Archaeological prospection of the nearshore and intertidal area using ultra‐high resolution marine acoustic techniques: Results from a test study on the Belgian coast at Ostend‐Raversijde

Abstract

The coastal site of Ostend‐Raversijde in Belgium is known for its archaeological artifacts, mainly from Roman and medieval times. In recent years, detailed geophysical and geotechnical investigations have been carried out here to test the efficiency of these techniques for geoarchaeological prospection of the subtidal and intertidal zone. Very high‐resolution 2D subbottom profiling using a parametric echosounder evidenced a highly complex system of paleogullies and tidal channels, some of which can be linked to the medieval peninsula Testerep and the drowned settlement of Walraversijde. For the first time marine seismic and terrestrial electromagnetic induction (EMI) data were fully integrated in the same intertidal area. The parametric echosounder proved a highly effective tool to map the (partly excavated) peat layers and submerged landscape in high detail, even in extremely shallow water. Using a novel multitransducer parametric echosounder (SES‐2000 Quattro), unique 3D imaging of the peat exploitation pattern was possible with unprecedented detail (submeter level). This sets a new standard for shallow water research and opens important new perspectives for geoarchaeological studies in nearshore areas.

From acoustics to underwater archaeology: Deep investigation of a shallow lake using high‐resolution hydroacoustics—The case of Lake Lednica, Poland

“…Other studies described extensive utilization of SBP for the exploration of shipwrecks (Plets et al 2009;Grøn et al 2015), as well as whole cultural heritage sites (Wunderlich et al 2005). Moreover, recent advancements in SBP technology that use multiple transducers allow 3D models of sediment layers to be created that may provide the detailed identification and description of buried objects (Missiaen et al 2018). However, it should be noted that the 3D seismic data sets are much more difficult to interpret than MBES data sets, especially as a basis for automated classification.…”

The Rise of 3D in Maritime Archaeology

“…Photogrammetry even facilitates 3D survey of the spaces inside large vessels, as demonstrated by the early results of the Thistlegorm Project (2018)-a comprehensive survey in 3D of one of the most well-known and dived wrecks in the world. Other important 3D sensing techniques for the marine environment also emerged around the same time, including lidar bathymetry (Doneus et al 2013(Doneus et al , 2015, 3D sub-bottom profilers (Gutowski et al 2015;Missiaen et al 2018;Plets et al 2008;Vardy et al 2008) and Electrical Resistivity Tomography (ERT) (Simyrdanis et al 2016;Passaro et al 2009;Ranieri et al 2010;Simyrdanis et al 2015Simyrdanis et al , 2018. These are enor-mously important due to their ability to non-invasively recover 3D data from shallow water (lidar bathymetry) sites and from below the seabed (sub-bottom profilers and ERT), but due to cost and availability are not nearly as widely used as multibeam and photogrammetry.…”

“…Perhaps the earliest example is by Quinn et al (1997) who published the geophysical evidence for paleoscour marks at the Mary Rose site. Subsequent technical evolution of 3D sub-bottom profiling systems, include a 3D Chirp reconstruction of the wreck of Grace Dieu (Plets et al 2008(Plets et al , 2009 and Missiaen et al's (2018) parametric 3D imaging of submerged complex peat exploitation patterns. Two further ground-breaking studies on this subject appear in this volume.…”

Quantifying Depth of Burial and Composition of Shallow Buried Archaeological Material: Integrated Sub-bottom Profiling and 3D Survey Approaches

“…More recently Innomar Technologie GmbH introduced a multi-transducer sub-bottom profiler to capture very high data density in shallow waters (SES-2000 quattro) which can be subsequently viewed in 3D using grid-ding and visualization software. Missiaen et al (2017) conducted 3D seismic surveys using the SES-2000 quattro across shallow intertidal areas at the coastal site of Ostend-Raversijde, Belgium. This complemented the previous 2D parametric surveys on this site and provided an image of the complex peat exploitation patterns, the features of which matched with old aerial photographs.…”