Inaugural Address 25:1          下载免费PDF全文

Tetsuji Muto  Yoshihiko Tamura 《Island Arc》2016,25(1):3-3

  相似文献   

e–log σv′ relationship for marine clays considering initial water content to evaluate soil structure     

Takashi Tsuchida 《Marine Georesources & Geotechnology》2017,35(1):104-119

  相似文献   

Preliminary results of the Japan-Taiwan joint survey on combining ocean radar data in the Kuroshio upstream region     

Kaoru Ichikawa  Wen Chang Yang  Akihiko Morimoto  Yutaka Yoshikawa  Shigeo Sugitani  Wen-Shan Chiang  Jian-Wu Lai  En Yu Liang  Cho-Teng Liu  Chang-Wei Lee  Kei Yufu  Moeto Kyushima  Satoshi Fujii  Tomoharu Senju  Yoshihiko Ide 《Ocean Science Journal》2013,48(1):141-148

  相似文献   

Surface lowering rates of uplifted limestone terraces estimated from the height of pedestals on a subtropical island of Japan     

Yukinori Matsukura  Akira Maekado  Hisashi Aoki  Tetsuya Kogure  Yoshihiko Kitano 《地球表面变化过程与地形》2007,32(7):1110-1115

In Kikai‐jima, south‐western Japan, many pedestal rocks have developed on the surface of Holocene raised coral‐reef terraces with known dates of emergence. Pedestals are formed just under boulders, which are considered to have been transported by tsunami and settled on a reef flat before emergence. On the assumption that boulders protect the underlying limestone terrace from rainfall solution, the rate of surface lowering of these limestone terraces was evaluated from the height of pedestals and the period of their formation. The result showed that the mean lowering rate over 6000 years is 205 mm/ky. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Ecological aspects of hydrothermal vent animals in captivity at atmospheric pressure     

Hiroshi Miyake  Mitsugu Kitada  Shinji Tsuchida  Yoko Okuyama  & Ko-ichi Nakamura 《Marine Ecology》2007,28(1):86-92

Hydrothermal vent animals were kept and displayed at atmospheric pressure with an artificial hydrothermal vent system in Enoshima Aquarium, Fujisawa, Kanagawa, Japan. The artificial hydrothermal vent system was composed of a main rearing tank, a heating tank, a hot water outlet with added Na₂S as the source of H₂S, and added CO₂ for chemosynthetic bacteria and pH regulation. When the need arises, a dissolved oxygen control unit and submersible heaters can be attached. We are now rearing hydrothermal vent crabs (Austinograea yunohana), hydrothermal vent galatheid crabs (Shinkaia crosnieri), vestimentiferan tubeworms (Lamellibrachia satsuma), hydrothermal vent shrimp (Opaepele spp.), hydrothermal vent barnacles (Ashinkailepas seepiophilia and Neoverruca sp.), and tonguefish (Symphurus sp.). In the artificial hydrothermal vent tank, shrimp and crabs have been observed to cluster close to the artificial hydrothermal vent. In particular, large (adult) crabs needed a heat source to live in the aquarium over a long term. Additionally, some species (A. yunohana, S. crosnieri, Opaepele sp. and Symphurus sp.) have spawned and hatched in captivity. It is likely higher water temperatures are needed for egg and larval development compared with temperatures for adult requirements.  相似文献   

Topographic effect of a marine ridge on the spin-down of a cyclonic eddy     

Yoshihiko Sekine 《Journal of Oceanography》1989,45(3):190-203

The topographic effect of a meridional marine ridge on the spin-down of a cyclonic eddy is discussed by use of a two layer model. It is shown that cyclonic eddies on the eastern side of a marine ridge decay in a shorter time in comparison with those on the western side. The fast decay on the eastern side is mainly due to the planetary effect, which carries the eddy westward to a shallower region on the ridge, where remarkable frictional spin-down is carried out. Conversely, westward shift of the similar cyclonic eddy yields a weak bottom effect in the western side. It is inferred that the resulting remarkable spin-down on the eastern side of a marine ridge is one of the causes of the observed fast decay of the cyclonic cold water mass accompanied by the large meander of the Kuroshio on the eastern side of the Izu Ridge south of Japan.  相似文献   

A numerical study on the generation of the small meander of the Kuroshio off southern Kyûshû     

