For many years, the two subjects of (1) postglacial rebound and its potential for generating earthquakes and (2) the seismicity of passive continental ml!rgins have been of interest and concern to earth scientists on both sides of the North Atlantic. New data and theoretical interpretations have given rise to vigorous discussions on how much the two phenomena inter-relate and whether a significant controlling factor on seismicity in northeastern North America and Scandinavia is the crustal uplift that has been occurring since the latest ice age. The lack of a good understanding of these phenomena presented a particular problem for engineering seismologists attempting to prepare accurate seismic