Marine geophysical methods for archaeological investigation of volcanic and bradyseismic areas

Abstract

The aim of this work was to test several geophysical methods for the identification and study of submerged prehistorical coastlines and archaeological sites. This research program was carried out in collaboration with the <<Osservatorio Vesuviano>> in the Gulf of Pozzuoli and dealt in particular with the bathymetric strips extending from - 5 m to - 50 m Within these strips we identified the coastline dating from the Rornan period. former beach boundaries associated with the vertical movements of the earth's surface caused by seismic-volcanic activity, and the variations in sea level following the climactic changes throughout the last 15000 years. The UNIBOOM system was used for this part of the programme, perinittiilg the identification of several coastlines and submerged beaches lying at different levels. The use of a modern Side Scan Sonar - for the morphological invesdgation of the sea bed - in a zone which had been the object of numerous archaeological surveys in the past, permitted previously unknown structures near the Lacuus Baianus to be identified. Other features worth pointing out include the operating speed of the system (15000 m'lfirst minute approx) and its observation capacity in cloudy waters compared to visible radiation, as well as its ability to penetrate thin layers of mud which generally impede direct underwater observation.