1996 Vol. 15, No. 4
Display Method:
1996, (4): 423-435.
Abstract:
A modified inverse method is used to compute the circulations east of Taiwan and in the East China Sea and east of the Ryūkyū Islands with hydrographic data obtained during early summer of 1985. The computational region covers an area west of 129°E and from 21°45'N to 35°N.
A modified inverse method is used to compute the circulations east of Taiwan and in the East China Sea and east of the Ryūkyū Islands with hydrographic data obtained during early summer of 1985. The computational region covers an area west of 129°E and from 21°45'N to 35°N.
1996, (4): 437-445.
Abstract:
Based on the remote sensing information and related condition such as geology, geomorphology, hydrology and meteorology, a remote sensing expert system of the South China Sea coral reefs is developed by using a new remote sensing twin-tree structure. The object is recognized and the type of coral reef is distinguished through the combined utilization of spectrum and image primitive's spatial relation and related information.
Based on the remote sensing information and related condition such as geology, geomorphology, hydrology and meteorology, a remote sensing expert system of the South China Sea coral reefs is developed by using a new remote sensing twin-tree structure. The object is recognized and the type of coral reef is distinguished through the combined utilization of spectrum and image primitive's spatial relation and related information.
1996, (4): 447-455.
Abstract:
The CO2 exchange between atmosphere and seawater has been discussed. The physical process of exchange at seasurface is related closely with the atmospheric forcing. The result of a dynamics analysis of the CO2 flux actvas the seasurface, and a computed example over the shelf area of the East China See are reported. The analysis and calculation show that the CO2 vertical flux at seawater is mainly dependent on the CO2 concentration difference between seawater and atmosphere. Its exchange velocity is affected by the friction velocity, solubility and resistivity. The agreement between this exchange velocity and recent wind tunnel experimental results is good with wind speed over the range 4-10 m/s. This flux can increase very fast with the increase of wind speed, but very small with the increase of temperature. During the three cruise expeditions in October 1993, and April and October 1994, the CO2 vertical flux at eeasurface was directed downward over the shelf area of the East China Sea. Because the CO2 partial pressure difference between seawater and atmosphere was a negative value, the flux value was -45.5 μg/(m2·h) in average.
The CO2 exchange between atmosphere and seawater has been discussed. The physical process of exchange at seasurface is related closely with the atmospheric forcing. The result of a dynamics analysis of the CO2 flux actvas the seasurface, and a computed example over the shelf area of the East China See are reported. The analysis and calculation show that the CO2 vertical flux at seawater is mainly dependent on the CO2 concentration difference between seawater and atmosphere. Its exchange velocity is affected by the friction velocity, solubility and resistivity. The agreement between this exchange velocity and recent wind tunnel experimental results is good with wind speed over the range 4-10 m/s. This flux can increase very fast with the increase of wind speed, but very small with the increase of temperature. During the three cruise expeditions in October 1993, and April and October 1994, the CO2 vertical flux at eeasurface was directed downward over the shelf area of the East China Sea. Because the CO2 partial pressure difference between seawater and atmosphere was a negative value, the flux value was -45.5 μg/(m2·h) in average.
1996, (4): 457-468.
Abstract:
The analysis on the magnetic fabric of profile of the sedimentary core taken in five stations in the small spreading ridge area in Mariana Trough shows that the effect of indicating its depositional fabric, sedimentary rhythm, sedimentary events, sedimentary interfaces and sediment composition as well as sedimentary dynamic environment by magnetic parameters is clearer than that by traditional method of analysis. The indication of sedimentary events show its high resolution. The study on the Late Quaternary sedimentary events in this area shows that this area underwent four big events of sudden change in the Holocene epoch, based on the sudden change of underflow direction and the position relationship between ash beds and erosion sediment layers. The sudden change of underflow direction is a believable evidence for judgement and study of sudden event within this area. The direction changes of its geomagnetic field show three morphotypes i.e. relatively stable type and non-stable type of oscillatory amplitude of magnetic inclination (Inc) which existed during the relatively stable period of amplitude of magnetic declination (Inc).Another type is characterized by big amplitude of both inclination and declination.The space-time series of the three types mentioned above is a new way for forming a high-resolution stratigraphical timetable.
