The Australian Historic Shipwreck Preservation Project: In situ Preservation and Long-Term Monitoring of the Clarence (1850) and James Matthews (1841) Shipwreck Sites

Quantifying Depth of Burial and Composition of Shallow Buried Archaeological Material: Integrated Sub-bottom Profiling and 3D Survey Approaches

“…10.1). Here water depths range 1.5-2.8 m and the calcareous sediments have been characterized as medium sands with some coarse-grained skeletal material (Richards et al 2009). European oak and pine represent timbers commonly used in European shipbuilding (Zisi 2016), and Australian hardwood was commonly used in Australian colonial-period shipbuilding (O'Reilly 2007;Pemberton 1979;Staniforth and Shefi 2014).…”

“…10.1) is described by Henderson (2009). The wreck covers an area 26 × 7 m and is mostly buried to a depth of 1.5-2.0 m in medium grained (phi = 1.5) calcareous sand with the starboard side preserved to the bulwarks by the sand cover (Richards 2001;Richards et al 2009). Following its discovery in July 1973, WAM undertook multiple maritime archaeological excavations on the James Matthews site between 1974 and 1977, and during the extensive 1975-1976 excavation, surveyed and recorded the entire remaining ship's structure using a 3D recording grid frame and plumblines (Baker and Henderson 1979;Henderson 1977).…”

“…However, the assumed speed of sound through the sediment column has a greater effect on DoB estimates. Based on Richards et al (2009) characterization of the sediments over the adjacent James Matthews wreck site, a sediment velocity correction factor of 1.195 can be applied to the speed of sound in the water column. This correction factor was derived by Robb et al (2005) from in situ measurements of the speed of sound in intertidal medium grained sands.…”

“…The trend in maritime archaeology to favour in situ preservation over more destructive methods, has led to an increased need to measure burial depths and composition of shallowburied material using non-invasive methods. This has been discussed widely within the archaeological community (Bergstrand and Godfrey 2007;Gregory 2007;Richards 2011a;Richards et al 2014;Shefi and Veth 2015) and continues to evolve pragmatically as technological improvements result in the increased discovery of UCH. Simultaneously, excavation, conservation, storage, and display costs continue to increase.…”

“…The ultimate in situ preservation goal for many heritage managers is the ability to maintain or create a stable, protective environment (Manders et al 2008;Ortmann et al 2010) to conserve as much as possible of the currently remaining archaeological material. Decisions on how to achieve this goal need to be based on the understanding of the true site extent, the types of material present and their state of degradation, and the potential exposure of archaeological material on a site (both which is visible on or above the seabed, and which may lie beneath the seabed-and in many situations, is neither visible nor known) (Gregory and Matthiesen 2012;Richards et al 2014;Wheeler 2002;Winton 2015). Burial depth, and the continuity of this sediment coverage through time, is the single most important site-specific influence on the rate of degradation of shipwreck material T. Winton (*) Maritime Archaeology Program, Flinders University, Adelaide, SA, Australia e-mail: wint0062@flinders.edu.au (Stewart 1999;Winton 2015).…”