COMPARISON OF SEABED FEATURES WITHIN THE RICHARDSON RIDGE COMPLEX, BLAKE PLATEAU

As part of the Windows to the Deep 2018 expedition, scientists from the NOAA Office of Ocean Exploration and Research, US Geological Survey, Smithsonian Institution, and College of Charleston collected multibeam sonar data and high definition video of the seafloor off the Southeast U.S. Continental Margin between May and July of 2018. Bathymetric data were obtained using a Kongsberg EM302 aboard the NOAA Ship Okeanos Explorer and were post-processed using CARIS HIPS and SIPS 10.4. The high definition video was used to ground truth bathymetric surfaces. The expedition’s discovery of deep-sea coral habitat in this area and subsequent exploration by the DSV Alvin of adjacent expanses of similar habitat have generated new ideas on the geomorphology of deep-sea coral habitat. Thus, the purpose of this study is to characterize the geomorphology of the newly discovered deep-sea coral mounds for comparison with the geomorphology of other seabed features in the area referred to as the Richardson Ridge Complex. This area is approximately 160 miles off the coast of Charleston, SC on the eastern edge of the Blake Plateau with depths between 700-900 meters. In order to manage and protect critical benthic habitats, we must be able to properly characterize their geomorphology. Data collected from the bathymetric surfaces revealed that there are weak to no correlations among slope, intensity, and the presence of corals in these deep-sea environments, therefore we cannot rely on the traditional markers of high slope and high intensity to indicate the presence of coral habitat. Instead, using bathymetric data to identify mound features and locate mound crests can aid in finding coral habitat and live corals.