The discovery of shipwrecks through marine geological mapping

Abstract

Summary form only given. Systematic marine geological mapping of the inner continental shelf off southeast Atlantic Canada has lead to the discovery of up to 80 shipwrecks that represent a substantial archaeological resource as well as a potential hazard to seabed engineering and bottom fishing activity. New technologies such as multibeam bathymetric mapping systems, high-resolution sidescan sonars and magnetometers, together with advances in positioning, have allowed the Canadian Hydrographic Service and the Geological Survey of Canada to build a data base for their discovery. A few shipwrecks have been positively identified on the basis of positional knowledge at the time of sinking or design characteristics of the vessel which allow for comparison with survey data. The shipwrecks range from wooden eighteenth century, to First and Second World War vessels, and include several ships sunk during the past 40 years. In addition to their cultural value, they represent time markers on the seabed and can be used to understand sediment dynamics and the long-term effects of storms and currents on seabed stability. They can also be used to study the effects of metal corrosion over time. For example, rusticles from HMCS Clayoquoi, similar to those found on the RMS Titanic, are presently under study. Many of the military vessels contain a variety of unexploded ordinance which represents a seabed hazard to a broad range of activities. Submersible and survey investigations are continuing to identify each of the shipwrecks, as they collectively represent a substantial resource for archaeological research and ecotourism, and as such, must be considered in models of sustainable resource management for the coastal zone. The Acorn, Trongate, Governor Cornwallis, Gertrude de Costa, Havana, Good Hope, British Freedom, HMCS Clayoquot and the Athel Viking are shipwrecks which are presented and discussed. Due to sensitive archaeological and military aspects of some of the shipwrecks discussed in this presentation, a formal paper will not be prepared. Many of the shipwrecks have recently been discovered and a proper assessment has not been conducted.