Chronological evolution of the LDG seismic network and technologies. Blue panel presents the major phases of the LDG seismic network evolution with station and sensor installations. Green panel presents the evolution of number of sensors and number of stations between parentheses, at the network inception (in 1962) and at the end of each decade. Orange panel presents the evolution of type of data. Yellow stars indicate the birth of networks/projects. White triangles correspond to vertical-component short-period station. Blue triangles represent 3-component short-period stations. Red triangles represent 3-component broadband stations. Station names are in bold if they are still running in January 2020. Red names are duplicates since broadband sensors are collocated with short-period sensors, except for SFTF for which the 3-component sensor has been removed and replaced in 2018 by a broadband sensor, alone.