Quarry blasts, underwater explosions, and other dubious seismic events in NE Italy from 1977 to 2013

We have re-examined the phase readings of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) seismometric database, in the years 1977-2013, to isolate explosions and undefined events marked with peculiar codes and clearly tracked in the original full printouts of paper bulletins. Nowadays this tag is not easily available in online metadata, thus leading to erroneous interpretations of the seismicity patterns. We also performed a specific analysis on quarry blasts reported to the Geological Survey of the Trento Autonomous Province, and detected by the network in 2013. More than 4,400 events constitute a new prototypal database of artificial/dubious earthquakes, potentially ascribed to anthropogenic or "induced" events; about 40% of them may be located with the standard procedures of OGS bulletins, even if some solutions are of bad quality. More than 1,000 events, which mainly occurred during the first decades of the monitoring of the north-eastern Alps and reported in actual bulletins, have to be removed from data analysis of natural seismicity, and are easily traceable with the tool given as Supplementary Material.