2008 Remote Sensing Project
In 2008, archaeologists spent several weeks surveying the sanctuary with multibeam sonar and side scan sonar to locate maritime heritage resources. Survey areas were chosen based on historically reported vessel losses and fishing hangs.
New England’s stormy and unpredictable weather sank many vessels in the
sanctuary (courtesy of LARC).
In June, archaeologists used the NOAA Ship Nancy Foster’s Simrad 1002 multibeam sonar. The multibeam sonar uses a fan-shaped acoustic beam to measure the seafloor’s depth along a swath 3 times the depth of the water. Multibeam is a particularly useful system for gathering data for large scale mapping efforts and finding largely intact shipwrecks. The Nancy Foster’s hull mounted multibeam sonar helped archaeologist map areas in the sanctuary where rugged bottom topography and the presence of fixed fishing gear make it hard to tow a side scan sonar.
NOAA ship using multibeam sonar to map the
seafloor (Courtesy of NOAA).
NOAA ship Nancy Foster’s computer lab set up with the
multibeam data acquisition equipment.
Several times throughout the year, archaeologists utilized the sanctuary’s research vessel Auk for side scan sonar surveys. The side scan sonar uses high frequency sound pulses to map the seafloor with a high degree of resolution. Objects that project above the seafloor, such as shipwrecks or rocks, reflect the sound back to the sonar towfish creating almost photographic images.