Project/Area Number |
17340151
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Geology
|
Research Institution | National Institute of Advanced Industrial Science and Technology |
Principal Investigator |
IKEHARA Ken National Institute of Advanced Industrial Science and Technology, Institute of Geology and Geoinformation, AIST, Research Group Leader (40356423)
|
Co-Investigator(Kenkyū-buntansha) |
KATAYAMA Hajime Inst. of Geology and Geoinformation, Senior Research Scientist (90356775)
NODA Atsushi Inst. of Geology and Geoinformation, Research Scientist (50357745)
TUZINO Taqumi Inst. of Geology and Geoinformation, Research Scientist (80357516)
IRINO Tomohisa Hokkaido Univ., Graduate School of Env. Earth Sci., Assistant Prof. (70332476)
OMURA Akiko University of Tokyo, Ocean Research Institute, Assistant Prof. (80401298)
|
Project Period (FY) |
2005 – 2007
|
Project Status |
Completed (Fiscal Year 2007)
|
Budget Amount *help |
¥12,310,000 (Direct Cost: ¥11,200,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2007: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2006: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2005: ¥4,400,000 (Direct Cost: ¥4,400,000)
|
Keywords | flood / sea floor environment / bottom sediment / natural hazard / 台風 / 北海道日高地方 |
Research Abstract |
Floods supply large amounts of terrigenous materials to marine environments that affects sea bottom environments and strata formation. Quick deposition of large amount of sediments on sea floor may influence to sea floor environments. Because of few marine geological and sedimentological surveys have been conducted immediately after floods, behavior of flood sediments in marine environments and sedimentary processes are not well understood. In August 2003, heavy rain associated with by the typhoon 200310 caused flooding and landslides in Hidaka area, Hokkaido large amount of sand and mud were transported by rivers to ocean. Our survey indicated the two modes of flood mud deposition on the shelf. One is transportation by density (hyperpycnal) flows. Long distance transport across shelf was available by this mechanism. Another is diverse by hypopycnal surface plume. Flood mud was deposited near the river mouth by this system. Inner shelf submarine topography controls such a transportation mode. Taking into account of flood mud deposition on the outer shelf to deep-sea basin floor, the larger amount of terrigenous materials than those previously estimated from river observations were supplied to ocean by this flood. There results verify the importance of the hyperpycnal flow for long-distance transport of the terrigeouns materials to the deep-sea, and flood plays an important role on material supply to deep-sea.
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