Open AccessModel of a strong volcanic blast and a method of estimating the mass ejected
Author(s) -
Myagkov N.N.
Publication year - 1998
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1046/j.1365-246x.1998.1331460.x
Subject(s) - volcano , mass flux , blast wave , amplitude , geology , shock (circulatory) , seismology , shock wave , caldera , rock mass classification , mechanics , power law , flux (metallurgy) , mass flow , geophysics , physics , materials science , geotechnical engineering , mathematics , medicine , statistics , quantum mechanics , metallurgy
A hydrodynamic model of a strong volcanic blast associated with large (caldera‐forming) ash–gas‐flow eruptions is presented. We show that the mass erupted from a vent influences considerably the damping of the shock wave. If the ejected mass flux is constant, the shock amplitude as a function of distance will decrease slower (in accordance with the inverse 4/3 power law) than that of an atomic explosion (the inverse cube power law). From the modelling, we extract a relation connecting the effective energy of a blast with the mass ejected during the blast phase. The mass released during the largest explosion of the 1883 eruption of Krakatau, and the lateral blast energy at Mount St. Helens on 1980 May 18 are estimated on the basis of the equation obtained.