Yoshihiko Sekine  Yoshiaki Toba 《Journal of Oceanography》1981,37(5):234-242

The generation of small meanders of the Kuroshio off southern Kyûshû is investigated. Basing on the fact that the small meanders tend to follow an increase in velocity of the Kuroshio in the Satsunan region (Sekine andToba, 1981), the influence of this velocity increase on the quasi-stationary path of the Kuroshio is studied numerically. Simplified bottom and coastal topographies are employed in a two layer model ocean. A quasi-stationary numerical solution with a constant inflow is used for the initial condition, and a temporal increase in the inflow with corresponding leakage is employed as the boundary condition to investigate nonlinear effects due to the increase in current velocity. Experiments for four different physical models are carried out to determine the specific roles of the continental slope, the planetary-effect, and density stratification. Temporal increase in the inflow tends to cause offshore shift of the current path. But the topographic effect of the continental slope is strong enough that no significant shift of the current path occurs in the case of the barotropic ocean. However, in the case of a baroclinic ocean, temporal increase in the inflow does cause generation of small meanders, because density stratification diminishes the topographic effect. A larger density stratification provides more favorable condition for the appearance of the small meander, and a cyclonic eddy is formed on the continental side of the small meander path.  相似文献   

The Zealandia Volcanic Complex: Further evidence of a lower crustal “hot zone” beneath the Mariana Intra‐oceanic Arc,Western Pacific     

Robert J. Stern  Yoshihiko Tamura  Hiroshi Shukuno  Takashi Miyazaki 《Island Arc》2019,28(5)

This paper addresses formation of felsic magmas in an intra‐oceanic magmatic arc. New bathymetric, petrologic, geochemical, and isotopic data for Zealandia Bank and two related volcanoes in the south‐central Mariana arc is presented and interpreted. These three volcanoes are remnants of an older andesitic volcano that evolved for some time and became dormant long enough for a carbonate platform to grow on its summit before reawakening as a rhyodacitic volcano. Zealandia lavas are transitional between low‐ and medium‐K and tholeiitic and calc‐alkaline suites. They define a bimodal suite with a gap of 56–58 wt% SiO₂; this suggests that mafic and felsic magmas have different origins. The magmatic system is powered by mantle‐derived basalts having low Zr/Y and flat rare earth element patterns. Two‐pyroxene thermometry yields equilibration temperatures of 1000–1100 °C for andesites and 900–1000 °C for dacites. Porphyritic basalts and andesites show textures expected for fractionating magmas but mostly fine‐grained felsic lavas do not. All lavas show trace element signatures expected for mantle and crustal sources that were strongly melt‐depleted and enriched by subduction‐related fluids and sediment melts. Sr and Nd isotopic compositions fall in the normal range of Mariana arc lavas. Felsic lavas show petrographic evidence of mixing with mafic magma. Zealandia Bank felsic magmatism supports the idea that a large mid‐ to lower‐crustal felsic magma body exists beneath the south‐central Mariana arc, indicating that MASH (mixing, assimilation, storage, and homogenization) zones can form beneath intra‐oceanic as well as continental arcs.  相似文献   

A Subaru/Suprime-Cam wide-field survey of globular cluster populations around M87 – I. Observation, data analysis and luminosity function     

Naoyuki Tamura †  Ray M. Sharples  Nobuo Arimoto  Masato Onodera  Kouji Ohta  Yoshihiko Yamada 《Monthly notices of the Royal Astronomical Society》2006,373(2):588-600

  相似文献   

Analyses of age and population genetic structure of the broadbanded thornyhead Sebastolobus macrochir in North Japan suggest its broad dispersion and migration before settlement     

Sakiko Orui Sakaguchi  Kiyotaka Takishita  Tomoaki Goto  Haruka Shibata  Shigeaki Kojima  Shinji Tsuchida  Hiroshi Kitazato  Katsunori Fujikura 《Journal of Oceanography》2014,70(5):457-462

Body size, age, and population genetic structure of the broadbanded thornyhead Sebastolobus macrochir inhabiting areas off the Pacific coast of Tohoku and off Abashiri, the Sea of Okhotsk, Japan, were analyzed. On the basis of significant differences in body size (growth) between certain year classes at Tohoku and Abashiri, it appears that S. macrochir does not migrate extensively after settlement and subsists on food within the settled environment. Meanwhile, no genetic isolation was observed between the populations at these two sites. Thus, it is highly likely that its pelagic egg balloons, larvae, and juveniles widely disperse and migrate before settlement.  相似文献