By John Wagner
Office of National Marine Sanctuaries
SRI International's AUV is being tested at the dock in Ocracoke, NC before taking the piece of equipment offshore. (NOAA)
Today has been quite an action-packed day on the Battle of the Atlantic Expedition despite the fact that the research vessel never left the dock. It began early this morning with the SRI International AUV operators and technicians arriving at the dock and loading the AUV that will be deployed during the next phase of the mission. This AUV will use two different high-resolution multibeam sonar systems to scan the seafloor for cultural remains resulting in a collection of high-resolution 3D graphics. This information will help us analyze anomalies, or spots of interest, identified during the wide area sonar survey to determine if they are shipwrecks, abandoned fishing gear, or other manmade objects scattered on the seafloor.
An example of a sonar image with anomalies. Over the course of the BOTA project, scientists will revisit anomalies to collect higher resolution imagery in an attempt to identify the exact shipwrecks the anomalies represent. (NOAA Ocean Explorer)
Before we put the high-resolution sonar into the water, however, we needed to analyze the sonar data collected during the first phase of the expedition. This is what was done this afternoon and late into the night. Four of the maritime archaeologists on the project sat crammed around a computer monitor analyzing the 120 square miles of sonar data collected during the previous week. This analysis entailed identifying promising looking anomalies and noting their locations and any sonar signatures commonly seen in conjunction with shipwrecks such as the evidence of scouring around the anomaly or acoustic shadows cast by objects standing proud of the seafloor.
After many hours spent flagging multiple different anomalies, we picked out the most promising targets, which we will attempt to survey with the high-resolution sonar this week. Now it is time to hope for good weather, calm seas, and a successful mission scanning the seafloor for shipwrecks.