British earthquakes

Although the UK is not a strongly seismic region, the study of earthquakes in Britain presents many interesting points. First, British earthquakes are rather well documented throughout history, partly due to the intellectual development and literacy of the country and partly because British earthquakes have always been so newsworthy that even minor events have been recorded in some detail. Secondly, as is rather typical for intraplate areas, the relationship between seismicity and geological structure is unclear. The definitely non-random spatial pattern of British earthquakes is clearly due to something. However, among competing theories as to what that something is, no hypothesis is clearly the best. In this paper, the subject of British seismicity is viewed from several angles. First, the sources that underlie the earthquake catalogue are discussed in order to give a clear indication of the limits on the completeness and accuracy of the data. General statistics for earthquake occurrence in the UK are then presented. This is followed by a description of British seismicity from region to region, with remarks on some key earthquakes of interest. Different hypotheses on the nature of the tectonic or geological control are then reviewed and assessed. Finally, the subject of active faults in the UK is discussed, from the point of view of general seismic hazard assessment.