RESEARCH ON REALTIME TSUNAMI DETECTION SYSTEM USING OFFSHORE WATER SURFACE ELEVATION DATA

• SHIMIZU Katsuyoshi

  (独) 港空研 海洋・水工部海象情報研究室

• NAGAI Toshihiko

  (独) 港空研 海洋・水工部

• LEE Jae Hyeng

  (財) 沿岸技術研究センター

• IZUMI Hiroaki

  (財) 日本気象協会首都圏支社

• IWASAKI Mineo

  (社) 海洋調査協会専務理事

• FUJITA Takashi

  日立造船 (株) 技術研究所

Bibliographic Information

Other Title

• 沖合水面変動記録を用いた津波成分即時抽出法に関する研究

Abstract

This paper introduces a newly developed real time tsunami detection system using offshore water surface elevation data obtained from GPS buoys or seabed installed acoustic/pressure wave gauges. In order to eliminate high frequency components caused by wind waves and swells, shape of the numerical low-pass-filter was determined with consideration of its real-time efficiency. To eliminate lower frequency phenomena caused by astronomical tides and other causes such as water temperature change, 6 days continuous passed data were found to be necessary to obtain harmonic constants of the 4 principal tide components and averaged sea level. Miss-fixed and data-loss phenomena, which may appear in the GPS buoy observation, were also considered to elaborate the automatic system.<BR>Proposed system was checked with the actual offshore tsunami observation data caused by the 2004 Tokaido-off and 2005 Miyagi-off earthquake tsunami events, and the applicability was well confirmed with exception during a huge typhoon caused abnormal waves and sea-level events.

Journal

• PROCEEDINGS OF CIVIL ENGINEERING IN THE OCEAN

  PROCEEDINGS OF CIVIL ENGINEERING IN THE OCEAN 22 523-528, 2006

  Japan Society of Civil Engineers

Keywords

• tsunami
• offshore observation
• GPS buoy
• seabed wave gauge
• numerical filtering

Details

• CRID: 1390001205204204416
• NII Article ID: 130003950494
• DOI: 10.2208/prooe.22.523
• ISSN: 18848265
• ISSN: 09127348
• Text Lang: ja
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed