The development of an acoustic system for costeffective
mapping of submerged Stone Age sites located on, and
embedded in, the sea floor, reported briefly at the 2nd RIO
Acoustics Symposium (Grøn et al. 2016), has progressed
significantly since then. A number of experiments and survey
results now demonstrate that it is possible to obtain clear and
significant acoustic responses from flint tools and debitage1
produced by humans, whereas naturally-cracked pieces of flint of
similar shapes and dimensions do not produce equivalent
responses. It has also been demonstrated that debitage responds
acoustically even when embedded within sea-floor sediments. So
far, responses have been obtained from the cultural layers of
Stone Age settlements containing large amounts debitage covered
by at least one metre of sediment. It is now important to develop
the method further, so it is also effective for smaller amounts of
debitage from all siliceous materials used by humans to produce
debitage, and at maximum depths in the sediment. There should
also be no water-depth limitation when operating the system.
Since Stone Age sites can be expected to be found down to
approximately í140 m below present sea level (the lowest glacial
sea level), the system will support the practical implementation of
UNESCO’s 2001 convention for underwater cultural heritage,
which also covers international waters [1]. The existing types of
predictive modelling, based on the bathymetry of former exposed
and inhabited surfaces, are very imprecise and expensive, taking
into account the costs of precise physical mapping of the potential
sites by coring.