Japan Geoscience Union Meeting 2016

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Symbol H (Human Geosciences) » H-DS Disaster geosciences

[H-DS19] Tsunami and Tsunami Forecast

Wed. May 25, 2016 1:45 PM - 3:15 PM 201A (2F)

Convener:*Yuichi Namegaya(Institute of Earthquake and Volcano Geology, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology), Kentaro Imai(Japan Agency for Marine-Earth Science and Technology), Chair:Satoshi Nakada(Graduate School of Maritime Sciences, Kobe University), Takashi Yanuma(PASCO Corporation)

2:30 PM - 2:45 PM

[HDS19-16] Initial tsunami height estimated by observing tsunami ionospheric hole

*Yuto Tomida1, Masashi Kamogawa1, Tatsuya Kanaya1, Atsushi Toyoda2 (1.Department of Physics, Tokyo Gakugei University, 2.Nuclear Safety Research and Development Center, Chubu Electric Power Co., Omaezaki, Japan .)

Keywords: Ionospheric hole , Inland earthquake, Tsunami

Low frequency acoustic waves, termed infrasonic waves, are excited by sudden displacement of ground and sea surface of mega-scale earthquake (EQ) and tsunami. When the waves reach ionosphere, they disturb the ionospheric plasma. The plasma variation has been detected by measurement of total electron contents (TEC) between a satellite of Global Positioning Systems (GPS) and a receiver on the ground. In addition to the waves, a TEC depression lasting for a few minutes to tens of minutes also occurred above the tsunami source area, termed tsunami ionospheric hole (TIH), in the mega-scale EQ with tsunami. The largest of the TEC depression appeared 10 to 20 minutes after the main shock. In this paper, we show the quantitative relation between an initial tsunami height and a depression rate of TEC caused by the TIH. Accordingly, the ionospheric TEC measurement is applicable to an early warning system of tsunami, when it takes more than 20 minutes for the tsunami to arrive coastal area.