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A SIMPLE DETERMINISTIC MODEL FOR VOLCANIC ASHFALL DEPOSITION

Published online by Cambridge University Press:  01 January 2008

LENG LENG LIM
Affiliation:
Institute of Information and Mathematical Sciences, Massey University at Albany, Private Bag 102 904, North Shore 0745, New Zealand (email: w.sweatman@massey.ac.nz)
WINSTON L. SWEATMAN*
Affiliation:
Institute of Information and Mathematical Sciences, Massey University at Albany, Private Bag 102 904, North Shore 0745, New Zealand (email: w.sweatman@massey.ac.nz)
ROBERT McKIBBIN
Affiliation:
Institute of Information and Mathematical Sciences, Massey University at Albany, Private Bag 102 904, North Shore 0745, New Zealand (email: w.sweatman@massey.ac.nz)
*
For correspondence; e-mail: w.sweatman@massey.ac.nz
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Abstract

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We describe a simple deterministic model for the dispersion of particulate ash which has been ejected into the atmosphere by a volcanic eruption. In our model the atmosphere is divided into a series of horizontal layers within which the physical parameters involved are constant. This is an effective way to allow for the changing behaviour of the particulate ash and atmospheric flow with height whilst retaining simplicity. From our model we construct an analytical expression for the final deposit which could be incorporated within hazard assessment projections. In particular we show how to allow for variation with height of dispersion (caused by turbulence due to the wind) and settling speed (affected by the agglomeration and fragmentation of particles).

MSC classification

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 2008

References

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