Friction weakening in granular flows deduced from seismic records at the Soufrière Hills Volcano, Montserrat

Abstract : Accurate modeling of rockfalls and pyroclastic flows is still an open issue, partly due to a lack of measurements related to their dynamics. Using seismic data from the Soufrière Hills Volcano, Montserrat, and granular flow modeling, 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, like the power laws observed at Piton de la Fournaise, Reunion Island. Observations showing that tf≃ts suggest a constant ratio Es/ΔEp≃10−5. This similarity in these two power laws can be obtained only when the granular flow model uses a friction coefficient that decreases with the volume transported. 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.
Type de document :
Article dans une revue
Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2015, 120 (11), 〈10.1002/2015JB012151〉
Liste complète des métadonnées

https://hal-brgm.archives-ouvertes.fr/hal-01357296
Contributeur : Anne-Marie Pouget <>
Soumis le : lundi 29 août 2016 - 15:49:43
Dernière modification le : mercredi 11 avril 2018 - 12:10:02

Identifiants

Collections

Citation

Clara Levy, Anne Mangeney, Fabian Bonilla, Clément Hibert, Eliza S. Calder, et al.. Friction weakening in granular flows deduced from seismic records at the Soufrière Hills Volcano, Montserrat. Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2015, 120 (11), 〈10.1002/2015JB012151〉. 〈hal-01357296〉

Partager

Métriques

Consultations de la notice

84