The Hot Dry Rock (HDR) site of Soultz-sous-Forêts in Alsace was chosen in 1986 for scientific investigations. During the first phase of the project (1987-1988), a first borehole GPK1 (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/SSF-GPK1) was drilled. It reached a final depth of 2000 m and various investigations were undertaken during that period. In December 1988, an injection test was made at the bottom zone of this borehole with a relatively low flow rate of 3.3 l/s for a period of three days. Induced seismicity recorded was detected by 3-axis geophone probes deployed in three old recovered oil wells at depth rang…

uggugu