Gaua, a little known volcano in the northern part of Vanuatu archipelago, went through a
long term eruptive activity between September 2009 and July 2010. The eruption started by
a phreatic to phreatomagmatic activity which progressively shifted into a magmatic
discharge. The first eruptive phase involved the hydrothermal system in place. The latter was
likely influenced by seawater seepage, leading to the formation of anhydrite. Magma
involved hereafter this opening phase is of basaltic andesite and basaltic trachyandesite …