Acoustic Mapping of Submerged Stone Age Sites—A HALD Approach

Ole Grøn,Antonio Dell’Anno,Arne Sjöström,Philippe Blondel,Morgan F Smith,Changqing Hu,Xing Gao,Björn Nilsson,Ehud Galili,Qunyan Ren,Rostand Tayong Boumda,Shawn Joy,Egon Nørmark,Deborah Cvikel,Lars Ole Boldreel,Petra Stråkendal,Niels Bleicher,Bo Madsen,Andreas Mäder

doi:10.3390/rs13030445

Abstract

Acoustic response from lithics knapped by humans has been demonstrated to facilitate effective detection of submerged Stone Age sites exposed on the seafloor or embedded within its sediments. This phenomenon has recently enabled the non-invasive detection of several hitherto unknown submerged Stone Age sites, as well as the registration of acoustic responses from already known localities. Investigation of the acoustic-response characteristics of knapped lithics, which appear not to be replicated in naturally cracked lithic pieces (geofacts), is presently on-going through laboratory experiments and finite element (FE) modelling of high-resolution 3D-scanned pieces. Experimental work is also being undertaken, employing chirp sub-bottom systems (reflection seismic) on known sites in marine areas and inland water bodies. Fieldwork has already yielded positive results in this initial stage of development of an optimised Human-Altered Lithic Detection (HALD) method for mapping submerged Stone Age sites. This paper reviews the maritime archaeological perspectives of this promising approach, which potentially facilitates new and improved practice, summarizes existing data, and reports on the present state of development. Its focus is not reflection seismics as such, but a useful resonance phenomenon induced by the use of high-resolution reflection seismic systems.

Highlights

The increasing focus in archaeology on early human development, supported by, for example, improved and faster methods for the analysis of ancient DNA, suffers a central problem in that a large part of the relevant palaeo-landscape is today submerged and difficult to detect with existing maritime archaeological methods
This paper presents an innovative and cost-effective acoustic Human-Altered Lithic Detection (HALD) approach to mapping submerged Stone Age sites, which is currently under development
The first observations of an acoustic response from knapped lithics obtained on an experimental basis were at the Atlit Yam site in Israel, where huge noise features

Summary

Introduction

The increasing focus in archaeology on early human development, supported by, for example, improved and faster methods for the analysis of ancient DNA, suffers a central problem in that a large part of the relevant palaeo-landscape is today submerged and difficult to detect with existing maritime archaeological methods. Since the sea level has been lower than today for 90% of human history and fell to around –120 m at the height of glaciations, we lack data from up to 9% of the Earth’s surface, representing highly productive prehistoric coastal ecosystems. This undiscovered land must have been of huge significance for early human dispersal and subsistence [11,12,13,14,15]. We may be missing the central part of the picture, including an understanding of Palaeolithic cultures, their subsistence strategies, and population dynamics (e.g., Figure 1)

Methods

Results

Discussion

Conclusion