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A model of the plumes above basaltic fissure eruptions
Author(s) -
Woods Andrew W.
Publication year - 1993
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/93gl01215
Subject(s) - plume , atmosphere (unit) , buoyancy , geology , volcano , atmospheric sciences , latent heat , panache , condensation , moisture , environmental science , meteorology , geochemistry , mechanics , physics
A simple model of the ascent of the volatiles above basaltic fissure eruptions shows that atmospheric moisture may play an important role in injecting volatiles high into the atmosphere. As ambient water vapour is entrained and carried upwards by the plume, it decompresses and some condensation may occur. This causes the release of latent heat which heats up the air and thereby increases the buoyancy of the plume enabling it to ascend several kilometres higher than in a dry atmosphere. The height of such plumes also increases with the mass fraction of fine ash in the fountain. Although very simple, the model predictions are in accord with observations of plume heights during historical eruptions including the 1984 eruption of Mauna Loa.