English: Overview of seismicity in the Netherlands. The natural seismicity is indicated by grey circles, induced seismicity as recorded by the national KNMI network by blue circles (www.knmi.nl, January 1, 2021). The dark grey lines indicate potentially tectonically active faults; the light grey lines indicate faults in the Permian formations (www.nlog.nl). Oil and gas fields are denoted in red and dark green, respectively; the underground gas storage (UGS) gas fields in orange (www.nlog.nl): 1-Roswinkel, 2-Emmen, 3-Eleveld, 4-Annerveen, 5-Bergermeer, 6-Norg, 7-Grijpskerk, 8-Alkmaar, 9-Castricum Sea; 10-De Hoeve earthquake; 11-Midlaren seismic swarm; 12-post-mining water ingress induced seismicity. Geothermal doublets associated with seismicity are shown as bright green squares, salt domes with large solution mining caverns by cyan triangles, and the shallow solution mining area of Twente-Rijn by a cyan ellipse (www.nlog.nl). CWG: Californië Wijnen Geothermie; CLG: Californië Lipzig Gielen; HL: Heiligerlee salt dome; TWR: Twente-Rijn; ZWD: Zuidwending salt dome.