Relationships between pressure, volatile content and ejecta velocity in three types of volcanic explosion

Wilson, Lionel (1980) Relationships between pressure, volatile content and ejecta velocity in three types of volcanic explosion. Journal of Volcanology and Geothermal Research, 8 (2-4). pp. 297-313. ISSN 0377-0273

Full text not available from this repository.

Abstract

Consideration of the energy equation for a flowing compressible fluid shows that the so-called modified Bernoulli equation, commonly used to relate ejects velocity to pre-explosion pressure in vulcanian-style volcanic explosions, is inadequate in almost all circumstances because of its neglect of the detailed role of volatiles in explosive eruptions. The physical differences between three common types of explosive volcanic activity, typified by plinian, strombolian and vulcanian events, are reviewed and simple mathematical models are proposed for them. The models relate velocities of ejects to initial pressures at the start of an explosive phase and to mass fractions of volatiles (generally taken to be water) in the explosion products. When fitted to observed ejects velocities (or velocities deduced from the dispersal of debris) up to 500 m/s the models predict pressures up to 300 bars — almost always much lower than those deduced in earlier treatments.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Volcanology and Geothermal Research
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900/1906
Subjects:
ID Code:
148999
Deposited By:
Deposited On:
12 Nov 2020 16:40
Refereed?:
Yes
Published?:
Published
Last Modified:
23 Nov 2020 14:56