日本地球惑星科学連合2016年大会

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セッション記号 H (地球人間圏科学) » H-DS 防災地球科学

[H-DS19] 津波とその予測

2016年5月25日(水) 09:00 〜 10:30 201A (2F)

コンビーナ:*行谷 佑一(国立研究開発法人 産業技術総合研究所 活断層・火山研究部門)、今井 健太郎(国立研究開発法人 海洋研究開発機構)、座長:対馬 弘晃(気象庁気象研究所)、前田 拓人(東京大学地震研究所)

10:15 〜 10:30

[HDS19-06] ガウス過程を用いたDONET水圧データによる沿岸津波高予測

*五十嵐 康彦1村田 伸1馬場 俊孝2佐藤 憲一郎3堀 高峰3岡田 真人1 (1.東京大学大学院新領域創成科学研究科、2.徳島大学大学院ソシオテクノサイエンス研究部、3.海洋研究開発機構地球津波海域観測研究開発センター)

キーワード:津波高予測、ガウス過程、DONET

In Japan, the Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) was recently developed in the Nankai trough (Kaneda et al., 2015). DONET1 is equipped with seismometers and ocean-bottom pressure gauges at 20 points on the sea floor and submarine data can be acquired in real time. We studied the relationship between offshore and coastal tsunami heights with the aim of using DONET1 ocean-bottom pressure gauges for early tsunami prediction.
Previous works focused on the average of maximum absolute values of the hydrostatic pressure changes during a tsunami (Baba et al., 2013). Although compressing time series of pressure gauges data, they revealed a clear relationship between the average waveforms of DONET and tsunami heights at the coast. However, since they assumed linear relationship and used only the average of the data at all the DONET stations, it may be inadequate to take accurate tsunami prediction.
Here, using a standard nonlinear regression method, Gaussian process (GP), we construct an algorithm to predict maximum tsunami height. We found a greatly improved generalization error of the maximum tsunami height by our prediction model. The error is about one third of that by a previous method. Moreover, by optimizing each sensor’s weight of GP, we investigate the contributions of each ocean-bottom pressures on the predictions, which enables us to take more accurate prediction of tsunami height and could provide the design criteria of ocean-bottom sensors in the future.