Rate and distribution of seismic activity are important indicators of the overall state of tectonic stress within a region. In regions characterized by low levels of seismicity, active fault surfaces are rarely visible at the surface, and the analysis of small-magnitude earthquakes at depth may be the most effective way to identify seismic hazard and risk from ambient tectonic activity. Further, studies of local and regional seismicity are also a direct way to examine geophysical and tectonic boundaries, although determining long-term seismicity levels requires good knowledge of the earthquake cycle. A major challenge in monitoring regions with low seismicity levels, therefore, is that long-term recording and/or deployment of sensitive instrumentation is required to provide adequate data.