Published:January 01, 2017
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.
Figures & Tables
Seismicity, Fault Rupture and Earthquake Hazards in Slowly Deforming Regions
Palaeoseismic records and seismological data from continental interiors increasingly show that these areas of slow strain accumulation are more subject to seismic and associated natural hazards than previously thought. Moreover, some of our instincts developed for assessing hazards at plate boundaries might not apply here. Hence assessing hazards and drawing implications for the future is challenging, and how well it can be done heavily depends on the ability to assess the spatiotemporal distribution of past large earthquakes. This book explores some key issues in understanding hazards in slowly deforming areas. Examples include classic intraplate regions, such as Central and Northern Europe, Mongolia, Inner Mongolia, Australia, and North and South America, and regions of widely distributed strain, such as the Tien Shan Mountains in Central Asia. The papers in this volume are grouped into two sections. The first section deals with instrumental and historical earthquake data and associated hazard assessments. The second section covers methods from structural geology, palaeoseismology and tectonic geomorphology, and incorporates field evidence.