Characterization of geothermal systems beneath the Hengill volcano in Iceland, using dense nodal networks together with distributed dynamic strain sensing

The Hengill volcanic system in Iceland is of exceptional geological interest and energetic potential. Hengill sits on the mid-Atlantic ridge, on a triple junction, and close to the Icelandic hotspot. It also hosts strong geothermal activity, as apparent at the surface through pools of boiling water scattered across the flanks of the mountain. This geothermal activity has been exploited for electricity production and heating. 

 

While Hengill is of great geological and energetic interest, the geological processes occurring beneath the surface remain only partially understood. Recently, the site has been increasingly instrumented, in particular with large deployments of seismic nodes and with distributed dynamic strain sensing (project DEEPEN and others). These give us an unprecedented opportunity to understand processes at work beneath this exceptional volcanic system and shed light on new geothermal energy reservoirs. 

 

Here we will give an update on ongoing work focused on very local estimates of structure of the geothermal fields, focusing on in situ v_p/v_s ratios within clusters of events and geothermal prospect scale tomography.