Assessing the Utility of Open-Access Bathymetric Data for Shipwreck Detection in the United States

Abstract

Investigation of submerged cultural heritage is an important area of archeological focus. However, the expense of acquiring the necessary data to conduct studies of underwater landscapes is often prohibitive to many researchers. Within the United States, highly resolved bathymetric data are openly available from governmental agencies, and yet little to no marine archaeological exploration has occurred using this information. Here, we investigate the archaeological utility of freely available bathymetric datasets from the National Oceanic and Atmospheric Administration (NOAA) in the United States. These datasets have not previously been utilized for archaeological publications, and include swath bathymetric and topographic LiDAR data, which are widely used by marine archaeologists. We present three case studies from Long Island, New York, coastal Massachusetts (on the Eastern coast of North America), and New Orleans (on the Gulf Coast of North America) to demonstrate the potential of this open-access information for locating shipwreck sites. Results indicate that shipwrecks at varying levels of preservation can be identified at depths up to 160 m, and that even in extremely turbid waters, bathymetric LiDAR can detect some wreckage. Following this assessment, we develop an automated shipwreck detection procedure using an inverse depression analysis. Our results are promising for automated detection methods in marine archaeology research. We argue that archaeologists in the United States should take advantage of these freely available data, as it is possible that these bathymetric data can be used for detection and conservation of cultural and environmental resources even without large funding acquisitions.