11:45 AM - 12:00 PM
[MIS11-11] A preliminary report on a flume experiment of Tsunami-generated turbidity currents and sediment transport
Keywords:Tsunami, Turbidity currents, Sediment transport, Flume experiment
The experiment was conducted using 7.2 m long, 1.2 m deep, and 0.3 m wide flume in Osaka Institute of Technology. We made two terrain models, one referred the profile of Kumano-Nada region which has a steeper slope, and the other referred the profile of Tokachi-oki region which has a shallower slope. The models were made of very coarse sand and granule, and mantled by fine to very fine sand about 5 cm in thickness. The horizontal and vertical ratio of the profiles is 1:100. We generated “tsunami” by the acrylic plate, in the way as same as that of Niitani et al. (2013), and repeated “tsunami” 10 times for each profile.
As the results, turbidity currents occurred in both cases. The amount of entrainment of sediment by the “tsunami” was larger in the steeper “Kumano-nada” model, and the velocity of the turbidity currents was larger for and total amount of sediment transport was larger for the steeper model. The relict bedforms, however, showed more wave-dominated features in the case of steeper “Kumano-nada” model.
Arai, K., Naruse, H., Miura, R, Kawamura, K., Hino, R., Ito, Y., Inazu, D., Yokokawa, M., Izumi, N., Murayama M. and Kasaya, T., 2013, Tsunami-generated turbidity current of the 2011 Tohoku-Oki earthquake, Geology, 41, 1195-1198, doi: 10.1130/G34777.1.
Niitani, S., Masuda, F., and Naruse, H., 2013, Tsunami-induced gravity currentsgenerated in an experimental flume. Journal of Sedimentary Society of Japan, 72, 109-113. (in Japanese with English abstract)