Abstract

Seismology and palaeoseismology have a mutual goal in the assessment of seismic hazards. They are both needed to make the assessments meaningful. There are, however, some dialectics between the two disciplines. The south Scandinavian situation is highlighted with respect to the questions of seismic continuity versus discontinuity, coincidence versus verification and the application of multiple parameters in palaeoseismology. It is concluded that millennial-scale seismic records are characterized by discontinuities in seismic activity. In southern Scandinavia there is a clear successive increase in the maximum earthquake moment magnitudes back in time from <4.5 today, via >6 to c. 7 in the Late Holocene to c. 8 to >8 during times of deglaciation. This paper presents a rather philosophical view of the dialectics and interactions between instrumental seismology and geologically based palaeoseismology. This means that it is strongly based on the author's own material in the field and his mind because it represents his own experiences over a long period of active work in palaeoseismology and neotectonics.