A study on the lithosphere-asthenosphere boundary using multi-mode surface waves

2013 Fiscal Year Final Research Report

• Project/Area Number: 24740298
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Hokkaido University
• Principal Investigator: YOSHIZAWA Kazunori 北海道大学, 理学(系)研究科(研究院), 准教授 (70344463)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Keywords: 表面波 / トモグラフィー / リソスフェア / アセノスフェア

Research Abstract

We developed a new method for estimating the lithosphere-asthenosphere boundary (LAB) from a 3-D shear wave model and its vertical velocity gradient, derived from multi-mode surface waves. The method is applied to a new anisotropic model of Australia, and the 3-D distribution of LAB, including its depth and thickness, has been estimated successfully. The estimated LAB beneath Australia has been discussed in detail in comparison with the radial anisotropy and earlier results from body-wave receiver functions. We have also developed a new technique for measuring inter-station phase and amplitude of surface waves based on a fully nonlinear waveform fitting. The new method has been applied to USArray, and a preliminary high-resolution phase speed models of North America was constructed. The new method allows us to collect a large number of short inter-station paths (less than 1000km), which can be of great help to enhance the horizontal resolution of shear wave models.

Research Products

• [Journal Article] Australian Seismological Reference Model (AuSREM) : Mantle Component (2013)
  • Author(s): Kennett, B.L.N., Fichtner, A., Fishwick, S. and Yoshizawa, K.
  • Journal Title: Geophys. J. Int. Volume: 192 Pages: 871-887
  • Peer Reviewed
• [Journal Article] Three-dimensional S wave structure of the upper mantle beneath Turkey from surface wave tomography (2012)
  • Author(s): Bakirci, T., Yoshizawa, K. and Ozer, M.F.
  • Journal Title: Geophys. J. Int. Volume: 190 Pages: 1058-1076
  • Peer Reviewed
• [Presentation] Surface-wave amplitude analysis for array data with non-linear waveform fitting : Toward high-resolution attenuation models of the upper mantle (2013)
  • Author(s): Hamada, K. and Yoshizawa, K.
  • Organizer: AGU Fall Meeting
  • Place of Presentation: Moscone Center (San Francisco, USA)
  • Year and Date: 2013-12-11
• [Presentation] B.L.N., Lithosphere-asthenosphere boundary and radial anisotropy of the Australian continent from multi-mode surface waves (2013)
  • Author(s): Yoshizawa, K. and Kennett
  • Organizer: AGU Fall Meeting
  • Place of Presentation: Moscone Center (San Francisco, USA)
  • Year and Date: 2013-12-10
• [Presentation] 豪州大陸下のリソスフェア-アセノスフェア境界の地震学的検出 (2013)
  • Author(s): 吉澤和範, Kennett, B.L.N.
  • Organizer: 日本地震学会秋季大会
  • Place of Presentation: 産業貿易センター(横浜市)
  • Year and Date: 2013-10-08
• [Presentation] 非線形波形フィッティングを用いた表面波振幅解析による北米大陸の減衰構造 (2013)
  • Author(s): 浜田広太, 吉澤和範
  • Organizer: 日本地震学会秋季大会
  • Place of Presentation: 産業貿易センター(横浜市)
  • Year and Date: 2013-10-08
• [Presentation] Mapping the Australian upper mantle with multi-mode surface waves : Radial anisotropy and the lithosphere-asthenosphere boundary (2013)
  • Author(s): Yoshizawa, K. and Kennett, B.L.N.
  • Organizer: IAHS-IAPSO-IASPEI Joint Assembly 2013
  • Place of Presentation: Gothenburg Convention Centre (Gothenburg, Sweden)
  • Year and Date: 2013-07-24
• [Presentation] Measurements of inter-station phase speeds and attenuation of surface waves in North America with USArray (2013)
  • Author(s): Hamada, K. and Yoshizawa, K.
  • Organizer: IAHS-IAPSO-IASPEI Joint Assembly 2013
  • Place of Presentation: Gothenburg Convention Centre (Gothenburg, Sweden)
  • Year and Date: 2013-07-24
• [Presentation] 豪州大陸下の上部マントル鉛直異方性とリソスフェア-アセノスフェア境界 (2013)
  • Author(s): 吉澤和範, Kennett, B.L.N.
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 幕張メッセ(千葉市)
  • Year and Date: 2013-05-24
• [Presentation] USArrayを用いた北米大陸の減衰構造 : 非線形波形フィッティングによる表面波振幅の2点法解析 (2013)
  • Author(s): 浜田広太, 吉澤和範
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 幕張メッセ(千葉市)
  • Year and Date: 2013-05-24
• [Presentation] マルチモード表面波を用いたリソスフェア-アセノスフェア境界の推定 (2012)
  • Author(s): 吉澤和範
  • Organizer: 日本地震学会秋季大会
  • Place of Presentation: 函館市民会館・体育館(函館市)
  • Year and Date: 2012-10-18
• [Presentation] USArrayを用いた北米大陸の減衰構造 : 2点法による表面波振幅解析 (2012)
  • Author(s): 浜田広太, 吉澤和範
  • Organizer: 日本地震学会秋季大会
  • Place of Presentation: 函館市民会館・体育館(函館市)
  • Year and Date: 2012-10-18
• [Presentation] Mapping the upper mantle with multi-mode surface waves : Application to the Australian region (2012)
  • Author(s): Kennett, B.L.N. and Yoshizawa, K.
  • Organizer: 34th International Geological Congress
  • Place of Presentation: Brisbane Convention Centre (Brisbane, Australia)
  • Year and Date: 2012-08-08
• [Presentation] マルチモード表面波による大陸リソスフェアの3次元イメージング (2012)
  • Author(s): 吉澤和範
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 幕張メッセ(千葉市)
  • Year and Date: 2012-05-20
• [Book] 「地球の物理学事典」(共訳) (2013)
  • Author(s): 本多了, 岩森光, 歌田久司, 大久保修平, 栗田敬, 土屋卓久, 中井俊一, 平賀岳彦, 宮武隆, 吉澤和範
  • Total Pages: 519(243-294)
  • Publisher: 朝倉書店