VDH-GT1 is the first well drilled within the framework of the Geoven geothermal project at Vendenheim. The drilling of the well began in June 2017 and reached a final length of 5408 m in March 2018. A second leg at VDH-GT1 was drilled between February and September 2019 and a third between June and August 2020 to 5447 m (4644m TVD). VDH-GT1 will be used as production well. Location of the VDH-GT1 wellhead (in WGS84): Latitude: 48.8970080 Longitude: 7.9387218 Altitude: 134m At the present time, the Geoven project (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/VDHD) is still in development and this description may change.

VDH-GT2 is the second well drilled within the framework of the geothermal project Geoven at Vendenheim. The well was drilled from August 2018 to February 2019 to 5308 m (4417m TVD), and prolongated between November 2019 and February 2020 to 6312m (5011m TVD). VDH-GT2 will be used as injection well. Location of the VDH-GT2 wellhead (in WGS84): Latitude: 48.8970198 Longitude: 7.9386127 Altitude: 134m At the present time, the Geoven project (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/VDHD) is still in development and this description may change.

GNSS data are recorded at REIC station at Vendenheim during VDHD Episode and are provided by the operator Fonroche. The data format is Rinex. The stations are described here (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/GNSS-Stations). See station location (https://cdgp.u-strasbg.fr/Obsnef-Gnss/situation.php) and data availability (https://cdgp.u-strasbg.fr/Obsnef-Gnss/teqc_heatmap.html?REIC).

Seismological signals acquired at Vendenheim during the development phase of the GEOVEN geothermal project. Waveforms from the permanent stations described in VDHD-Surface_network (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/VDHD-Surface_network) are provided for each event from VDHD-Catalogue (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/VDHD-Catalogue), (-30s, +90s). Data are automatically computed at request time

Description of GNSS stations set up around geothermal sites in Alsace. One station must be commissioned by the operator and its data are public. See target station locations and data availability (https://cdgp.u-strasbg.fr/Obsnef-Gnss/situation.php).

Surface seismic network used to study the Geoven Episode. The network consists of stations from several networks: Resif (https://www.resif.fr/) (FDSN code: FR), the French seismic network composed of high gain seismometers and accelerometers, French Accelerometric Network (FDSN code: RA), LRGB network (FDSN code: LE), the German network for Baden-Wuerttemberg, RaspberryShake network (FDSN code: AM) financed by the BCSF-Renass and the LabEx G-eau-thermie Profonde. Public stations from Fonroche network (ECK4 and VDH4) are included in the FR network. Data are automatically computed at request time

Geoven (http://www.geoven.fr) is a geothermal powerplant project led by Fonroche Géothermie now Arverne (https://arverne.earth/). The project is implemented on the site of the Rhenan Ecoparc at Vendenheim, north of Strasbourg. The geothermal powerplant produced 6 MW of electrical energy and 40 MW of thermal energy. To this end, two wells were used to draw the hot water and reinject it at more than 4000 meters deep. The two wells VDH-GT1 (https://cdgp.u-strasbg.fr/geonetwork/srv/eng/catalog.search#/metadata/VDH-GT1) and VDH-GT2 (https://cdgp.u-strasbg.fr/geonetwork/srv/eng/catalog.search#/metadata/VDH-GT2) had been drilled and some tests had been conducted (5 injectivity and productivity cycles between 02/2018 and 11/2019). A first interruption occured after a first period of seismicity (11/2019 – 01/2020, MLv=3.0 max) at Strasbourg and Vendenheim, to allow a third-party scientific expertise. During this period, the well was deepened of 450m to reach 5000m. New tests were authorized starting 10/2020, but were stopped on 28/10/2020 after a new period of seismicity with quake reaching 3.6MLv (04/12/2020). Authority decided on 07/12/2020 to definitely stop the project. Another earthquake of 3.9 ML (https://www.franceseisme.fr/donnees/intensites/2021/210626_0300/Rapport_BCSF-RENASS_2021R1_EVT210626-DPT67.pdf) occured on 26/06/2021. Authorities set up a committee of experts that delivered a first report (https://www.bas-rhin.gouv.fr/Politiques-publiques/Environnement/Geothermie/Rapport-du-comite-d-experts-cree-en-appui-a-l-administration-sur-la-boucle-geothermique-GEOVEN).