Seismic data users and people managing a sesimic network are both interested
in the potentiality of the data, with the difference that the former look at
stability, the second at improvements. In this work we measure the performances
of the Italian Telemetered Seismic Network in 1985-2002 by defining basic
significant parameters and studying their evolution during the years. Then, we
deal with the geological methods used to characterise or to plan a seismic
station deployment in a few cases. Last, we define the gain of the network as
the percentage of located earthquakes with respect to the total recorded
earthquakes. By analysing the distribution of non-located ("missed")
earthquakes, we suggest possible actions to take in order to increase the gain.
Results show that completeness magnitude is 2.4 in the average over the
analysed period, and it can be as low as 2.2 when we consider non-located
earthquakes as well. Parameters such as the distance between an earthquake and
the closest station, and the RMS location decrease with time, reflecting
improvements in the location quality. Methods for geologic and seismological
characterisation of a possible station site also proved to be effective.
Finally, we represent the number of missed earthquakes at each station, showing
that nine stations control more that 50% of all missed earthquakes, and
suggesting areas in Italy where the network might be easily improved.Comment: 17 pages, 1 table, 11 figures. Submitted to Annals of Geophysic