Harvesting geothermal energy from deep underground is playing an ever increasing role in the global energy mix. But as with any human endeavour into the Earth's crust, the extraction of steam and hot water and the subsequent reinjection of cooler fluid back into the ground changes the local field of mechanical stress, which is present everywhere below our feet. Hence accompanying seismic monitoring is a requirement for most geothermal energy projects around the world.
Gaiacode's seismic monitoring equipment was recently installed in the geothermal field of the Roseau Valley on the Caribbean island of Dominica. The field with a planned capacity of 10 MW is currently under development. The goal of the monitoring project is to record micro-seismic activity in the future production area to differentiate between a naturally occuring earthquakes and ones induced by the geothermal activities.
A small array of Thetas
For this purpose, an engineering team of Gaiacode's regional representative Ampere installed a temporary seismic array of 3 THETA broadband velocity sensors, each augmented by an 8-channel, 24-bit TAU digitizer powered by a single solar panel and a small battery.
The data they collect will also be used to study the seismotectonics of this volcanic island. It is planned to integrate the data from these stations with the existing seismic network operated by the Government of the Commonwealth of Dominica.