Investigation of excitation sources of Earth's background free oscillations from acoustic resonance

• Project/Area Number: 19740268
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Solid earth and planetary physics
• Research Institution: The University of Tokyo
• Principal Investigator: NISHIDA Kiwamu The University of Tokyo, 地震研究所, 助教 (10345176)
• Project Period (FY): 2007 – 2009
• Project Status: Completed (Fiscal Year 2009)
• Budget Amount: ¥2,920,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥420,000); Fiscal Year 2009: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2008: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2007: ¥1,100,000 (Direct Cost: ¥1,100,000)
• Keywords: 地球自由振動 / 大気音波 / 音波 / 大気自由振動 / 音響結合 / 常時地球自由振動 / 大気圧観測 / 表面波

Research Abstract

In this study we showed clear evidence of background Love waves from 10 to 20 mHz. The observed kinetic energy of Love waves is as large as that of Rayleigh waves through the whole period of analysis. We propose that the most likely excitation source is shear traction acting on a sea-bottom horizon due to linear topographic coupling of infragravity waves.

Research Products

• [Journal Article] Seafloor topography, ocean infra -gravity waves and background Love and Rayleigh waves (2010)
  • Author(s): Fukao, Y., K. Nishida, N. Kobayashi
  • Journal Title: JGR 115,B04302 Pages: 10-10
• [Journal Article] Seafloor topography, ocean infragravity waves and background Love and Rayleigh waves (2010)
  • Author(s): Fukao, Y., K.Nishida, N.Kobayashi
  • Journal Title: JGR 115
  • Peer Reviewed
• [Journal Article] Global Surface Wave Tomography Using Seismic Hum (2009)
  • Author(s): Nishida, K., J.P. Montagner, H. Kawakatsu
  • Journal Title: Science Vol.326,5949 Pages: 112-112
  • Peer Reviewed
• [Journal Article] 常時地球自由振動 (2009)
  • Author(s): 西田究
  • Journal Title: 地震2 61
  • NAID: 10025364847
  • Peer Reviewed
• [Journal Article] Global Surface Wave Tomography Using Seismic Hum (2009)
  • Author(s): Nishida, K., J.P.Montagner, H.Kawakatsu
  • Journal Title: Science 326 Pages: 112-112
  • Peer Reviewed
• [Journal Article] 常時地球自由振動 (2009)
  • Author(s): 西田究
  • Journal Title: 地震 (印刷中)(掲載確定)
  • NAID: 10025364847
  • Peer Reviewed
• [Journal Article] Background Love and Rayleigh waves simultaneously generated at the Pacific Ocean floors (2008)
  • Author(s): Nishida, K., H. Kawakatsu, Y. Fukao, K. Obara
  • Journal Title: Geophys. Res. Lett. Vol35
  • Peer Reviewed
• [Journal Article] Three-dimensional crustal S wave velocity structure in Japan using micrgseismic data recorded by Hi-net tiltmeters (2008)
  • Author(s): Kiwamu Nishida
  • Journal Title: J. Geophys. Res. 113
  • Peer Reviewed
• [Journal Article] Background Love and Rayleigh waves simultaneously generated at the Pacific Ocean floors (2008)
  • Author(s): Kiwamu Nishida
  • Journal Title: Gephys. Res. Lett. 35
  • Peer Reviewed
• [Journal Article] 常時地球自由振動 (2008)
  • Author(s): 西田究
  • Journal Title: 地震 (印刷中)
  • NAID: 10025364847
  • Peer Reviewed
• [Journal Article] Background Love and Rayleigh waves simultaneously generated at the Pacific Ocean floors (2008)
  • Author(s): 西田究
  • Journal Title: Geohpys. Res. Let. 35
  • Peer Reviewed
• [Journal Article] Three-dimensional crustal S wave velocity structure in Japan using microseismic data recorded by Hi-net tiltmeters (2008)
  • Author(s): 西田究
  • Journal Title: J. Geohpys. Res. 113
  • Peer Reviewed
• [Journal Article] Source distribution of Earth's background free oscillations (2007)
  • Author(s): Nishida, K., Y. Fukao
  • Journal Title: J. Geophys. Res. Vol.112
  • Peer Reviewed
• [Presentation] MeSO-net に記録された脈動記録を用いた関東平野S 波速度構造の推定 (2009)
  • Author(s): 西田究, 利根川貴志, 中川茂樹, 酒井慎一, 笠原敬司, 棚田俊牧, 小原一成, 平田直
  • Organizer: 地震学会
  • Place of Presentation: 京都
  • Year and Date: 2009-10-23
• [Presentation] Global surface wave tomography using seismic hum (2008)
  • Author(s): Kiwamu Nishida
  • Organizer: AGU fall meeting
  • Place of Presentation: サンフランシスコ
  • Year and Date: 2008-12-17
• [Presentation] 大気・海洋・固体地球系の地震学 (2008)
  • Author(s): 西田究
  • Organizer: 地球電磁気・地球惑星圏学会第124回総会及び講演会
  • Place of Presentation: 仙台
  • Year and Date: 2008-10-11
• [Remarks]
  • URL: http://www.eri.u-tokyo.ac.jp/knishida
• [Remarks]
  • URL: http://www.eri.u-tokyo.ac.jp/knishida