Modeling of marine litter drift and beaching in the Japan Sea     

Jong-Hwan Yoon  Shiro Kawano 《Marine pollution bulletin》2010,60(3):448-463

Characteristics of drift and beaching of floating marine litter in the Japan Sea are examined numerically using the reanalysis data of the Japan Sea Forecasting System of Kyushu University. The residence time of model marine litter deployed uniformly over the surface of the Japan Sea strongly depends on the buoyancy ratio. However, almost all litter beaches or flows out through straits within 3 years. Experiments with inputs of litter imposed at large cities and the Tsushima Straits as well as river basins of the Japan Sea exhibit a good agreement with beach surveys with regard to country ratios of beached litter along the Japanese coast in cases of lighters. In a case of lighter, almost all lighters originating from Japan beach along the Japanese coast, while almost all lighters originating from a country surrounding the Japan Sea except Japan beach along the coast of that country and the Japanese coast.  相似文献   

Millennium‐scale recurrent uplift inferred from beach deposits bordering the eastern Nankai Trough,Omaezaki area,central Japan     

Osamu Fujiwara  Kazuomi Hirakawa  Toshiaki Irizuki  Shiro Hasegawa  Yoshitaka Hase  Jun‐ichi Uchida  Kohei Abe 《Island Arc》2010,19(3):374-388

A flight of Holocene marine terraces on the southwestern coast of Cape Omaezaki of central Japan provides evidence of recurrent millennium‐scale uplift events. We reconstructed the uplift history of these terraces by using facies analysis of drill core and geoslicer samples, environmental analysis of trace fossils, and ¹⁴C age determinations. Coastal uplift can be identified by the displacement of beach deposits such as foreshore deposits, which represent the intertidal swash zone of a wave‐dominated sandy coast. Three levels of former beach deposits facing the Nankai Trough were identified near the coast in the Omaezaki area. The highest of these, dated at about 3020–2880 BC, records a maximum of 2.2–2.7 m of emergence. The middle beach surface, of minimum age 370–190 BC, shows 1.6–2.8 m of emergence. The lowest beach surface, which is older than 1300–1370 AD, records 0.4–1.6 m of emergence. Our analysis of vertical crustal deformation data during the Holocene in this region suggests that rapid and strong uplift was restricted to the southwestern coast of the Omaezaki area and was probably caused by high‐angle thrusting on subsidiary faults branching from the underlying plate boundary megathrust.  相似文献   

Variability of the metallic-line star 28 Andromedae     

Shiro Nishimura 《Astrophysics and Space Science》1969,3(1):77-79

The metallic-line A-type star 28 And was found to be variable both in brightness and radial velocity. The brightness in blue varies by 0^m.05, and the radial velocity by 5 km/sec with a period of 102 minutes. The minimum light occurs 0.12 P before the maximum radial velocity. The relation of 28 And to Scuti variables is briefly discussed.  相似文献   

Coping with pressures of modernization by traditional farmers: a strategy for sustainable rural development in Yunnan, China     

Chikamatsu Shiro  Jose Ireneu Furtad  Lixin Shen  Mei Yan 《山地科学学报》2007,4(1):057-070

Traditional farming practices conform to sustainable rural livelihoods, while agricultural modernisation tends to undermine these practices through various perturbations. A case study in Tengchong County (western Yunnan, China) shows that transformation of traditional alder (Alnus nepalensis) and dry rice (upland rice) rotational farming to introduced Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations leads to localised water scarcity and soil fertility decline. While farmers are aware of ecological sustainability of traditional farming, they prefer Chinese fir forestry because it is less labour-intensive, has a high market value, and releases time for profitable off-farm work. Farmers adapt to economic liberalization by planting high value crops and trees. However, alternatives to make local agricultural production more profitable through competitive business strategies, cooperative approaches, innovations in integrating high value crops and ‘downstream’ processing for sustainable rural livelihoods have been overlooked largely due to poor information availability and lack of organisational framework.  相似文献   

Correlating biostratigraphy and palaeoceanographic changes during late Quaternary at cold seeps with gas hydrate‐free areas of the Japan Sea using foraminifera paleoecology          下载免费PDF全文

Mahsa Saeidi Ortakand  Shiro Hasegawa  Ryo Matsumoto  Hiroki Matsuda 《Island Arc》2016,25(1):55-71

Late Quaternary foraminifera assemblages have been examined in two sediment cores (MD179‐3296 and MD179‐3317) from cold seep areas in the eastern margin of the Japan Sea, off Joetsu, Niigata Prefecture. Foraminifera assemblages in core MD179‐3296, which was located at the center of a pockmark on the Umitake Spur, show no evidence of methane flux and, especially in its upper portion, share the same paleo‐environmental history as other free gas hydrate areas of the Japan Sea. In comparison, in the core MD179‐3317 at the center of a pockmark at Joetsu Knoll, foraminiferal distributions were strongly affected by methane activities and, in the main part of the core, were deposited under local conditions. Three horizons were identified in this core, which are characterized by the high abundance value of Thalmannammina parkerae and might be related to methane flux due to sea level fall especially through late marine isotope stage (MIS) 3 and MIS 2.  相似文献   

