Sharples’ 1 D physical model employing tide wind driven turbulence closure and surface heating cooling physics, was coupled with an ecological model with 9 biochemical components: phytoplankton, zooplankton, shellfis...Sharples’ 1 D physical model employing tide wind driven turbulence closure and surface heating cooling physics, was coupled with an ecological model with 9 biochemical components: phytoplankton, zooplankton, shellfish, autotrophic and heterotrophic bacterioplankton, dissolved organic carbon (DOC), suspended detritus and sinking particles to simulate the annual evolution of ecosystem in the central part of Jiaozhou Bay. The coupled modeling results showed that the phytoplankton shading effect could reduce seawater temperature by 2℃, so that photosynthesis efficiency should be less than 8%; that the loss of phytoplankton by zooplankton grazing in winter tended to be compensated by phytoplankton advection and diffusion from the outside of the Bay; that the incident irradiance intensity could be the most important factor for phytoplankton growth rate; and that it was the bacterial secondary production that maintained the maximum zooplankton biomass in winter usually observed in the 1990s, indicating that the microbial food loop was extremely important for ecosystem study of Jiaozhou Bay.展开更多
The continental slope of the Taiwan Shoal, which has cultivated numerous submarine canyons, is located in a passive conti- nental margin environment. However, the trend of the Taiwan Canyon, with its 45° intersec...The continental slope of the Taiwan Shoal, which has cultivated numerous submarine canyons, is located in a passive conti- nental margin environment. However, the trend of the Taiwan Canyon, with its 45° intersection angle, is obviously different from that of the erosion valley downward along the continental slope. A distinct break is present in the lower segment of the Taiwan Canyon, which then extends from west to east parallel to the continental slope until finally joining the Manila Trench. By utilizing multiple-beam water depth data, high-resolution seismic data, and sediment cores, this study describes the topo- graphic characteristics of the Taiwan Canyon and provides a preliminary discussion on the origin of the Taiwan Canyon and its effect on deepwater sediment. The terrain, landform, and sediment of the Taiwan Canyon exhibit segmentation characteristics. The upper segment is characterized primarily by erosion, downward cutting with a V shape, and wide development of sliding, slumping, and other gravity flow types. The middle segment is characterized mostly by U-shaped erosion-sedimentation transi- tion and development of an inner levee. The lower segment is characterized primarily by sedimentation and development of a sediment wave. The bottom current has a significant reworking effect on the interior sediments of the canyon and forms re- worked sands. The formation and evolution of the Taiwan Canyon is closely related to sediment supply, gravity sliding （slumping）, faulting activities, and submarine impaling. Given the sufficient terrigenous clastic supply, the sediments along the continental shelf edge continuously proceed seaward; gliding and slumping in the front edge provide driving forces for the formation of the canyon. Faulting activities result in stratum crushing, and the gravity flow takes priority in eroding the relatively fragile stratum. Thus, the direction of the extension of the canyon crosses the surrounding erosion valley obliquely. Seamounts are formed through submarine impaling. Owing to seamount blocking, the lower segment of the canyon is turned toward the east-west direction. Large amounts of sediments overflow at the turning, formin~ sediment waves.展开更多
文摘Sharples’ 1 D physical model employing tide wind driven turbulence closure and surface heating cooling physics, was coupled with an ecological model with 9 biochemical components: phytoplankton, zooplankton, shellfish, autotrophic and heterotrophic bacterioplankton, dissolved organic carbon (DOC), suspended detritus and sinking particles to simulate the annual evolution of ecosystem in the central part of Jiaozhou Bay. The coupled modeling results showed that the phytoplankton shading effect could reduce seawater temperature by 2℃, so that photosynthesis efficiency should be less than 8%; that the loss of phytoplankton by zooplankton grazing in winter tended to be compensated by phytoplankton advection and diffusion from the outside of the Bay; that the incident irradiance intensity could be the most important factor for phytoplankton growth rate; and that it was the bacterial secondary production that maintained the maximum zooplankton biomass in winter usually observed in the 1990s, indicating that the microbial food loop was extremely important for ecosystem study of Jiaozhou Bay.
基金supported by National Natural Science Foundation of China(Grant Nos.41372115,40972077)
文摘The continental slope of the Taiwan Shoal, which has cultivated numerous submarine canyons, is located in a passive conti- nental margin environment. However, the trend of the Taiwan Canyon, with its 45° intersection angle, is obviously different from that of the erosion valley downward along the continental slope. A distinct break is present in the lower segment of the Taiwan Canyon, which then extends from west to east parallel to the continental slope until finally joining the Manila Trench. By utilizing multiple-beam water depth data, high-resolution seismic data, and sediment cores, this study describes the topo- graphic characteristics of the Taiwan Canyon and provides a preliminary discussion on the origin of the Taiwan Canyon and its effect on deepwater sediment. The terrain, landform, and sediment of the Taiwan Canyon exhibit segmentation characteristics. The upper segment is characterized primarily by erosion, downward cutting with a V shape, and wide development of sliding, slumping, and other gravity flow types. The middle segment is characterized mostly by U-shaped erosion-sedimentation transi- tion and development of an inner levee. The lower segment is characterized primarily by sedimentation and development of a sediment wave. The bottom current has a significant reworking effect on the interior sediments of the canyon and forms re- worked sands. The formation and evolution of the Taiwan Canyon is closely related to sediment supply, gravity sliding （slumping）, faulting activities, and submarine impaling. Given the sufficient terrigenous clastic supply, the sediments along the continental shelf edge continuously proceed seaward; gliding and slumping in the front edge provide driving forces for the formation of the canyon. Faulting activities result in stratum crushing, and the gravity flow takes priority in eroding the relatively fragile stratum. Thus, the direction of the extension of the canyon crosses the surrounding erosion valley obliquely. Seamounts are formed through submarine impaling. Owing to seamount blocking, the lower segment of the canyon is turned toward the east-west direction. Large amounts of sediments overflow at the turning, formin~ sediment waves.
