｅｒａｔｕｒｅ (Ｄｅｔｅｒ,1 978) ,ｈａｓｄｒａｗｎｔｈｅａｔｔｅｎｔｉｏｎｏｆｓｃｉｅｎｔｉｓｔｓａｒｏｕｎｄｔｈｅｗｏｒｌｄ .Ｓｃｉｅｎｔｉｓｔｓｃｏｎｓｉｄｅｒｔｈａｔｋｎｏｗｌｅｄｇｅｏｆｔｈｅｏｃｅａｎ’ｓｃａｐａｃｉｔｙｔｏａｂｓｏｒ… 相似文献
16.
1 INTRODUCTION The Yellow Sea is a shallow epicontinental sea surrounded by Chinese mainland and Korean Peninsula. It is connected with the East China Sea to the south, and with the Bohai Sea to the north- west. Water depth is generally less than 80 m with average of 44 m (Qin et al., 1989). The major sediment sources are the Huanghe and Changjiang (Yangtze) Rivers, providing annual sediment load of about 1.1×109 and 4.9×108 tons, respectively. A maximum of 1.6×108 tons of sedime… 相似文献
17.
Long chain alkyl diols have shown important potential for the reconstruction of sea surface temperature,productivities and upwelling conditions in marine or lacustrine environments.However,little is known about the distribution and sources of the diols in eastern China marginal seas(CMS),which are areas of important organic carbon sink.Here the contents of C_(30) and C_(32)1,15-diols were analyzed in 181 surface sediments from eastern CMS.The similar distribution pattern and strong linear correlation between C_(30) and C_(32) diols indicated that they had similar biological source,with a dominance of C_(30) diol.Their contents ranged from 7-2726 ng g~(-1) for C_(30) diol and 5-669 ng g~(-1) for C_(32) diol,and both showed higher values mainly in the mud area of the Yellow Sea,while the TOC normalized contents showed a more obvious seaward increasing trend.The similar distribution pattern and significant positive correlation between diols and the other marine biomarkers(brassicasterol,dinosterol,C_(37) alkenones) indicated C_(30) and C_(32) diols in eastern CMS were mainly from marine algae.This conclusion was also supported by principal component analysis(PCA).Our results also showed that sediment diol contents were generally related to marine productivity,suggesting that diols could be applied for marine productivity reconstruction in eastern CMS. 相似文献
18.
Numerical Study of Water and Suspended Matter Exchange Between the Yellow Sea and the East China Sea 总被引：3，自引：1，他引：2
INTRODUCTIONTheYellowSeaandtheEastChinaSea (ECS)aremarginalseasofthenorthwestPacificandhaveexpansivecontinentalshelves .TheuniqueandstrikingfeaturesoftheYellowSeaandtheECSarethattheyhavestrongtidalcurrent;aresubjecttostrongmonsooninfluence ;andreceiveinflowfromthebiggestriverinChina ,theChangjiangRiver ;andthatthefamouswesternboundarycurrent,theKuroshio ,passesthroughtheECS ,withitsbranchesintrudingupwardintothecontinentalshelfareas.Generallyspeaking ,thewaterexchangecapacityofthe… 相似文献
19.
Based on the field data obtained during cruises on the shelf of the East China Sea from 1997 to 1999, seasonal variations of coastal upwelling on the inner shelf are discussed by using cross-shelf transect profiles and horizontal distributions of chemical and hydrographic variables. Results show that the coastal upwelling was year-round, but the areas and intensities of the upwelling were quite different in season. The coastal upwelling occurred in all of the coastal areas of the region in spring and summer, but in autumn only in the area off Zhejiang Province, and in winter in the area off Fujian Prov- ince. It was the strongest in summer and the weakest in winter. Geographically, it was the strongest in the area off Zhejiang Province and the weakest in the southmost or northmost parts of the East China Sea. The estimated nutrient fluxes upward into euphotic zone through coastal upwelling were quite large, es- pecially for phosphate, which contributed significantly to primary production and improved the nutrient structure of the coastal ecosystem in the East China Sea. 相似文献