acoustic archeology

Due to the rise in sea-level over the past 20 000 years, numerous archeological sites close to existing coastlines, are now submerged. Detecting these sites, by non-invasive means, is important for world cultural heritage. Just as we did for biodiversity monitoring of whales, acoustic exploration is indicated here. In particular, since flint relics often characterize the presence of pre-historic sites in particular, we can exploit the fact that they have very pronounced acoustic resonance signatures to probe coastal waters. This is very close to what we did in the sediment mapping twin, and the principles and methods used for the modeling are similar.

Actual flints were digitized and their geometry transferred by CAD software to a mesher, and then collections of flints were embedded in a faithful representation of the coastal underwater sediments.

This is a 2D cross-section of the mesh of the complete environmemt, showing the different layers, the flint collections in the cultural layers, the acoustic source (circle) and one of the hydrophones (diamond).

Time-domain simulations of the acouric-elastic wave equation were performed with the SPECFEM code an then frequency spectra were computed. By taking the difference between simulations with and without flints, we easily detect their presence as well as their resonances. This is illlustrated in the figures below.

Full details of this twin and simulation results can be found in our paper (Hermand et al., 2011) and the IEEE/Oceans presentation.

References

1. IEEE

   Modelling flint acoustics for detection of submerged Stone Age sites

   Hermand, Jean-Pierre, Grøn, Ole, Asch, Mark, and Ren, Qunyan

   In OCEANS 2011 2011

   Bib

   @inproceedings{Hermand2011,
     author = {Hermand, Jean-Pierre and Gr{\o}n, Ole and Asch, Mark and Ren, Qunyan},
     title = {Modelling flint acoustics for detection of submerged Stone Age sites},
     booktitle = {OCEANS 2011},
     year = {2011},
     pages = {1--9},
     organization = {IEEE},
     abbr = {IEEE},
     bibtex_show = {true}
   }