A note on blast-monitor and conventional seismic network recordings of moderate-sized earthquakes in the Central United States

Since the mid 1980s small and moderate-sized earthquakes in the Ohio and Wabash River valleys of the central United States (CUS) have been digitally recorded by seismographs, called blast monitors, deployed to detect and characterize vibrations from explosions associated with regional mining and quarrying. Because there were relatively few conventional networked strong-motion and broadband instruments for this area between 1980 and the early 2000s, the more than 200 collected observations have provided a widespread source of digital earthquake ground motions. Additional deployment of networked instrumentation during the last decade and their numerous recordings of the 18 April 2008 Mt. Carmel Illinois earthquake sequence have provided the first effective means for comparing free-field blast-monitor and conventional network ground motion observations. The peak ground motion characteristics for both data sets relative to a common predictive relationship are similar, suggesting that blast monitor observations compliment conventional network data for small and moderate-sized (M <5:5) events in the CUS.