Some remarks on the term “Active Fault

This paper analyzes the various definitions of the term “active fault” in geologic literature (in a broad sense). This reviewing activity, concentrated on the articles published in the past few decades and on the internet research, has generated the following remarks: i) the term is used to indicate faults which have been subject to movement in recent geologic time or which might move in the present or future; ii) the age limit given to active faults varies depending on the authors; iii) active faults are often associated with strong earthquakes. Identification of active faults can be based on direct and/or indirect methods (historical, geologic, geomorphologic, seismologic, geodetic, geochemical, geophysical and volcanic criteria). In conclusion, at present no universally accepted definition has been agreed upon for “active fault”, nor have the principles and criteria for the identification of active faults and their ranking been worked out.