2016 Fiscal Year Final Research Report
High-resolution mapping of the lithosphere-asthenosphere boundary with seismic wave analysis
| Project/Area Number |
26400443
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Solid earth and planetary physics
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| Research Institution | Hokkaido University |
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Principal Investigator |
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| Research Collaborator |
Kennett Brian L. N.
HAMADA KOUTA
NARITA RYOU
MATSUZAWA HITOSHI
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | リソスフェア / アセノスフェア / 表面波 / 上部マントル |
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| Outline of Final Research Achievements |
Lithosphere-asthenosphere boundaries beneath continental and oceanic regions are estimated from high-resolution 3-D S wave speed models derived from simultaneous inversions of multi-mode Love and Rayleigh waves. We also investigated the effects of arbitrary selection of independent parameters for radial anisotropy of shear waves. New radial anisotropy models in Australia and Pacific regions exhibit conspicuous radial anisotropy with SH>SV in the asthenosphere, indicating the effects of strong shear at the base of the fast drifting lithosphere. We also found that the estimated depths of Mid-Lithosphere Discontinuity (MLD) in the continental lithosphere from S-wave receiver functions coincide well with the inflection point of vertical profiles of radial anisotropy, which is likely to be related to the existence of fine-scale laminated random heterogeneities in the lithosphere.
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| Free Research Field |
地震学
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