The International Seismological Centre (ISC), funded mostly by contributions from 55 national institutes in 47 countries, has produced the most comprehensive global seismicity bulletin for more than 30 years. Seismologists use ISC data to investigate the Earth's internal structure, analyze seismic hazards, and evaluate tectonic models. They depend on a consistently high level of qualityin the bulletin from year to year but, due to the growing volume of data, change may be coming to the ISC.
Thanks to an increasing number of regional and national networks around the world/the ISC bulletin has grown to cover more than 60,000 events annually. But even as the bulletin tripled in size over the last 20 years, budgetary restrictions have prevented growth of the ISC staff or significant development of its computer resources. With publication of the bulletin beginning to experience delays, the strain is starting to show.