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Open-File Report 00-209

A numerical program for steady-state flow of magma-gas mixtures through vertical eruptive conduits

By Larry G. Mastin and Mark S Ghiorso

Thumbnail of and link to report PDF (870 KB)Summary

This report presents a model that calculates flow properties (pressure, vesicularity, and some 35 other parameters) as a function of vertical position within a volcanic conduit during a steady-state eruption. The model idealizes the magma-gas mixture as a single homogeneous fluid and calculates gas exsolution under the assumption of equilibrium conditions. These are the same assumptions on which classic conduit models (e.g. Wilson and Head, 1981) have been based. They are most appropriate when applied to eruptions of rapidly ascending magma (basaltic lava-fountain eruptions, and Plinian or sub-Plinian eruptions of intermediate or silicic magmas) that contains abundant nucleation sites (microlites, for example) for bubble growth.

First posted May 08, 2008

Reposted November 15, 2013

For additional information:
Contact CVO 
Volcano Science Center, Cascades Volcano Observatory 
U.S. Geological Survey 
1300 SE Cardinal Court, Building 10, Suite 100 
Vancouver, WA 98683-9589

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Suggested citation:

Mastin, L. G., and Ghiorso, M. S., 2000, A numerical program for steady-state flow of magma-gas mixtures through vertical eruptive conduits (vers. 1.05b, April 2008):  U.S. Geological Survey Open-File Report 00-209, 61 pp, https://pubs.usgs.gov/of/2000/0209/.


Contents

Introduction

Model overview

Model assumptions and limitations

Model setup

First-Order Testing the model

Using the Windows-based system

Running the model from the command line

Closing comments

Accessibility FOIA Privacy Policies and Notices

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