This book includes innovative gas-geothermometers and geobarometers,
which are urgently needed to estimate the increasingly higher
temperatures and pressures present at depth below the Solfatara volcano,
owing to its on-going unrest. Therefore, in this book, new gas
geoindicators, applicable up to ca. 1000°C and 3 kbar, have been
implemented and applied to Solfatara fluids. The innovations of this
book include: methane, having a sluggish behavior, was treated
separately from fast-reacting carbon monoxide; deviations from the ideal
gas behavior were considered; the effects of reaction kinetics were
taken into account. This was possible because a dataset including many
geochemical parameters and extending from 1983 to 2020 with a good
sampling frequency is available for Solfatara, making it a case history
probably unique worldwide. Nevertheless, the gas geoindicators described
in this book can be applied to other similar systems. Thus, this book is
of interest to many scientists studying gas geochemistry,
geothermometry, and geobarometry for volcanic surveillance and the
mitigation of the volcanic risk.