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| Titel |
Effect of heterogeneities on evaluating earthquake triggering of volcanic eruptions |
| VerfasserIn |
J. Takekawa, H. Mikada, T. Goto |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 13, no. 2 ; Nr. 13, no. 2 (2013-02-07), S.231-237 |
| Datensatznummer |
250017563
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| Publikation (Nr.) |
 copernicus.org/nhess-13-231-2013.pdf |
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| Zusammenfassung |
| Recent researches have indicated coupling between volcanic eruptions and
earthquakes. Some of them calculated static stress transfer in subsurface
induced by the occurrences of earthquakes. Most of their analyses ignored
the spatial heterogeneity in subsurface, or only took into account the
rigidity layering in the crust. On the other hand, a smaller scale
heterogeneity of around hundreds of meters has been suggested by geophysical
investigations. It is difficult to reflect that kind of heterogeneity in
analysis models because accurate distributions of fluctuation are not well
understood in many cases. Thus, the effect of the ignorance of the smaller
scale heterogeneity on evaluating the earthquake triggering of volcanic
eruptions is also not well understood. In the present study, we investigate
the influence of the assumption of homogeneity on evaluating earthquake
triggering of volcanic eruptions using finite element simulations. The crust
is treated as a stochastic media with different heterogeneous parameters
(correlation length and magnitude of velocity perturbation) in our
simulations. We adopt exponential and von Karman functions as spatial
auto-correlation functions (ACF). In all our simulation results, the
ignorance of the smaller scale heterogeneity leads to underestimation of the
failure pressure around a chamber wall, which relates to dyke initiation.
The magnitude of the velocity perturbation has a larger effect on the
tensile failure at the chamber wall than the difference of the ACF and the
correlation length. The maximum effect on the failure pressure in all our
simulations is about twice larger than that in the homogeneous case. This
indicates that the estimation of the earthquake triggering due to static
stress transfer should take account of the heterogeneity of around hundreds
of meters. |
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