Detail structure of the large low shear velocity province at the base of the mantle, estimated by waveform modelling of S waves
| Project/Area Number |
23740345
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Solid earth and planetary physics
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| Research Institution | Japan Agency for Marine-Earth Science and Technology |
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Principal Investigator |
TO Akiko 独立行政法人海洋研究開発機構, 地震津波海域観測研究開発センター, 研究員 (70587344)
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| Project Period (FY) |
2011-04-28 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2013: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2011: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | コア-マントル境界 / 実体波 / 広域低速度領域 / スペクトル要素法 / 地球内部構造 / コア－マントル境界 / LLSVP / コアーマントル境界 |
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| Outline of Final Research Achievements |
The aim of this project was to investigate the detail structure of slow seismic velocity anomaly at the base of the mantle and to estimate the form of the mantle upwelling flow. The amplitude of direct S waves for earthquakes in Western Pacific recorded at U.S. are anomalously small. The results of waveform forward modelling show that a previously proposed cylindrical ultra low velocity zone placed at the base of the mantle can be one of the cause of the anomalous S wave amplitudes. The result also shows that due to a finite frequency effect, it is often difficult to distinguish whether the distortion of S waveforms is caused by a large low shear velocity province or an ultra velocity zone at the base of the mantle. The result infers that what is seen as a large low shear velocity province in tomographic models could be in reality a cluster of plumes, whose images are blurred due to technical limitations in handing the finite frequency effect of S waves.
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Report
(5 results)
Research Products
(10 results)
