High-rate GNSS positioning for tracing anthropogenic seismic activity

High-rate GNSS observations are usually related to earthquake analysis and structural monitoring. The sampling frequency is in the range of 1-100 Hz and observations are processed in the kinematic mode. Most of the research on short-term dynamic deformations is limited to natural earthquakes with magnitudes exceeding 5 and amplitudes of at least several centimetres up to even meters. The high frequency GNSS stations positions monitoring is particularly important on mining areas due to the mining damages. On the underground mining areas the seismic tremors are regular and there are several hundreds of events annually of magnitude over 2 with maximum magnitudes of 4. As mining tremors are shallow and very frequent, they cause mining damages on infrastructure.

Here, we presented the application of GNSS-seismology to the analysis of anthropogenic seismic activity, where the event magnitude and amplitude of displacements significantly lower. We examined the capacity to detect mining tremors with high-rate GPS observations and demonstrated, for the first time to our knowledge that even subcentimeter ground vibrations caused by anthropogenic activity can be measured this way with a very good agreement with seismological data. One of the most-felt mining shocks in Poland in recent years occurred on January 29, 2019 (12:53:44 UTC) M3.7 event in the area of Legnica-Głogów Copper District and was successfully registered by high-rate GNSS stations co-located with seismic stations. In this mining tremor the peak ground displacements reached 2-16  mm and show the Pearson’s correlation value in range of 0.61 to 0.94 for band-pass filtered horizontal displacements.