A Lot of Hot Air: volcanic degassing and its impact on our environment

Professor Marie Edmonds FRS

Volcanoes are hazardous and beautiful manifestations of the dynamic processes that have shaped our planet. Volcanoes impact our environment in numerous ways. Over geological time volcanic activity has resurfaced the Earth and provided life with a terrestrial substrate upon which to proliferate. Volcanic degassing has shaped our secondary atmosphere and as part of the process of plate tectonics, maintained just the right amount of water and carbon dioxide at the surface to produce a stable and equitable climate. Magma in the subsurface in volcanic environments today gives Society geothermal energy. The fluids degassed from magmas in the plumbing systems of volcanoes give rise to hydrothermal ore deposits, the source of much of our copper and other metals, critical to the energy transition. In this lecture I will describe the nature and importance of magma degassing for our atmosphere and oceans, as a source of both pollutants and nutrients, and in the formation of mineral deposits. I will describe my own research in carrying out measurements of volcanic gases (using a range of spectroscopic methods, from the ground and using drones), and analysis of erupted lavas, to understand the chemistry and physics of volcanic outgassing and its role in sustaining our planetary environment.