Abstract. Geothermal systems in the Hengill volcanic area, SW
Iceland, started to be exploited for electrical power and heat production
since the late 1960s. Today the two largest operating geothermal power
plants are located at Nesjavellir and Hellisheiði. This area is a
complex tectonic and geothermal site, located at the triple junction between
the Reykjanes Peninsula (RP), the Western Volcanic Zone (WVZ), and the South
Iceland Seismic Zone (SISZ). The region is seismically highly active with
several thousand earthquakes located yearly. The origin of such earthquakes
may be either natural or anthropogenic. The analysis of microseismicity can
provide useful information on natural active processes in tectonic,
geothermal and volcanic environments as well as on physical mechanisms
governing induced events. Here, we investigate the microseismicity occurring
in Hengill area, using a very dense broadband seismic monitoring network
deployed in Hellisheiði since November 2018, and apply sophisticated
full-waveform based method for detection and location. Improved locations
and first characterization indicate that it is possible to identify
different types of microseismic clusters, which are associated with either
production/injection or the tectonic setting of the geothermal area.
Cap rock efficiency of geothermal systems in fold-and-thrust belts: Evidence from paleo-thermal and structural analyses in Rosario de La Frontera geothermal area (NW Argentina)