The analysis on the magnetic fabric of profile of the sedimentary core taken in five stations in the small spreading ridge area in Mariana Trough shows that the effect of indicating its depositional fabric, sedimentary rhythm, sedimentary events, sedimentary interfaces and sediment composition as well as sedimentary dynamic environment by magnetic parameters is clearer than that by traditional method of analysis. The indication of sedimentary events show its high resolution. The study on the Late Quaternary sedimentary events in this area shows that this area underwent four big events of sudden change in the Holocene epoch, based on the sudden change of underflow direction and the position relationship between ash beds and erosion sediment layers. The sudden change of underflow direction is a believable evidence for judgement and study of sudden event within this area. The direction changes of its geomagnetic field show three morphotypes i.e. relatively stable type and non-stable type of oscillatory amplitude of magnetic inclination (Inc) which existed during the relatively stable period of amplitude of magnetic declination (Inc).Another type is characterized by big amplitude of both inclination and declination.The space-time series of the three types mentioned above is a new way for forming a high-resolution stratigraphical timetable.
1996, (4): 469-492.
Abstract:
Microtextures and structures of 9 hydrothermal chimneys sampled on the small spreading ridge of the Mariana Trough during SONNE Cruise 57 (5057) and 69 (5069) in 1988 and 1990 were studied by means of scanning electron microscope. The results reveal that the two types of chimneys from the Mariana Trough, the 0silicic chimneys" containing Fe sulfide and the pure "silica chimneys" without sulfide, vary distinctly not only in mineral and chemical compositions, but also in microtextures and structures. The silicic chimneys generally show three major types of microtextures. The inside of the chimneys is dominated by holocrystalline or semicrystalline idiomorphic and hypidiomorphic granular textures and the outwall by amorphous colloidal texture. In some of the silicic chimneys relict texture is observed. However, the pure silica chimneys show chiefly amorphous colloidal texture from the inside to the outwall. Microstructurally, the inside of the silicic chimneys is dominated by a "silica-covering" structure and a "voidfilling" structure, and the outwall by a chain-like or three-dimentional chain-network structure built up by individual opal globules, whereas the pure silica chimneys are mainly three-dimentiottal chain-network and the dense silica bands in structure. These variations suggest that not only mineralizing conditions but also processes differ distinctly during the formation of the two types of chimneys, and that hydrothermal mineralization in the Mariana Trough shows a multistage or multieplsodical nature.
Microtextures and structures of 9 hydrothermal chimneys sampled on the small spreading ridge of the Mariana Trough during SONNE Cruise 57 (5057) and 69 (5069) in 1988 and 1990 were studied by means of scanning electron microscope. The results reveal that the two types of chimneys from the Mariana Trough, the 0silicic chimneys" containing Fe sulfide and the pure "silica chimneys" without sulfide, vary distinctly not only in mineral and chemical compositions, but also in microtextures and structures. The silicic chimneys generally show three major types of microtextures. The inside of the chimneys is dominated by holocrystalline or semicrystalline idiomorphic and hypidiomorphic granular textures and the outwall by amorphous colloidal texture. In some of the silicic chimneys relict texture is observed. However, the pure silica chimneys show chiefly amorphous colloidal texture from the inside to the outwall. Microstructurally, the inside of the silicic chimneys is dominated by a "silica-covering" structure and a "voidfilling" structure, and the outwall by a chain-like or three-dimentional chain-network structure built up by individual opal globules, whereas the pure silica chimneys are mainly three-dimentiottal chain-network and the dense silica bands in structure. These variations suggest that not only mineralizing conditions but also processes differ distinctly during the formation of the two types of chimneys, and that hydrothermal mineralization in the Mariana Trough shows a multistage or multieplsodical nature.
1996, (4): 493-513.
Abstract:
The section of Yujiawaizi Loess in Dalian, one of the typical sections of China's coastal loess, revealed three reliable polarity reversal events, i.e.,Mungo Event (27.5-23.7 ka BP), Laschamp Event (43.5-37.3 ka BP) and Blake Event (125. 4-110.5 ka BP);while reliability of the fourth one, Gothenburg Event, retrains to be confirmed. Based on TL datings, polarity events and magnetic susceptibility, the authors have tentatively established the time series of coastal loess accumulation since 140 000 a BP, and estimated the accumulation rate of Lt. Meanwhile, the high-resolution magnetic susceptibility curve since 140 000 a BP can be correlated with that of the inland loess in northwest China and δ 18O curves of polar ice core and deep sea cores, but there are still some differences, representing the particular characteristics of coastal environmental evolution. At last, integrating the polarity strata, magnetic susceptibility and other relative data, the authors have probed into the paleoenvironmental changes since 140 ka BP and climate oscillation cycle of different scale, polarity events and glacial-postglacial climate transition, differences in climate and environment between the early and late stages of last glacial period, and the continuance of coastal loess accumulation.
