To what degree can historical seismicity records assist in seismic microzonation?

It is well known that historical data of seismic effects in urban areas can be useful in seismic microzonation, but we must consider how to make the most of available documentary sources and assess to what degree historical information can help us. From this starting point, this paper deals in a more objective manner with the potential contribution of macroseismic site data, suggesting the compilation of an ad hoc questionnaire. In this way, the two main aims of this paper can be achieved: to make the most of available documentary sources, and to quantify the usefulness of macroseismic information for microzonation analysis via a 'Site Normalised Utility and Reliability Parameter' (SNURP). This second aim resolves, for example, the question of priority in resource allocation for microzonation site surveys. On the whole, the proposed approach will provide an easily used tool to deal with historical accounts, especially for professionals in the engineering geology field.