Geological and microbial anomalies in the extinct submarine volcano, Shiribeshi Seamount, in the eastern margin of the Japan Sea     

MARI  OGAWA  AKIRA  TAKEUCHI  MUTSUO  HATTORI  MASAHARU  OKANO  MISUMI  AOKI  MAKIKO  IMAMURA  TOYOKI  KSUBOI  TOMONORI  TSUBOI  DAISUKE  TANIMOTO  TAKESHI  NAGANUMA 《Island Arc》2002,11(4):274-286

Abstract   The manned submersible Shinkai 2000 investigated yellow patches on the near-summit slope of Shiribeshi Seamount in the Japan Sea. Yellowish patches are often associated with seepage, and the possibility of seepage at Shiribeshi Seamount was tested by the following four lines of observation: (i) high subsurface temperature was measured at a ring-like patch, although no increase in subsurface temperature was observed at other patches; (ii) high gamma ray (γ-ray) intensity from the thorium series was recorded in the patch zone; (iii) the yellowish deposit was composed of calcite, quartz and amorphous iron compound, as seen at the yellowish patches in other seeps and volcanoes; (iv) lipid phosphate, a measure of microbial abundance, in sediments of the ring-like patch was determined, and the recorded microbial abundance was higher inside the patch than outside it. The four lines of observation are explained consistently by postulating that the seepage of warm fluid contained Fe and γ-ray sources. A hydrothermal origin of the yellow patches is not ruled out for the extinct but young (0.9 Ma) arc volcano.  相似文献   

Three-Dimensional Numerical Model for Tsunami Propagation Passing Through An Obstacle     

Sung Jin HONG Byung Ho CHOI Fumihiko IMAMURA 《中国海洋工程》2006,20(3):509-516

1 .Introduction In the present numerical analysis of a tsunami ,atwo-dimensional numerical model based on non-linear shallowwater theoryis mainly used (Aburaya and Imamura ,2002 ;Imamura ,1995 ; Goto andOgawa ,1992) .Thoughthis model representstsunami hei…  相似文献