Figure 1.

Characteristics of seismicity at The Geysers geothermal area. The epicentral distribution of the earthquakes is represented with dots and circles: light grey dots indicate earthquakes with $M_W$ less than 3, and grey circle earthquakes with $M_W$ larger or equal to 3. The larger events with $M_W$ greater than 3.9 are marked with red dots. The upper inset shows the location map of the Geyser geothermal area. The lower inset shows the magnitude temporal distribution, the symbols are coloured according to the depth. Black diamonds and triangles represent the location of seismic stations. Reverse empty triangles represent the wells’ position. The figures are generated by using the version 5 of Generic Mapping Tools (https://www.generic-mapping-tools.org/).