Local earthquake monitoring with a low-cost seismic network: a case study in Nepal

Seismic monitoring matters both for research and for populations living in areas of seismic hazard; however, it comes with a cost that is not fully affordable for developing countries. Compared to classical approaches with very quiet sites and high-quality instrumentation, it is therefore worth investigating low-cost seismic networks and how well they perform at detecting and characterizing seismicity. We analyze 1 year of seismic data from an educational seismology network in Nepal, create our own earthquake catalog, and compare it to the publicly available national observatory catalog. We find that despite the noisier seismic station sites, the overall results are comparable and all the main features relevant for seismicity are found. We present quantitative analyses of locations, magnitudes and their frequency distribution in our catalog, as well as differences with the observatory catalog. Differences between the two catalogs primarily stem from the respective network geometries and their coverage, as well as daytime noise level differences. We conclude that if properly planned and installed, low-cost seismic networks are a viable, feasible and significant complement to monitor seismic activity.