The section of Yujiawaizi Loess in Dalian, one of the typical sections of China's coastal loess, revealed three reliable polarity reversal events, i.e.,Mungo Event (27.5-23.7 ka BP), Laschamp Event (43.5-37.3 ka BP) and Blake Event (125. 4-110.5 ka BP);while reliability of the fourth one, Gothenburg Event, retrains to be confirmed. Based on TL datings, polarity events and magnetic susceptibility, the authors have tentatively established the time series of coastal loess accumulation since 140 000 a BP, and estimated the accumulation rate of Lt. Meanwhile, the high-resolution magnetic susceptibility curve since 140 000 a BP can be correlated with that of the inland loess in northwest China and δ 18O curves of polar ice core and deep sea cores, but there are still some differences, representing the particular characteristics of coastal environmental evolution. At last, integrating the polarity strata, magnetic susceptibility and other relative data, the authors have probed into the paleoenvironmental changes since 140 ka BP and climate oscillation cycle of different scale, polarity events and glacial-postglacial climate transition, differences in climate and environment between the early and late stages of last glacial period, and the continuance of coastal loess accumulation.
1996, (4): 515-527.
Abstract:
This paper deals with, comprehensively, for the first time, the species composition, number and its distributional characteristics of polychaetes in the soft bottom in the west of the Taiwan Stnut. This paper is sorted out on the basis of the data from the polychaete samples collected with quantitative benthic grab and quantitative trawl in the biological seasons in four cruises including 220 stations from 1984 to 1985. The survey areas were located from the Minjiang Estuary in the north to the south of the Taiwan Shoal in the south (22°23. 1'-25°43.0'N, 116°30.8'-120° 30.7'E).The survey stations are shown in Fig.1.
This paper deals with, comprehensively, for the first time, the species composition, number and its distributional characteristics of polychaetes in the soft bottom in the west of the Taiwan Stnut. This paper is sorted out on the basis of the data from the polychaete samples collected with quantitative benthic grab and quantitative trawl in the biological seasons in four cruises including 220 stations from 1984 to 1985. The survey areas were located from the Minjiang Estuary in the north to the south of the Taiwan Shoal in the south (22°23. 1'-25°43.0'N, 116°30.8'-120° 30.7'E).The survey stations are shown in Fig.1.
1996, (4): 529-538.
Abstract:
By air-dry method, the karyotype from gill cell in three clams of Bivalvia Pterimorphia Arcidae,Tegillarca granosa, Scapharca subcrenata and S. broughtonii. Was studied. Their chromosome number(2n) and fundamental number (NF) are equal to each other. But their karyotype is different. In T. grunasa. it is 2n=38, 28m+10sm; In S. subcrenata 2n=38, 14m+22sm+2st. In S. broughtonii 2n=38, 12m+20sm+6st. T.granosa has no subtelocentric (st) chromosome. S. subcrenata has one pair and S. broughtonii has three paris of st. Middle centric (m) and submiddle centric chromosome are major type in karyotype of three species of Arcida; the lengths of chtotnosomes from the largest to the smallest changed gradually. The absolute length of the maximum chromosome in all three species do not exceed 5 μm and the minimum chromosome is about 2 μm. Inversion pericentric perhaps plays an important role in the evolution of chromosome. Hybridization among the three species of Arcidae is possible.
By air-dry method, the karyotype from gill cell in three clams of Bivalvia Pterimorphia Arcidae,Tegillarca granosa, Scapharca subcrenata and S. broughtonii. Was studied. Their chromosome number(2n) and fundamental number (NF) are equal to each other. But their karyotype is different. In T. grunasa. it is 2n=38, 28m+10sm; In S. subcrenata 2n=38, 14m+22sm+2st. In S. broughtonii 2n=38, 12m+20sm+6st. T.granosa has no subtelocentric (st) chromosome. S. subcrenata has one pair and S. broughtonii has three paris of st. Middle centric (m) and submiddle centric chromosome are major type in karyotype of three species of Arcida; the lengths of chtotnosomes from the largest to the smallest changed gradually. The absolute length of the maximum chromosome in all three species do not exceed 5 μm and the minimum chromosome is about 2 μm. Inversion pericentric perhaps plays an important role in the evolution of chromosome. Hybridization among the three species of Arcidae is possible.
1996, (4): 539-556.
Abstract:
