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Random inhomogeneities in the northern Izu-Bonin arc estimated by tomographic inversion of peak delay times of S wave seismograms
https://nied-repo.bosai.go.jp/records/4537
https://nied-repo.bosai.go.jp/records/45379a5a3cbd-e03b-44be-95cd-1906b640e586
| Item type | researchmap(1) | |||||||||||||||||||||||||||||||||
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| 公開日 | 2023-03-30 | |||||||||||||||||||||||||||||||||
| タイトル | ||||||||||||||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||||||||||||
| タイトル | Random inhomogeneities in the northern Izu-Bonin arc estimated by tomographic inversion of peak delay times of S wave seismograms | |||||||||||||||||||||||||||||||||
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| 言語 | en | |||||||||||||||||||||||||||||||||
| タイトル | Random inhomogeneities in the northern Izu-Bonin arc estimated by tomographic inversion of peak delay times of S wave seismograms | |||||||||||||||||||||||||||||||||
| 言語 | ||||||||||||||||||||||||||||||||||
| 言語 | eng | |||||||||||||||||||||||||||||||||
| 著者 |
Takahashi Tsutomu
× Takahashi Tsutomu
× Obana Koichiro
× Kodaira Shuichi
× Suetsugu Daisuke
× Takahashi Narumi
× Kamiya Shin'ichiro
× Tamura Yoshihiko
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| 内容記述タイプ | Other | |||||||||||||||||||||||||||||||||
| 内容記述 | Random inhomogeneity in the lithosphere scatters seismic waves at high frequencies (>1 Hz). The accumulated scattering effect of S waves can be measured from the peak delay time, defined as the time lag from the S wave onset to the maximal amplitude arrival. This study estimated the spatial distribution of the power spectral density function (PSDF) of random velocity inhomogeneities in the northern Izu-Bonin arc by inversion analysis of the peak delay times assuming von Karman-type spectrum. Peak delay times were measured at plural frequency bands (4-8, 8-16, and 16-32 Hz) by using waveform data recorded by ocean bottom seismographs. The inversion result at 0-30 km depth shows strong inhomogeneities beneath the Quaternary volcanoes Aoga-shima, Sumisu-jima, and Tori-shima. At 30-70 km depth, strongly inhomogeneous regions were imaged beneath the Quaternary volcanoes and weak inhomogeneities were imaged on the fore-arc side. The PSDF beneath the Quaternary volcanoes was estimated as P(m) similar to 0.029 m(-3.7) km(3) at 0.5 < m < 50 km(-1), where m is the wave number (km(-1)). The PSDF on the fore-arc side is P(m) similar to 0.0023 m(-4.4) km(3). The spectral roll-off is significantly different between these two regions, indicating that differences in random inhomogeneities become pronounced at smaller spatial scales. Petrological studies of the Izu-Bonin Mariana arc have suggested that magma and restite transport occurs across the Moho. We speculate that small magma inclusions or restite may account for the strong inhomogeneities beneath the Quaternary volcanoes and that the stochastic characteristics of their spatial distribution have changed the spectral roll-off there. | |||||||||||||||||||||||||||||||||
| 言語 | en | |||||||||||||||||||||||||||||||||
| 書誌情報 |
ja : JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH en : JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 巻 116, 発行日 2011-03-08 |
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| 言語 | en | |||||||||||||||||||||||||||||||||
| 出版者 | AMER GEOPHYSICAL UNION | |||||||||||||||||||||||||||||||||
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| 収録物識別子タイプ | EISSN | |||||||||||||||||||||||||||||||||
| 収録物識別子 | 2169-9356 | |||||||||||||||||||||||||||||||||
| DOI | ||||||||||||||||||||||||||||||||||
| 関連識別子 | 10.1029/2010JB007691 | |||||||||||||||||||||||||||||||||
