How geothermal systems work
Prof Thomas Driesner | Institute of Geochemistry and Petrology | ETH Zürich
Abstract: Magma-driven geothermal systems are considered modern analogues of fossil ore-forming hydrothermal processes and are an attractive green energy source. While surface expression such as geysers, steaming ground, mud pools and sinter terraces are well-known to many geoscientists, the intense physical and chemical fluid-rock interactions in the subsurface often aren't. In this presentation I will first review how the competition of heat conduction near the magma and fluid convection in the host rock, the thermodynamic properties of water, and geology conspire to produce a rather small spectrum of possible system styles. This will be followed by an overview of current research to understand the "supercritical" deep parts of geothermal systems with a focus on heat transfer processes at depth and the difficulties to quantitatively understand chemical fluid-rock interaction under such conditions.