Water-stimulation of the boreholes is proceeding well and has been going on now for a week at the Otaniemi site, where geothermal heat experts are leading water to a 6.4-km deep hole and monitoring with project’s underground geophones the micro-vibrations and the water flow they induce in the rock.
The geophones in the bedrock in the Helsinki Metropolitan area, discovered this morning 1,59 magnitude micro-vibration in the depth of the bedrock. The effects of this magnitude of micro-vibration is hardly noticeable at the ground level and do not cause a risk to humans or damage to structures. The Institute of Seismology has monitored 1.2 magnitude micro-vibration. The differences in the measurement result is due to differences in measurement methods and equipment. The St1 equipment is tuned to detect water movements as accurately as possible.
Inducing micro-vibration with stimulation is a key part of constructing a geothermal heat plant, as only it can be used to investigate the water flow required for heat production in the deep bedrock. St1 implements the stimulation in a highly controlled manner and according to the measures required by the authorities. We communicate all micro-vibrations exceeding 1.2 magnitudes at our project website.
Geophone measurement results as well as up to date information can be monitored in real time online www.st1.eu/geothermal-heat