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The data from the Bulletin of the International Seismological Centre (ISC) have always been and still remain in demand for a wide range of studies in Geosciences. The unique features of the Bulletin include long-term coverage (1904-present), the most comprehensive set of included seismic data from the majority of permanent seismic networks at any given time in the history of instrumental recording (currently ~ 150) and homogeneity of the data and their representation. In order to preserve this homogeneity, the ISC has followed its own standard seismic event processing procedures that have not substantially changed until the early 2000s. Several considerable and necessary advancements in the ISC data collection and seismic event location procedures have created a need to rebuild the data for preceding years in line with the new procedures. Thus was set up a project to rebuild the ISC Bulletin for the period from the beginning of the ISC data till the end of data year 2010. The project is known as the Rebuild of the ISC Bulletin. From data month of January 2011, the ISC data have already been processed with the fully tested and established new procedures and do not require an alteration. It was inconceivable even to think about such a project for many tens of years, but great advances in computer power and increased support by the ISC MemberInstitutions and Sponsors have given us a chance to perform this project. Having obtained a lot of experience on the way, we believe that within a few years the entire period of the ISC data will be reprocessed and extended for the entire period of instrumental seismological recordings from 1904 till present. The purpose of this article is to describe the work on reprocessing the ISC Bulletin data under the Rebuild project. We also announce the release of the rebuilt ISC Bulletin for the period 1964-1979 with all seismic events reprocessed and relocated in line with the modern ISC procedures, ~ 68,000 new events, 255 new stations, ~ 815,000 new seismic phases, more robust and reliable mb and M S magnitude evaluations and the addition of ~ 2700 new M S magnitudes.

The Bulletin of the International Seismological Centre (ISC) remains in demand for a wide range of geophysical studies. Users of the ISC Bulletin benefit from its long-term coverage, the most comprehensive set of measurements from the majority of permanent seismic stations and networks, and homogeneity of included parameters of earthquakes and other seismic events worldwide. Despite a reasonably conservative approach in preserving the operational procedures, changes are inevitable in order to achieve the best possible accuracy of published earthquake parameters. The last fundamental change in procedures has fully affected the data for years 2011 and beyond (Bondár and Storchak in Geophys J Int 186: 1220-1244, 2011). This is why it was decided to rebuild the earlier part (1964–2010) of the ISC Bulletin to achieve compatibility in earthquake hypocentres and magnitudes through its entire period. The first article on this project (Storchak et al. in Geosci Lett 4: 32, 2017) covered the period from 1964 to 1979, as it was publicly released. This article covers the remaining period from 1980 to 2010 with all seismic events re-processed and re-located in line with the modern ISC procedures, with ~ 489,000 new events, ~ 2600 new stations, ~15.5 million new seismic arrivals, and more robust and reliable mb and MS magnitude evaluations. We give statistics of departures in epicentre location and depth between the original and rebuilt ISC hypocentres. We also provide a summary for the entire rebuilt period (1964–2010). We give a brief account of events deleted from and added to the Bulletin, based on additional reports from permanent and temporary seismic deployments. We explain that newly re-computed (rebuilt) mb is on average larger that the original mb by 0.05 unit of magnitude. The rebuilt MS is only 0.01 unit larger that its predecessor. We announce that the entire reviewed part of the ISC Bulletin (1964–2017) is now based on the same velocity model, ak135, and the same earthquake location and magnitude computation procedures. Finally, we provide advice on how to obtain the original ISC Bulletin data, where necessary.

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