Two additional mobile stations complement our seismograph network.
All stations have digital recording.
Table 1 gives an overview over the stations and its instrumentation operating since 1904 in the Netherlands. Seismograph recordings and digital data have been archived and are available for research. In the Netherlands seismic activity is mainly observed in and around the Roer Valley Graben in the southeastern part of the country. The borehole seismometer strings and the accelerometers are presently mainly used for monitoring this induced seismicity. In response to your request with regard to the earthquake catalog and arrival times observations, the following.