To clarify temporal changes in the transboundary pollution, we analyzed SCPs （spheroidal carbonaceous particles） in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of an...To clarify temporal changes in the transboundary pollution, we analyzed SCPs （spheroidal carbonaceous particles） in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of anthropogenic atmospheric pollution in bottom sediments. Recently deposited SCPs in air and unmelted snow on Mt. Fuji were also characterized. The concentrarion and characteristics of SCPs reflected the environmental and industrial history of the area. Evidence of transboundary air pollution was observed after the 1980s in Yashagaike and Kotaniike ponds in Japan, which are located on the coast of the Sea of Japan. The concentration suggests that the pollutants originated from continental Asia, particularly after the 1980s. The chemical composition of the SCPs allowed the source of emissions to be identified. Chinese SCPs were found at Yashagaike and Kotaniike ponds in Japan, and at Songiiho and Urimji lakes in Korea. The size distributions showed that small SCPs are transported over long distances. On the summit of Mr. Fuji, SCPs transported by the prevailing westerlies from China were found in addition to SCPs emitted in Japan.展开更多
Prestack depth migration for seismic reflection data is commonly used tool for imaging complex geological structures such as salt domes, faults, thrust belts, and stratigraphic structures. Phase shift plus interpolati...Prestack depth migration for seismic reflection data is commonly used tool for imaging complex geological structures such as salt domes, faults, thrust belts, and stratigraphic structures. Phase shift plus interpolation (PSPI) algorithm is a useful tool to directly solve a wave equation and the results have natural properties of the wave equation. Amplitude and phase characteristics, in particular, are better preserved. The PSPI algorithm is widely used in hydrocarbon exploration because of its simplicity, efficiency, and reduced efforts for computation. However, meaningful depth image of 3D subsurface requires parallel computing to handle heavy computing time and great amount of input data. We implemented a parallelized version of 3D PSPI for prestack depth migration using Open-Multi-Processing (Open MP) library. We verified its performance through applications to 3D SEG/EAGE salt model with a small scale Linux cluster. Phase-shift was performed in the vertical and horizontal directions, respectively, and then interpolated at each node. This gave a single image gather according to shot gather. After summation of each single image gather, we got a 3D stacked image in the depth domain. The numerical model example shows good agree- ment with the original geological model.展开更多
文摘To clarify temporal changes in the transboundary pollution, we analyzed SCPs （spheroidal carbonaceous particles） in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of anthropogenic atmospheric pollution in bottom sediments. Recently deposited SCPs in air and unmelted snow on Mt. Fuji were also characterized. The concentrarion and characteristics of SCPs reflected the environmental and industrial history of the area. Evidence of transboundary air pollution was observed after the 1980s in Yashagaike and Kotaniike ponds in Japan, which are located on the coast of the Sea of Japan. The concentration suggests that the pollutants originated from continental Asia, particularly after the 1980s. The chemical composition of the SCPs allowed the source of emissions to be identified. Chinese SCPs were found at Yashagaike and Kotaniike ponds in Japan, and at Songiiho and Urimji lakes in Korea. The size distributions showed that small SCPs are transported over long distances. On the summit of Mr. Fuji, SCPs transported by the prevailing westerlies from China were found in addition to SCPs emitted in Japan.
文摘Prestack depth migration for seismic reflection data is commonly used tool for imaging complex geological structures such as salt domes, faults, thrust belts, and stratigraphic structures. Phase shift plus interpolation (PSPI) algorithm is a useful tool to directly solve a wave equation and the results have natural properties of the wave equation. Amplitude and phase characteristics, in particular, are better preserved. The PSPI algorithm is widely used in hydrocarbon exploration because of its simplicity, efficiency, and reduced efforts for computation. However, meaningful depth image of 3D subsurface requires parallel computing to handle heavy computing time and great amount of input data. We implemented a parallelized version of 3D PSPI for prestack depth migration using Open-Multi-Processing (Open MP) library. We verified its performance through applications to 3D SEG/EAGE salt model with a small scale Linux cluster. Phase-shift was performed in the vertical and horizontal directions, respectively, and then interpolated at each node. This gave a single image gather according to shot gather. After summation of each single image gather, we got a 3D stacked image in the depth domain. The numerical model example shows good agree- ment with the original geological model.
