St1's geothermal project’s stimulation stage has started in Otaniemi, Espoo. The pumping of water down to a 6,4-kilometer-deep borehole has started in accordance with the plan. The stimulation stage is an essential step in the geothermal project and aims to study how water can flow between the two boreholes through rock fissures at the depth of more than six kilometres underground.
The stimulus-induced micro-vibration at the fissures in the rock is monitored by a broad geophonic network installed on the bedrock in the metropolitan area.
Stimulation is divided into five sections and lasts for a total of 30 days. Geofones' measurement results can be monitored in real time online: www.st1.eu/geothermal-heat