Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/5125
AuthorsMisiti, V.* 
Vetere, F.* 
Mangiacapra, A.* 
Behrens, H.* 
Cavallo, A.* 
Scarlato, P.* 
Dingwell, D. B.* 
TitleViscosity of high-K basalt from the 5th April 2003 Stromboli paroxysmal explosion
Issue Date2009
Series/Report no./260 (2009)
DOI10.1016/j.chemgeo.2008.12.023
URIhttp://hdl.handle.net/2122/5125
Keywordsviscosity
micropenetration
Falling sphere
Basalt
Stromboli
Silicate melt
Subject Classification04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology 
AbstractThe 5th April 2003 paroxysmal event was the strongest explosion that has occurred at Stromboli in the last 50 years. This event lasted only few minutes and was characterised by two violent explosions, followed by gas and pyroclast emission. In order to constrain models of the dynamics of the paroxystic event the viscosity of anhydrous and hydrous Stromboli high potassium (HK)-basaltic melts have been measured. Viscosity has been investigated in the low viscosity range with the falling sphere method at superliquidus temperatures (1423 to 1673 K) and 0.5 GPa and in the high viscosity range with micropenetration near the glass transition temperature (723 to 1035 K) at atmospheric pressure. Falling sphere experiments were performed in a piston cylinder apparatus with melts whose water content varies from nominally anhydrous (0.02 wt.% H2O) to 4.16 wt.% H2O. The combination of high- and low-viscosity data permits a general description of the viscosity as a function of temperature and water contentusing a modified Tamman–Vogel–Fulcher equation. Using these new viscosity data, an estimation of the flow regime and magma velocity is performed. Our data suggest that the ascent of magma from the 7–8 km deep reservoir to a shallower reservoir located at about 3 km of depth, may occur within minutes. Moreover, we infer a turbulent flow regime. Finally, our estimates of the ascent velocity agree qualitatively with results from petrological studies (e.g. [Bertagnini, A., Métrich, N., Landi, P., Rosi, M., 2003. Stromboli volcano (Aeolian Archipelago, Italy): an openwindowon the deep-feeding system of a steady state basaltic volcano. Journal of Geophysical Research 108, 2336–2350.]), which indicate a turbulent flow regime and rapid ascent velocities such to inhibit volatile-loss-induced crystallization.We conclude that hazard evaluation at Stromboli Island should incorporate the likelihood of very rapid ascent of less-evolved melts from depth.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
ChemicalGeology2009.pdf831.15 kBAdobe PDFView/Open
Show full item record

Page view(s)

212
Last Week
0
Last month
0
checked on Aug 23, 2017

Download(s)

26
checked on Aug 23, 2017

Google ScholarTM

Check

Altmetric