Earthquake effects on the environment: from historical descriptions to thematic cartography

Abstract

In the Catalogue of Strong Italian Earthquakes, all testimonies relating to effects on the environment have been systematically analysed, geo-referenced and filed. This complex work of research and organisation has been conducted according to two main perspectives: the historical and the geological point of view. As regards the historical point of view, on the one hand the elements of complexity have been highlighted relative to data which, particularly before the seventeenth century, had been produced within cognitive and cultural contexts which are now extremely remote and beyond naturalistic logic. On the other hand, from the seventeenth century, the growing attention of the cultural élite of the era towards environmental phenomena (now being seen within a naturalistic perspective), favoured the gradual enhancement of the corpus of information, also as regards the quality of the data. 2053 effects of earthquakes on the environment are listed in the CFTI3, classified into five categories which are in turn divided into other descriptive typologies. Many examples are also provided with the purpose of outlining the specific problems concerning the available data. As regards the geological point of view, the effects described in historical sources may be divided into two categories: the effects related to shaking, and the effects which may be due directly to the seismogenic source, generally with less territorial impact but of considerable scientific interest. Reference is also made to the various attempts to codify the environmental effects of earthquakes within the traditional macroseismic scales, although it is acknowledged that this operation is fraught with ambiguities. Prospective users of the CFTI3 are encouraged to take advantage of the availability of the original testimonies to develop their own interpretations of the phenomena described.