Separate extraction of ocean infragravity waves and seismic waves by multi-scale very-broadband observation of water pressure

• Project/Area Number: 23654162
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: FUKAO Yoshio 独立行政法人海洋研究開発機構, 地球内部ダイナミクス領域, チームリーダー (10022708)
• Co-Investigator(Kenkyū-buntansha): SUGIOKA Hiroko 独立行政法人海洋研究開発機構, 地球内部ダイナミクス領域, 研究員 (00359184)
• Project Period (FY): 2011 – 2012
• Project Status: Completed (Fiscal Year 2012)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2012: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2011: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
• Keywords: 海底水圧観測 / 高感度水圧計 / 海洋波動現象 / 海底観測 / 海底地震学 / 水圧計 / 地震計

Research Abstract

We developed an ocean bottom high-resolution water pressure measuring system using a newly released water-pressure sensor counting quartz-oscillation frequency. We installed this observation system on the seafloor off Miyagi prefecture and recovered it after three months. We confirmed that seismic event with magnitudes less than 3 can be detected with high S/N ratios on the 20Hz-sampling records. We also confirmed that by adjusting the sampling rate, the system can record ground noise whose rms amplitude is three orders of magnitude lower than the tremor amplitude in seismically quiet days.

Research Products

• [Journal Article] Shear wave splitting apparently caused by contamination of P-to-S or S-to-P converted waves (2012)
  • Author(s): Yoko Tono
  • Journal Title: Bull. Seismol. Soc. Am. Volume: 103 Issue: 2A Pages: 950-957
  • DOI: 10.1785/0120120090
  • Peer Reviewed
• [Journal Article] Tsunamigenic potential of the shallowest subduction plate boundary inferred from seismic slip (2012)
  • Author(s): Sugioka, H., T. Okamoto, T. Nakamura, Y. Ishihara, A. Ito, K. Obana, M. Kinoshita, K. Nakahigashi, M. Shinohara, Y. Fukao
  • Journal Title: Nature Geoscience Volume: 5 Issue: 6 Pages: 1-3
  • DOI: 10.1038/ngeo1466
  • Peer Reviewed
• [Journal Article] Detection of small earthquakes along the Pacific-Antarctic Ridge from T-waves recorded by abyssal ocean-bottom observatories (2012)
  • Author(s): Ito A.
  • Journal Title: Marine Geophysical Research Volume: - Issue: 3 Pages: 229-238
  • DOI: 10.1007/s11001-012-9158-0
  • Peer Reviewed
• [Journal Article] Seismic reflection imaging of a Warm Core Ring south of Hokkaido (2011)
  • Author(s): Yamashita, M., K. Yokota, Y. Fukao, S. Kodaira, S. Miura, K. Katsumata
  • Journal Title: Exploration Geophysics Volume: 42 Issue: 1 Pages: 18-24
  • DOI: 10.1071/eg11004
  • NAID: 10029437356
  • Peer Reviewed
• [Journal Article] Seismogenic characteristic of the Northern Mariana shallow thrust zone from local array data, Geochm.Geophys (2011)
  • Author(s): E.L.Emry, 他2名,H.Sugioka
  • Journal Title: Geosys Volume: 12, Q12008 Issue: 12 Pages: 25-25
  • DOI: 10.1029/2011gc003853
  • Peer Reviewed
• [Journal Article] Seismic reflection imaging of a Warm Core Ring south of Hokkaido (2011)
  • Author(s): Yamashita, M., K. Yokota, Y. Fukao, S. Kodaira, S. Miura, and K. Katsumata
  • Journal Title: Exploration Geophysics Volume: 42 Pages: 18-24
  • NAID: 10029437356
  • Peer Reviewed
• [Presentation] Subducted slabs stagnant above, penetrating through and trapped below the 660km discontinuity (2013)
  • Author(s): Yoshio Fukao and Masayuki Obayashi
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 千葉市幕張
  • Year and Date: 2013-05-24
• [Presentation] Earthquakes recovering strain energy lost at interseismic stage (2013)
  • Author(s): Yoshio Fukao, Takane Hori,and Shuichi Kodaira
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 千葉市幕張
  • Year and Date: 2013-05-19
• [Presentation] The elastic rebound process of the 2011 Mw.9.0 Tohoku=oki earthquake (2012)
  • Author(s): Yoshio Fukao, Takane Hori, and Shuichi Kodaira
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 千葉市幕張
  • Year and Date: 2012-05-25
• [Presentation] Occurrence of very-low-frequency earthquakes along the decollement of the Nankai trough as evidenced by broadband ocean bottom seismometer observations (2011)
  • Author(s): Fukao, Y. and VLF seminar group
  • Organizer: Asia Oceania Geosciences Societ
  • Place of Presentation: Taipei International Convention Center, 台北
• [Presentation] The 2011 Mw9.0 Tohoku-Oki Earthquake: Joint occurrence of tectonic stress-driven and lithostatic stress-driven slips along the plate boundary (2011)
  • Author(s): Fukao, Y., T. Hori and S. Kodaira
  • Organizer: American Geophysical Union
  • Place of Presentation: Moscone Center, サンフランシスコ
• [Presentation] The elastic rebound process of the 2011 Mw 9.0 Tohoku=oki earthquake
  • Author(s): Yoshio Fukao
  • Organizer: 日本地球惑星科学連合 連合大会
  • Place of Presentation: 千葉市幕張