Four-dimensional variational ocean reanalysis: a 30-year high-resolution dataset in the western North Pacific (FORA-WNP30)     

Norihisa Usui  Tsuyoshi Wakamatsu  Yusuke Tanaka  Nariaki Hirose  Takahiro Toyoda  Shiro Nishikawa  Yosuke Fujii  Yasushi Takatsuki  Hiromichi Igarashi  Haruka Nishikawa  Yoichi Ishikawa  Tsurane Kuragano  Masafumi Kamachi 《Journal of Oceanography》2017,73(2):205-233

We produced a four-dimensional variational ocean re-analysis for the Western North Pacific over 30 years (FORA-WNP30). It is the first-ever dataset covering the western North Pacific over 3 decades at eddy-resolving resolution. The four-dimensional variational analysis scheme version of the Meteorological Research Institute Multivariate Ocean Variational Estimation system (MOVE-4DVAR) is employed to conduct a long-term reanalysis experiment during 1982–2012. After evaluating the basic performance of FORA-WNP30, the interannual to decadal variability is analyzed. Overall, FORA-WNP30 reproduces basic features in the western North Pacific well. One of outstanding features in FORA-WNP30 is that anomalous events such as the Kuroshio large meander and anomalous intrusion of the Oyashio in the 1980s, when there were no altimeter data, are successfully reproduced. FORA-WNP30 is therefore a valuable dataset for a variety of oceanographic research topics and potentially for related fields such as climate study, meteorology and fisheries.  相似文献   

DATABASE ON INTERNET FOR GEOLOGICAL SURVEY OF JAPAN GEOCHEMICAL REFERENCE SAMPLES     

Noboru IMAI  Hiroshi SAKURAMACHI  Shigeru TERASHIMA  Shiro ITOH  Atsushi ANDO 《Geostandards and Geoanalytical Research》1996,20(2):161-164

A database on thirty-one Geological Survey of Japan (GSJ) geochemical reference samples has been set up on Internet which allows the retrieval of recommended or preferable values, compiled data, location, sample preparation and other relevant information. The URL location on WWW server is: http://www.aist.go.jp./RIODB/geostand/welcome.html  相似文献   

A new proposal for simplified design of buried steel pipes crossing active faults     

Shiro Takada  Nemat Hassani  Katsumi Fukuda 《地震工程与结构动力学》2001,30(8):1243-1257

Simplified design methods for obtaining the maximum strain in pipelines crossing active faults proposed by Newmark, Kennedy and Wang have not considered the section deformation of the pipe. In this study, a new simplified method is developed for obtaining the maximum strain in steel pipes crossing faults considering non‐linearity of material and geometry of pipe section. It is assumed that the pipe will bend near the fault and the geometry of pipe in the longitudinal direction will change according to a bent deformation. On the other hand, the relation between maximum strain and bent angle has been obtained using a beam–shell hybrid FEM for different pipe‐fault conditions. The developed method can be used for calculating the maximum strains for fault‐crossing steel pipes with different angles of crossing both in tension and compression, by considering the deformation of the pipe cross‐section. Copyright © 2001 John Wiley Sons, Ltd.  相似文献   

GOLD IN TWENTY-SIX JAPANESE GEOCHEMICAL REFERENCE SAMPLES     

Shigeru TERASHIMA  Shiro ITOH  Atsushi ANDO 《Geostandards and Geoanalytical Research》1992,16(1):9-10

Gold has been determined in 26 geochemical reference samples with graphite furnace AAS after digesting the samples with aqua regia and hydrofluoric acid and extracting gold by methyl isobutyl ketone (MIBK). This method yields clearly higher values than those by the partial attack using aqua regia digestion.  相似文献   

An equivalent-boundary method for the shell analysis of buried pipelines under fault movement     

Liu Ai-wen  Hu Yu-xian  Zhao Feng-xin  Li Xiao-jun  Takada Shiro  Zhao Lei 《地震学报(英文版)》2004,17(1):150-156

A new shell finite element method (FEM) model with an equivalent boundary is presented for estimating the response of a buried pipeline under large fault movement. The length of affected pipeline under fault movement is usually too long for a shell-mode calculation because of the limitation of memory and time of computers. In this study, only the pipeline segment near fault is modeled with plastic shell elements to study the local buckling and the large section deformation in pipe. The material property of pipe segment far away from the fault is considered as elastic, and nonlinear spring elements at equivalent boundaries are obtained and applied to two ends of shell model. Compared with the fixed-boundary shell model, the shell model with an equivalent boundary proposed by the study can remarkably reduce the needed memory and calculating time. Foundation item: National Natural Sciences Foundation of China (50078049). Contribution No. 04FE1017, Institute of Geophysics, China Earthquake Administration.  相似文献