Aquisition infrastructure and methodology

In cooperation with TNO and KNMI, an acquisition infrastructure for seismic monitoring has been built in the northern part of the Netherlands (Lofar). It has created the possibility to validate our interferometric methods and it is used for validating active-seismic monitoring methods. On the technological side, it has generated new concepts of how to set up such large-scale networks. In the coming years the Lofar network will amongst others be used for a program on induced seismicity, to monitor gas-induced earthquakes as occurring in that region.

Generating low frequencies (typically down to 1.5 or 2 Hz) cannot be done by standard seismic vibrators and therefore a new technology has been used to make a vibrator that can generate them, using so-called Linear Synchronous Motors. This new vibrator is not only being used for velocity estimation, imaging and monitoring, but also for characterizing structure stabilities under earthquakes, such as occurring in the northern part of the Netherlands.  

New type of vibrator based on Linear Synchronous Motors: the lower the frequency, the better it works.