Integrated geophysical studies at ancient Itanos (Greece)

The results of an integrated geophysical survey at the archaeological site of Itanos (Crete) are presented and discussed. At Hellenistic Itanos, which is located near the seashore, the buried ruins are partially under the saline water table. The purpose of this geophysical survey was to map buried relics of buildings, streets and walls of ancient Itanos. In particular, the usefulness of combining conventional geophysical mapping techniques and high resolution imaging methods in delineating shallow targets of archaeological interest at such complex archaeological sites is studied. Magnetic gradient, soil resistance and electromagnetic measurements were taken in grids covering an area of approximately 16,000 m2. Processing of geophysical maps included filtering with the gradient and first derivative operators in the space domain and the upward continuation and Butterworth filters in the wavenumber domain. Emphasis is given to the mathematical description of the processing steps. The integration of the geophysical measurements revealed the existence of a well and three parallel walls verified by excavation. Ground probing radar and electrical tomography sections crossing the parallel walls showed the vertical extent of these features. Ground penetrating radar time slices and 3D electrical tomography depth slices were used for the verification of specific anthropogenic anomalies, which were detected on the geophysical maps. A shallow seismic survey was carried out, in an effort to locate and map the ancient port. The combination of a wide spectrum of geophysical prospecting techniques was successful in delineating the buried relics, enhancing the information context regarding the Hellenistic settlement of Itanos, together with its port and necropolis. The geophysical survey at Itanos demonstrates that the integrated approach is appropriate for archaeological investigations at complex sites like Itanos.