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 S (固体地球科学) » S-TT 計測技術・研究手法

[S-TT51] 地震観測・処理システム

2016年5月23日(月) 10:45 〜 12:00 102 (1F)

コンビーナ:*中村 洋光(防災科学技術研究所)、座長:篠原 雅尚(東京大学地震研究所)

11:15 〜 11:30

[STT51-03] 日本海溝海底地震津波観測網(S-net)-海洋部工事の進捗-

*望月 将志1金沢 敏彦1植平 賢司1藤本 博己1野口 伸一1眞保 敬1汐見 勝彦1功刀 卓1青井 真1松本 拓己1関口 渉次1岡田 義光1篠原 雅尚2山田 知朗2 (1.国立研究開発法人防災科学技術研究所、2.東京大学地震研究所)

キーワード:海底観測網、津波、海底地震

NIED ( National Research Institute for Earth Science and Disaster Prevention ) has launched the project of constructing an observatory network for tsunami and earthquake on the seafloor, after the occurrence of the 2011 off the Pacific coast of Tohoku earthquake by the reflection that we could not monitor the expanse of the earthquake and the tsunami outbreak on site and in real time due to poor coverage of observation in ocean area. The project has been financially supported by MEXT ( Ministry of Education, Culture, Sports, Science and Technology - Japan ).

The observatory network was named “S-net”. S-net consists of 150 seafloor observatories which are connected in line with optical cables. The total length of submarine optical cable is about 5,700km. S-net system extends along Kuril and Japan trenches around Japan islands from north to south covering the area between southeast off island of Hokkaido and off the Boso Peninsula, Chiba Prefecture. Each observatory equips two sets of quartz type pressure gauge and four sets of three-component seismometers. Digitized data from those sensors are transmitted to land and used for early warning and precise measurement for earthquakes and tsunamis.

Two Japanese cable layer ships, which are specially designed for installation and repairing of submarine telecommunication cables, have been used for installation of the S-net submarine cable system. The S-net submarine cable system including the observatories is buried 1m beneath the seafloor to prevent from interference with fishing industry in the area shallower than 1,500m water depth. Those cable layer ships have capabilities of burying submarine cables. The S-net submarine cable system was originally designed to be deployed with the cable layer ships.

Three of authors are now board on C/S SUBARU, which is one of two cable layer ships described above, and in charge of installation of a subset of the S-net submarine observatory network which covers the area between east off Aomori Prefecture and south off island of Hokkaido. Installations of 23 observatories and about 800km length optical cable on the seafloor will be completed shortly after.

We will report the progress of the construction of S-net submarine cable system in this presentation.