Temporal changes of the crustal structure associated with the M6.1 earthquake on September 3, 1998, and the volcanic activity of Mount Iwate, Japan
抄録
<jats:p>We detected temporal changes of crustal structure by cross spectrum analyses of seismic waves excited by two artificial explosions that were carried out about one month before and two months after a M6.1 shallow earthquake. Phase spectrum analysis shows that seismic velocity of the upper crust around the focal area of the M6.1 earthquake and Mount Iwate decreased 0.3–1.0% during the three months. Since lager decreases of the seismic velocity were observed at the region close to the focal area and a volcanic pressure source, we conclude that stress change in the upper crust is a most plausible candidate to cause the velocity changes among other candidates. We further apply a coherence analysis to the observed seismic coda to locate regions where short‐wavelength heterogeneity temporally changed. The result indicates a possibility of temporal changes of the heterogeneity beneath the volcano, where a magmatic fluid intrusion is inferred.</jats:p>
収録刊行物
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- Geophysical Research Letters
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Geophysical Research Letters 27 (2), 269-272, 2000-01-15
American Geophysical Union (AGU)
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詳細情報 詳細情報について
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- CRID
- 1360574096176027008
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- NII論文ID
- 80011409247
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- ISSN
- 19448007
- 00948276
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- データソース種別
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