Shallow Offshore Geophysical Prospection of Archaeological Sites in Eastern Mediterranean

Abstract

Geophysical prospecting methods have been extensively used to outline buried antiquities in terrestrial sites. Despite the frequent application of these mapping and imaging approaches for the detection of archaeological relics in deep-water marine environments (e.g., shipwrecks), the aforementioned processes have minimal contribution when it comes to understanding the dynamics of the past in coastal and shallow aquatic archaeological sites. This work explores the possibilities of multicomponent geophysical techniques in revealing antiquities that have been submerged in diverse shallow coastal marine environments in the eastern Mediterranean. A group of four sites in Greece (Agioi Theodoroi, Olous, Lambayanna) and Cyprus (Pafos) spanning from prehistory to Roman times were chosen as test sites to validate the efficiency of electrical resistivity tomography, magnetic gradiometry, and ground penetrating radar methods. The comprehensive analysis of the geophysical data completed the picture for the hidden archeological elements in all the sites. The results manifest the significance and the potential of these methods for documenting and understanding the complex archaeological sites encountered in the Mediterranean. In view of climate change and the risks related to future sea level rise and erosion of low-level coastal areas, the results of this work could be integrated in a strategic framework to develop an effective interdisciplinary research model that can be applied to similar shallow water archaeological surveys, thus substantially contributing towards cultural resources management.

Geophysical survey in archaeological context: A review from Cyprus

“…Right: Magnetic susceptibility map resulting from an electromagnetic survey with a CMD Mini‐explorer for a 118 cm coil gauge (drawing a Tabbagh; topographic base R. Touquet). (b) Nea Paphos‐Kato Paphos (Papadopoulos, 2021): 3D isosurface of the resistivity values more than 5.8Ωm showing the extent of the submerged wall structure related to the ancient harbour up to 1.5 m below the seabed. (c) Panayia‐Kofinou (Sarris, 2021): Part of the architectural complex is highlighted in hot colours (red and yellow) in the area of investigations.…”

“…Some positive anomalies have been interpreted as clay pipes used for water management. The ERT method implemented at the port of ‘Kato Paphos’ aimed to investigate underwater archaeological relics dating from Hellenistic to Roman period (Papadopoulos, 2021; Simyrdanis et al, 2017). This survey was able to provide solid evidence on possible building walls that are buried no more than 2 m under the seabed (Figure 3b).…”

“…At coastal sites, harbours constituted a privileged target of the geophysical surveys, although only the sites related from the Iron Age to the Roman period have been investigated. For example, at Amathous, electrical and magnetic survey could locate the extension of the interior basin (Parhas et al, 1979; Thély et al, 2016) and at Nea Paphos (Kato Paphos) underwater ERT detected ancient remains related to the ancient harbour (Papadopoulos, 2021; Simyrdanis et al, 2017) (Figure 3c). Unfortunately, the results of the electrical sounding obtained on the harbour of Amathous (Thély et al, 2016) have not been published.…”

A Semi-Automatic-Based Approach to the Extraction of Underwater Archaeological Features from Ultra-High-Resolution Bathymetric Data: The Case of the Submerged Baia Archaeological Park

“…These can be used (i) from above, as in the case of derived bathymetry from aerial, drone, or satellite images [20][21][22][23][24], or (ii) from operators, boats, and ROVs (Remotely Operated Vehicles), as in the case of the analysis and reconstruction of submerged features using three-dimensional photogrammetry [25][26][27][28]. The active sensors used in RS UCH include the use of electromagnetic and sound waves (sonar), such as (i) single-and multi-beam echosounders, (ii) side-scan sonar, (iii) laser scanners (often combined with optical imaging), (iv) sub bottom profiler, (v) marine magnetometry, and (vi) depth geoelectrics [18,[29][30][31][32][33][34][35][36][37][38][39][40][41][42].…”

Multidisciplinary shallow underwater geophysical prospecting at Delos island

“…The increased attention to coastal zone management contributed to the development and implementation of shallow-water mapping approaches for capturing current environmental and archaeological conditions (Simyrdanis et al 2015(Simyrdanis et al , 2016Papadopoulos 2021). The geophysical survey took place during early September of 2021 and its purpose was to map the extent of the settlement limits through offshore geophysical investigation and to locate possible archaeological relics buried below the sea bottom in two different submerged sites in the northeastern (Stadio) and northwestern (Skhardanas) bays of the island.…”