Twenty years of IDC Reviewed Event Bulletin (REB) statistics using data from a sparse IMS network to one reaching near completion

As of 14 December 2020, almost 90% of the IMS facilities (including radionuclide laboratories) were built and certified, data is transmitted in either real-time or on request from IMS stations to IDC for processing and analyzing. IDC analysts review automatic bulletins generated continuously and release the Reviewed Event Bulletin (REB) on a daily basis since February 2000. We present the statistics of mostly natural seismicity waveform events processed and analyzed over the past 20 years, as the network grew in size and became established. Multiple parameters including magnitude for those events associated with detections from seismic, hydroacoustic and infrasonic stations are analyzed. Techniques and rules related to waveform data analysis and the need to correct the automatic bulletin are discussed. This discussion should be beneficial for analysts work and data processing system optimization.