SurtseyanBombs_as_published_rspa.2021.pdf (1.25 MB)
Download file

A theoretical model of Surtseyan bomb fragmentation

Download (1.25 MB)
journal contribution
posted on 25.11.2021, 04:13 by E Greenbank, Mark McGuinnessMark McGuinness, Christopher SchipperChristopher Schipper
Surtseyan eruptions are an important class of mostly basaltic volcanic eruptions first identified in the 1960s, where erupting magma at an air-water interface interacts with large quantities of slurry, a mixture of previously ejected tephra that re-enters the crater together with water. During a Surtseyan eruption, hot magma bombs are ejected that initially contain pockets of slurry. Despite the formation of steam and anticipated subsequent high pressures inside these bombs, many survive to land without exploding. We seek to explain this by building and solving a simplified spherical mathematical model that describes the coupled evolution of pressure and temperature due to the flashing of liquid to vapour within a Surtseyan bomb while it is in flight. Analysis of the model provides a criterion for fragmentation of the bomb due to steam pressure build-up, and predicts that if diffusive steam flow through the porous bomb is sufficiently rapid the bomb will survive the flight intact. This criterion explicitly relates fragmentation to bomb properties, and describes how a Surtseyan bomb can survive in flight despite containing flashing liquid water, contributing to an ongoing discussion in volcanology about the origins of the inclusions found inside bombs.

History

Preferred citation

Greenbank, E., McGuinness, M. J. & Schipper, C. I. (2021). A theoretical model of Surtseyan bomb fragmentation. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 477(2253), 20210166-20210166. https://doi.org/10.1098/rspa.2021.0166

Journal title

Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences

Volume

477

Issue

2253

Publication date

01/01/2021

Pagination

20210166-20210166

Publisher

The Royal Society

Publication status

Published

Online publication date

08/09/2021

ISSN

1364-5021

eISSN

1471-2946

Language

en

Usage metrics

Read the peer-reviewed publication

Categories

Exports