1990 Fiscal Year Final Research Report Summary
Measurement of Elastic Wave Velocity of Mg Perovskite Unter High Pressures and Materials of the Lower Mantle
| Project/Area Number |
01540327
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体地球物理学
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| Research Institution | Earthquake Research Institute, University of Tokyo |
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Principal Investigator |
FUJISAWA Hideyuki Earthquake Research Inst., University of Tokyo, Assistant, 地震研究所, 助手 (50012927)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Magnesium Perovskite / Elastic Wave Velocity / 670km Discontinuity / High Pressure Experiment / Lower Mantle / Mantle Minerals |
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| Research Abstract |
All through the measurement under high pressures which correspond to the earth's lower mantle we have to use a very small sample, the length of which is a few millimeter, because an available volume in the high pressure apparatus under such conditions is very limitted.
There exists no natural Mg perovskite, and we have to use a synthesized sample.
First of all we have to develop a electronic system for the accurate measurement of elastic wave velocity with a very small mineral sample, because no such system has not yet existed in the world. We have modified our original system for the measurements of velocities of the upper mantle minerals.
Mg perovskite samples was synthesized under pressures more than 20GPa by Prof. E. Ito of Institute for Study of the Earth's Interior, Okayama University. The length of sample is about 2mm, the diameter is about 1mm.
With the modified system we first tried to observe a transmitted signal through this small diameter. The simple observation of this kind of signals has been very successful.
However, in successive trials to measure pressure dependence of the velocity we have not been able to observe clear signals under high pressures.
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