NOAA Maritime Archaeologist Tane Casserley (center) briefs Ryan Harris (left) and John Moore (right) of Parks Canada before creating a photo mosaic of the Lucinda Van Valkenburg.
NOAA Shares its Preservation Techniques with Parks Canada
Date: June 6, 2007
Entry by: Heather Hohman and Sarah Newman, Summer Fellowship Students, Thunder Bay National Marine Sanctuary
"The screams of history are beckoning me forth" exclaimed Tane Casserley as he splashed into the water of Thunder Bay, followed by fellow divers from NOAA and Parks Canada.
Outside researchers are often welcomed as partners with NOAA at the Thunder Bay National Marine Sanctuary (TBNMS) to exchange preservation information and methodologies. This week, John Moore and Ryan Harris of the Underwater Archaeological Services from Parks Canada are visiting TBNMS to work with Tane Casserley, Maritime Archaeologist from NOAA's Maritime Heritage Program.
Casserley introduced Moore and Harris to the specifics of his work through a presentation on photo mosaics. This technique enables archaeologists to document underwater archaeological sites with greater efficiency and minimal impact to the wreck itself. Using a propulsion sled equipped with SONAR and a video camera, underwater archaeologists glide through the water above a wreck to obtain a continuous stream of visual images of the site. After the dive, computer software is used to pull individual images from the footage. These single frames are then stitched together electronically to create a single composite image of the entire wreck.
Yesterday, assisted by Joe Hoyt, a graduate student in the Maritime Studies Program at East Carolina University, and Michigan State Underwater Archaeologist Wayne Lusardi, Casserley invited Moore and Harris out into the waters of Thunder Bay to get a feel for using the tools and techniques to create photo mosaics.
We arrived at the Lucinda Van Valkenburg, a two-masted wooden schooner built in 1862 and later lost in a collision in 1887. Resting in 70-feet of water, the Lucinda Van Valkenburg (affectionately known as "Lucy") provided an excellent training platform for Casserley's demonstration. By sharing the photo mosaic techniques used at TBNMS with Parks Canada, researchers are able to cooperate in the work of, as Casserley describes, "bringing shipwrecks to the surface for people to experience these incredibly preserved wrecks". By sharing this technology, TBNMS also extends its shipwreck preservation methods to other regions and countries and ultimately increases professional and public knowledge about preserving cultural resources.
Despite minor setbacks due to weather and some technical difficulties, Moore and Harris were able to experiment with the photo mosaic equipment and process. By the end of the day, they collected enough footage of"Lucy" to produce their own example of a photo mosaic of the wreck.
NOAA Maritime Archaeologist Tane Casserley (center) briefs Ryan Harris (left) and John Moore (right) of Parks Canada before creating a photo mosaic of the Lucinda Van Valkenburg.