Investigation for geodetic detection of variation in crustal deformation near the subduction plate boundary

俯冲板块边界附近地壳变形变化的大地测量研究

• 批准号: 15340142
• 负责人: FUJIMOTO Hiromi
• 金额: $ 10.69万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15340142/
• 关键词: subduction plate boundary; plate motion; seismic coupling; seafloor geodetic observation; precise seafloor positioning; ocean bottom pressure monitoring; Japan trench; off Fukushima Prefecture; 宮城県沖; 非地震性すべり; 海底精密測位観察; 海陸プレート境界; 精密測位観測; 海底傾斜観

The objectives of this research program are to investigate for spatial and temporal variations in crustal deformation induced by the subducting plate motion through seafloor geodetic observation in the vicinity of the subduction plate boundary, and to estimate the repeatability of the seafloor geodetic observation.Repeated precise seafloor positioning based on sea surface KGPS positioning and underwater acoustic ranging has been carried out off Iwate and Miyagi prefectures, and has been initiated off Fukushima Prefecture. Judging from seismic activities off Fukushima, seismic coupling on the plate boundary in the region can be relatively weak. However, land-based GPS observation in these several years suggests strong coupling off Fukushima as well as off Miyagi. Although the estimated error is fairly large in the crustal deformation obtained from two-year observations, the result shows that the seismic coupling off Fukushima is as strong as that off Miyagi. The coupling off Fukushima may possibly show temporal variation.GPS/Acoustic (GPS/A) seafloor positioning off Kii Peninsula detected a large co-seismic crustal movement up to 30 cm associated with the 2004 earthquake (M7.4) off Kii Peninsula. The repeatability of the positioning obtained from an observation for two days is estimated to be about 3-5 cm. This value was larger than the estimated displacements at our GPS/A sites associated with the 2005 earthquake off Miyagi Prefecture. We confirmed that the value can be improved with higher GPS sampling.Long-term ocean bottom pressure monitoring was carried out off Iwate Prefecture under two crossover points of the satellite tracks for altimetry. The results coincide with recent five ocean tide models within 1.3 cm in terms of root sum square of vector differences for eight principal constituents. Although we have acquired know-how for long-term ocean bottom pressure monitoring, we need more research works to get long-term stability of pressure monitoring.

本研究项目的目的是通过在俯冲板块边界附近进行海底大地测量观测，调查俯冲板块运动引起的地壳形变的时空变化，并对海底大地测量观测的重复性进行评估。在岩手县和宫城县近海，进行了基于海面KGPS定位和水声测距的重复性精确海底定位，并已在福岛县附近启动。从福岛近海的地震活动来看，该地区板块边界上的地震耦合可能相对较弱。然而，这几年的陆基GPS观测表明，福岛和宫城外海存在较强的耦合。虽然两年观测所得的地壳形变估计误差较大，但结果表明，福岛与宫城的地震耦合作用相当强。福岛外的耦合可能表现出时间变化。纪伊半岛外的GPS/声学（GPS/A）海底定位检测到与2004年纪伊半岛外地震（M7.4）相关的大的同震地壳运动，最大可达30 cm。从两天的观测中获得的定位的可重复性估计为约3- 5cm。该值大于2005年宫城县外地震时GPS/A站点的估计位移。我们证实，该值可以提高与更高的GPS采样。长期的海底压力监测岩手县下的两个交叉点的卫星轨道测高。在1.3cm范围内，8个主分潮矢量差的平方根和与最近5个海潮模型的结果相吻合。虽然我们已经获得了长期海底压力监测的技术，但我们需要更多的研究工作，以获得长期稳定的压力监测。

项目成果

Ocean bottom pressure observation off Sanriku and comparison with ocean tide models, altimetry, and barotropic signals from ocean models

• DOI: 10.1029/2006gl026706
• 发表时间: 2006-08
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Koji Matsumoto;Tadahiro Sato;Hiromi Fujimoto;Y. Tamura;M. Nishino;Ryota Hino;Toshihiro Higashi;Toshihiko Kanazawa

The 2003 M8.0 Tokachi-Oki earthquake - How much has the great event paid back slip debts?

• DOI: 10.1029/2003gl019021
• 发表时间: 2004-03-11
• 期刊: GEOPHYSICAL RESEARCH LETTERS
• 影响因子: 5.2
• 作者: Miura, S;Suwa, Y;Nishimura, T
• 通讯作者: Nishimura, T

Initial results of GPS/Acoustic seafloor positioning using a small towed buoy off Miyagi Prefecture, northeastern Japan

使用日本东北部宫城县附近的小型拖曳浮标进行 GPS/声学海底定位的初步结果

• 发表时间: 2006
• 期刊: J.Geod.Soc.Japan 52(2)
• 作者: Funakoshi;M.;Y.Osada;S.Miura;M.Nishino;A.Kuwano;R.Hino;H.Fujimoto
• 通讯作者: H.Fujimoto

三陸沖光ケーブル式海底地震津波観測亜システムによる津波観測

使用 Sanriku-Oki 光缆海底地震和海啸观测子系统进行海啸观测

• 发表时间: 2005
• 期刊: 月刊地球 37・3
• 作者: 日野亮太;藤本博巳;他;日野亮太
• 通讯作者: 日野亮太

Fujimoto, H.: "Seafloor geodesy and an ocean bottom cable system"Scientific Submarine Cable 2003 Workshop(SSC'03),25-27 June 2003,Tokyo, IEEE Catalogue. 03EX660. 251-254 (2003)

Fujimoto, H.：“海底大地测量和海底电缆系统”2003 年科学海底电缆研讨会(SSC03)，2003 年 6 月 25-27 日，东京，IEEE 目录。