Estimation of the occurrence condition of sediment resuspension in Osaka Bay by Tsunami

Mitsuru Hayashi, Soto Suzuki, Satoshi Nakada, Shunichi Koshimura, Ei Ichi Kobayashi

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    4 Citations (Scopus)

    Abstract

    The non-dimensional bed shear stress in Osaka Bay by a tsunami caused by the Nankai Trough Earthquake was calculated, and the conditions under which the resuspension of marine sediments would occur were determined in every region of Osaka Bay. Resuspension does not occur in the western part of Osaka Bay, where the predicted maximum flow velocity of the tsunami is 1.8 m/s, under the present condition of the water depth and the moisture content. On the other hand, resuspension does occur in the eastern part of Osaka Bay by the predicted tsunami. The occurrence and the scale of the resuspension in the eastern part depend on the moisture content and the flow velocity of the tsunami. An extremely strong resuspension will occur continuously throughout a tsunami hitting the estuary with over 72 % moisture content. The scale of the resuspension in such a "hot spot" is determined by the moisture content. Marine sediments contain cysts and heavy metals, especially in the estuary. We are afraid that resuspension of the sediment may lead to red tide and water pollution over a wide area due to advection after the tsunami.

    Original languageEnglish
    Title of host publicationProceedings of the 25th International Ocean and Polar Engineering Conference, ISOPE 2015
    PublisherInternational Society of Offshore and Polar Engineers
    Pages783-788
    Number of pages6
    ISBN (Electronic)9781880653890
    Publication statusPublished - 2015 Jan 1
    Event25th International Ocean and Polar Engineering Conference, ISOPE 2015 - Kona, Big Island, United States
    Duration: 2015 Jun 212015 Jun 26

    Publication series

    NameProceedings of the International Offshore and Polar Engineering Conference
    Volume2015-January
    ISSN (Print)1098-6189
    ISSN (Electronic)1555-1792

    Other

    Other25th International Ocean and Polar Engineering Conference, ISOPE 2015
    Country/TerritoryUnited States
    CityKona, Big Island
    Period15/6/2115/6/26

    Keywords

    • Kicking up
    • Nankai Trough
    • Osaka Bay
    • Resuspension
    • Sediment
    • Shear stress
    • Tsunami

    ASJC Scopus subject areas

    • Energy Engineering and Power Technology
    • Ocean Engineering
    • Mechanical Engineering

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