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| Titel |
First attenuation study at Usu volcano (Hokkaido, Japan) |
| VerfasserIn |
Janire Prudencio, Taka'aki Taira, Luca De Siena, Shin'ya Onizawa, Jesús Ibáñez, Margaret Hellweg, Edoardo Del Pezzo, Hiroshi Aoyama, Araceli Garcia-Yeguas, Hiromitsu Oshima, Alejandro Díaz-Moreno |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250092549
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| Publikation (Nr.) |
 EGU/EGU2014-6902.pdf |
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| Zusammenfassung |
| 2D and 3D attenuation structures of Usu volcano has been obtained with measurements of diffusion model and coda-normalization method, respectively, with the same data-set used to develop the 3D velocity tomography by Onizawa et al., (2007).
We have obtained intrinsic and scattering 2D maps applying the diffusion model which is an approximation of the general energy transport theory developed by Wegler and Lühr (2001) and Wegler (2003). As a result of the theoretical curves with the energy envelopes of the seismograms, we have obtained intrinsic attenuation coefficient and diffusivity coefficient values in the frequency range of 4-16 Hz. Then, We have quantified the contribution of intrinsic and scattering attenuation by inverse quality factor because is more representative. Finally, with a new representation method based in the Gaussian probability function distribution, we have represented the inverse quality factors obtained into 2D contour maps.
To obtain 3D attenuation tomography of Deception Island, we have used more than 2000 waveforms recorded at over 288 on land seismic stations. The rays were traced in a 3D velocity model. We have inverted the spectral ratios obtained with the coda normalization method to obtain total-Q values. We resolve 1 km cubic cells.
Both results, 2D maps and 3D attenuation structure, have shown that there is likewise agreement with the velocity tomography: the low velocity zones being consistent with regions featuring high attenuation effects and the high velocity zones with regions featuring low attenuation effects. This new models will be a complement to the better understanding of velocity anomalies and will allow remove some grades of uncertainty of the other studies. |
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