Integrating gas measurements with other volcanological constraints in order to understand unrest at caldera systems

Abstract:

Periods of unrest at caldera-forming volcanic systems characterized by increased rates of seismicity and deformation are well documented. Some can be linked to eventual eruptive activity, while others are followed by a return to quiescence. Gas emissions from such systems undoubtedly contain important clues to the subsurface behavior causing these periods of unrest. However they are also often dispersed (e.g., through fumaroles and soil degassing) and involve a mixture of magmatic and hydrothermal fluids making these clues more challenging to discern. In this presentation we bring together recent studies from Santorini volcano, Greece, and Aluto volcano, Ethiopia, along with other examples from the literature in order to explore the types of information we can extract from gas measurements and how we can integrate these with other geophysical and geochemical datasets in order to build conceptual models of the subsurface behavior of such systems as exemplified in Figure 1.