An Mw based earthquake catalogue for central, northern and northwestern Europe using a hierarchy of magnitude conversions

Data from 25 local catalogues and 30 special studies of earthquakes in central, northern and northwestern Europe have been incorporated into a Databank. The data processing includes discriminating event types, eliminating fake events and duplets and converting different magnitudes and intensities to M-w if this is not given by the original source. The magnitude conversion is a key task of the study and implies establishment of regression equations where no local relations exist. The Catalogue contains tectonic events from the Databank within the area 44degrees N 72degreesN, 25degreesW - 32degreesE and the time period 1300 - 1993. The lower magnitude level for the Catalogue entries is set at M-w = 3.50. The area covered by the different catalogues are associated with polygons. Within each polygon only data from one or a small number of the local catalogues, supplemented by data from special studies, enter the Catalogue. If there are two or more such catalogues or studies providing a solution for an event, a priority algorithm selects one entry for the Catalogue. Then M-w is calculated from one of the magnitude types, or from macroseismic data, given by the selected entry according to another priority scheme. The origin time, location, M-w magnitude and reference are specified for each entry of the Catalogue. So is the epicentral intensity, I-0, if provided by the original source. Following these criteria, a total of about 5,000 earthquakes constitute the Catalogue. Although originally derived for the purpose of seismic hazard calculation within GSHAP, the Catalogue provides a data base for many types of seismicity and seismic hazard studies.