Ground-Truth Database for Regional Seismic Identification Research,

The Ground-Truth Database GTDB provides a subset of the events necessary for seismic discrimination research accurately located events with regional waveforms and known source type. While it is true that digital waveform data are easily exchanged through the Internet, the data are significantly more useful to discrimination research when event windows have been extracted from the continuous data and when additional documented information, such as source type, is associated with each event. Such a database, readily available and in a consistent format, minimizes the extensive efforts of data collection, organization, review and verification that are often the first phase of new research projects. Having this type of information is essential for development and assessment of algorithms for seismic event location and classification without having to assume the characteristics of the very events under investigation. The Ground-Truth Database was introduced at the 14th Annual Seismic Research Symposium Grant and Coyne, 1992 under an ARPA contract. By the time of the 15th Annual Seismic Research Symposium, 288 known events comprising 10 datasets in Western Europe and Scandinavia were available to the research community Grant et al., 1993b. A large part of the success of the CSS GTDB was due to researchers who wanted to make data available to others by providing the results of their own data-collection efforts to the GTDB. Two general methods were used to build these datasets. If the target events were the subject of a research study where ground-truth was published for a list of events, then we collected the associated waveforms. Another approach was to look at the regional seismicity bulletins produced by the IMS Bache et al., 1990 and seek macroseismic information for significant clusters of events.