[Hess] Viscous flow of magmas from Unzen volcano, Japan - Implications for magma ascent and emplacement
German Title: Viscous flow of magmas from Unzen volcano, Japan - Implications for magma ascent and emplacement
Abbreviation: 193
Current Status: completed
Main Applicant:Dr. Kai-Uwe Hess
Resources Recipient
Other Persons
Dr. Benoit Cordonnier
Conveyor
Begin:
Conveyor
End:
Conveyor
Duration:
Year: 2005
Description
The lack in understanding the flow behaviour of ascending highly viscous conduit magmas is a major drawback in forecasting explosive volcanic eruptions. Due to the very recent development of a unique high-load, high-temperature deformation apparatus it is now, for the first time, possible to determine the effective non-Newtonian viscosity of rhyolitic multi-phase magmas at strain rates actually occurring prior to and during volcanic eruptions. This opportunity comes when cores from a section of Unzen’s conduit were recently acquired. Taken together, the new technique and the new sample availability provide a unique opportunity to advance the rheological understanding of Unzen. The new data will enable the elaboration of complete volcanic eruption models at Unzen. Such models have important implications for the interpretation of (a) shallow volcanic earthquakes (e.g. low frequency events) and their potential use as indicators for near-future volcanic eruptions, (b) self-sealing mechanisms of the Unzen conduit, and (c) the poorly understood displacement mechanism of Unzen lava lobes, potentially indicative of non-Newtonian flow behaviour.
Related Publications
Cordonnier, B., Hess, K. U., Lavallee, Y., Dingwell, D. B. (2009). "Rheological properties of dome lavas: Case study of Unzen volcano" Earth and Planetary Science Letters 279 p263-272
Vetere, Francesco, Behrens, Harald, Schuessler, Jan A., Holtz, Francois, Misiti, Valeria, Borchers, L. (2008). "Viscosity of andesite melts and its implication for magma mixing prior to Unzen 1991–1995 eruption" Journal of Volcanology and Geothermal Research 275 p208-217
Hess, Kai-Uwe, Cordonnier, Benoit, Lavallée, Yan, Dingwell, Donald B. (2008). "Viscous heating in rhyolite: An in situ experimental determination" Earth and Planetary Science Letters 275 p121-126
K.-U. Hess, B. Cordonnier, Y. Lavallée, D. B. Dingwell (2007). "High-load, high-temperature deformation apparatus for synthetic and natural silicate melts" Review of Scientific Instruments 78 p075102
Lavallée, Yan, Hess, Kai-Uwe, Cordonnier, Benoit, Dingwell, Donald Bruce (2007). "Non-Newtonian rheological law for highly crystalline dome lavas" Geology 35 (9) p843-846