Researchers from the Center for Coastal and Ocean Mapping Joint Hydrographic Center in New Hampshire have utilised a C-Worker 4 Autonomous Vessel equipped with a multibeam sonar to map around the NOAA Channel Islands National Marine Sanctuary.
The Center is working in partnership with the Ocean Exploration Trust and operating from Exploration Vessel (E/V) Nautilus, a 64-meter research boat.
The C-Worker 4 ASV was designed to complete a variety of offshore and inshore survey tasks and was delivered to the University of New Hampshire in 2016.
The Ocean Exploration Trust was founded in 2008 by Dr. Robert Ballard—best known for his discovery of RMS Titanic’s final resting place. This 2017 Nautilus Expedition launches the third year of exploration in the Eastern Pacific Ocean, and will be one of the most extensive seasons to date. From May, Nautilus began to document and survey unexplored regions from British Columbia, Canada, along the West Coast of the United States, to Baja California, Mexico and will continue to do so until November.
The Channel Islands National Marine Sanctuary (CINMS) is one of the agencies tasked with the protection of deep-water habitats, commercially important species, and deep-sea coral ecosystems around the islands, yet lacks a detailed understanding of the distribution, abundance, and condition of the resources within the Sanctuary. Less than 50% of the seafloor within the CINMS boundaries has been mapped by high-resolution sonar, and the 2016 Nautilus expedition to the same region worked to cut this knowledge gap nearly in half.
The 2017 expedition continues this exploration by using a high-resolution mapping system to collect sonar bathymetry and sub-bottom profiling data to characterize the seafloor in these unmapped areas. The C-Worker 4 ASV can map waters and caves as deep as 600ft, and is remotely controlled by operators aboard Nautilus during these tests. These mapping surveys are helping the team locate and document submerged caves along the Channel Islands for future surveys.
Following mapping operations using the C-Worker 4 ASV, Nautilus will utilize ROVs to undertake visual surveys, collect high-definition video imagery, collect biological and geological samples, and ground truth the newly-collected multibeam data.
This cruise will also be part of a larger initiative to understand sea level history and locate, map, and document submerged paleo-shorelines in the Channel Islands region. This region has a complex geologic history following its initial volcanic formation, later being shaped by uplift, sinking, and fluctuating sea levels, and resulting in a submerged shoreline of boulders, spires, caves, and arches.