EREBUS

Résumé

Erebus is well-known for its sustained lava lake, alkaline intraplate
character, and, of course, its southerly latitude. The volcano
displays two kinds of behaviour: (i) lava lake, and (ii) lava lake
plus intermittent Strombolian eruptions. Thanks to a combination of
melt inclusion modelling (by Roberto Moretti) and high time resolution
gas measurements and thermal imaging at the crater, we are building a
new conceptual model for the plumbing system of Erebus – from the deep
basanite supply, through intermediate magmas, to the evolved phonolite
lake. On one level, the behaviour is simple, stable, sustained but the
magma differentiation, mantle-to-surface degassing, conduit geometry,
and the moderate viscosity of the phonolitic magma superimpose
fascinating complexity on the long-lived lava lake. I will highlight
what we have been doing on Erebus (principally using remote sensing
techniques) over the past 5 years or so, and summarise where we have
reached in our understanding of the volcano’s behaviour. I will touch
briefly on the atmospheric chemistry of the Erebus plume, including
its effect on ozone.