Geothermal energy is a relatively clean energy source that is estimated to have a large global potential. However, it currently provides humankind with but a small portion of its energy needs. Technologies are rapidly developing to store heat in the subsurface, heat pumps make it possible to extract useful heat at relatively low temperatures and the drilling technology exists to access geothermal heat at great depth. In volcanic areas, this heat is often accessible at much lesser depth and this is where most of the world’s geothermal electricity production takes place.
To develop this attractive energy source further sets a number of geoscientific challenges, including developing exploration methods capable of sufficient resolution at depth, understanding the permeability structure of the crust, improving heat-flow mapping in the near surface and understanding induced seismicity associated with hydrofracturing to create permeability or with replenishing geothermal aquifers with waste water after use.
The geophysics program is involved in a number of projects relating to geothermal energy, mostly on volcanic Iceland. We work with development of seismic exploration methods to map structure in the uppermost crust using local microearthquakes, application of advanced signal processing methods to locate sources of geothermal tremor and use seismic noise sources for structural imaging. We also work with electromagnetic imaging methods and problems of joint geophysical inversion, combining information from multiple imaging methods (e.g. seismic and electromagnetic). Furthermore, we work with detailed mapping methods of faults in the crust by detailed locations of microearthquakes, which helps characterizing permeability in the crust, and detailed studies of induced seismicity to better understand its mechanism.