COMPARISON OF THE MACROSEISMIC FIELD OF THE 1992 ROERMOND EARTHQUAKE,THE NETHERLANDS, WITH THOSE OF LARGE HISTORICAL EARTHQUAKES IN THE LOWER RHINE EMBAYMENT AND ITS VICINITY

The macroseismic field of the Roermond earthquake of April 13, 1992, h as been compared with those of large historical earthquakes (M(L) grea ter than or equal to 5.5) in the Lower Rhine Embayment and its vicinit y: those of Duren (1755, 1756), Tollhausen (1878), North-Brabant (1932 ) and Euskirchen (1951). The historical earthquakes were reconstructed and analysed mainly on the basis of contemporary historical documents . All investigated earthquakes caused at least moderate damage in thei r epicentral regions. While the earthquakes of Diiren (1756) and Tollh ausen (1878) reached the epicentral intensity VIII, the others produce d only epicentral intensities between VII and VII-VIII. The mean value of the absorption coefficient alpha = 0.002 +/- 0.001 km(-1) was calc ulated from the intensity attenuation curves. The macroseismic focal d epths of the Tollhausen (1878), North-Brabant (1932) and Euskirchen (1 951) earthquakes range from 9 to 8 km, whereas the Diiren (1755, 1756) and Roermond (1992) earthquakes occurred at a depth range from 14 to 18 km. The strongest event in historical time was the Diiren (1756) ea rthquake. Its macroseismically determined local magnitude M(L) = 6.1 w as slightly larger than the local magnitude of the Roermond earthquake M(L) = 5.9.