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| Titel |
Friction weakening in granular flows deduced from seismic records at the Soufrière Hills Volcano, Montserrat |
| VerfasserIn |
Clara Levy, Anne Mangeney, Fabian Bonilla, Clément Hibert, Eliza Calder, Paddy Smith |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250114318
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| Publikation (Nr.) |
 EGU/EGU2015-14642.pdf |
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| Zusammenfassung |
| Accurate modelling of rockfalls and pyroclastic flows is still an open issue, partly due the
lack of measurements related to the dynamics of such events. Using seismic data from the
Soufrière Hills Volcano and granular flow modelling, we show that the power laws relating
the seismic energy Es to the seismic duration ts and relating the loss of potential energy
δEp to the flow duration tf are very similar (Ei / tiβ with i = s,p), as observed previously
at Piton de la Fournaise, Reunion Island. Observations showing that tf ≈ă ts suggest a
constant ratio Es/δEp ≈ă 10-5. This similarity in the power laws can be obtained only
when the granular flow model uses a friction coefficient that decreases with the
volume involved. Furthermore, with this volume-dependent friction coefficient, the
simulated force applied by the flow to the ground correlates well with the seismic
energy, highlighting the signature of this friction weakening effect in seismic data. |
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