Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised...Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4–8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Pliocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.展开更多
A dedicated 24 h S/X dual-band geodetic very long baseline interferometry(VLBI) experiment was conducted in January 2015 with the goal of improving the position estimates for the Chinese Deep Space Station Kashi. Prev...A dedicated 24 h S/X dual-band geodetic very long baseline interferometry(VLBI) experiment was conducted in January 2015 with the goal of improving the position estimates for the Chinese Deep Space Station Kashi. Previously, the position estimates had been only accurate to ~20 cm, which is insufficient for future Chinese deep space explorations. The experiment design and data reduction are described with special emphasis on the limited frequency ranges of Kashi for bandwidth synthesis. A narrowed multi-band delay search window based on post-fit residuals was utilized to resolve the sub-ambiguities due to the drop of a frequency channel in fringe fit, which saved ~22% of the observations from the affected baseline. Final position estimates of Kashi were obtained from the global solution by using more than 5300 international VLBI sessions from August 1979 to September 2015, and estimates were found to be accurate to about 10, 25, and 20 mm in the X, Y, and Z components. Various statistical tests were run, and the estimates and precisions are believed to be reliable.展开更多
基金Supported by the National High Technology Research and Development Program of China (863 Program, 2006AA09Z349)the National Basic Research Program of China (2007CB411703)
文摘Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4–8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Pliocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.
基金supported by China’s Lunar Exploration Key Techniques Research Program (Grant No. TY3Q20100009)
文摘A dedicated 24 h S/X dual-band geodetic very long baseline interferometry(VLBI) experiment was conducted in January 2015 with the goal of improving the position estimates for the Chinese Deep Space Station Kashi. Previously, the position estimates had been only accurate to ~20 cm, which is insufficient for future Chinese deep space explorations. The experiment design and data reduction are described with special emphasis on the limited frequency ranges of Kashi for bandwidth synthesis. A narrowed multi-band delay search window based on post-fit residuals was utilized to resolve the sub-ambiguities due to the drop of a frequency channel in fringe fit, which saved ~22% of the observations from the affected baseline. Final position estimates of Kashi were obtained from the global solution by using more than 5300 international VLBI sessions from August 1979 to September 2015, and estimates were found to be accurate to about 10, 25, and 20 mm in the X, Y, and Z components. Various statistical tests were run, and the estimates and precisions are believed to be reliable.
