Archaeoseismic trace mapping and raster analyses for risk reduction in archaeological sites.

Nowadays seismic risk in archaeological sites is under close scrutiny. National and international institutions are in fact working on the development of guidelines and rules concerning the fruition, under safety conditions, of ancient and historical Architecture; moreover, the scientific community is working on establishing specific policies addressing conservation and restoration interventions in seismic risk areas. Hierapolis in Phrygia is one of the most important Roman cities in western Anatolia; indeed, the history of the city, founded in the 3rd century BC, has been characterized by destructive seismic events, which have also marked the main phases of its urban development. An important Italian Archaeological Mission is active here (under the direction of Politecnico di Torino until 2000, and now headed by prof. D’Andria from the University of Lecce). The Hierapolis area has been subjected to precise and in-depth studies concerning ancient seismology; the tectonic characters of the region have been displayed and, based on the comparison between ancient historical sources and the archaeological evidence, a catalogue of the most relevant in magnitude earthquakes has been compiled. [E. Altunel, P.L. Hancock, 1996; E. Altunel, 2000; Guidoboni et alii 1994, G.E Bean, 1980; T. Ritti, 1987; D’Andria 1987.] Recently, the cooperation between researchers from Politecnico and specialists in Archaeology lead to developing a large scale (1:1000) archaeological site map, based on a topographical database. Jointly with this urban scale representation, numerous metric surveys at archaeological and architectural scale of the principal monuments of the city have been accomplished; some of them were expressly contrived in order to point out to damage relative to ancient destructive earthquakes. The availability of this large set of data, different by nature, scale and accuracy, but concerning the same issue, allows for the opportunity to profit on the potential of mapping and on the analyses abilities of GIS tools, to compare information.