OS43A-1997
Ultra-high Resolution Mapping of the Inner Crater of the Active Kick'em Jenny Volcano
Thursday, 17 December 2015
Poster Hall (Moscone South)
Laney Hart1, Carly Scott2, Masako Tominaga3, Clara Smart4, Ian Vaughn4, Chris Roman4 and Steven Carey5, (1)Michigan State University, Geological Sciences, East Lansing, MI, United States, (2)Michigan State University, East Lansing, MI, United States, (3)Texas A & M University College Station, College Station, TX, United States, (4)University of Rhode Island, Graduate School of Oceanography, Narragansett, RI, United States, (5)University of Rhode Island Narragansett Bay, Narragansett, RI, United States
Abstract:
We conducted high-resolution geological characterization of a 0.015km^2 region of the inner crater of the most active submarine volcano in the Caribbean, Kick’em Jenny, located 8 km off Grenada in the Lesser Antilles Island Arc. We obtained digital still images and microbathymetery at an altitude of 3 m from the seafloor by using stereo cameras and a BlueView system mounted on Remotely Operated Vehicle (ROV) Hercules during the NA054 cruise on E/V Nautilus (Sept. - Oct. 2014). The seafloor images were processed to construct 2-D photo mosaics of the survey area using Standard Hercules Imaging Suite. We systematically classified the photographed seafloor geology based on the distribution of seafloor morphology and the observable rock fragment and outcrop sizes. The center of the crater floor shows a smooth, coherent texture with little variation in sea floor morphology. From immediately outside this area toward the crater rim, we observe an extensive area covered with outcrops, small rocks, and sediment: and within this area, (1) the north section is partially covered by uneven outcrops with elongated lineaments and a course, rugged seafloor with individual rock fragments observable; (2) the middle section contains high variability and heterogeneity in seafloor morphology in a non-systematic manner; and (3) overall, the southern most section displays subdued seafloor features both in space and variability compared to the other areas. The distributions of rock fragments were classified into four distinct sizes. We observe: (i) little variation in size distribution near the center of the crater floor; and (ii) rock fragment size increasing toward the rim of the crater. To obtain a better understanding of the link between variation in seafloor morphology, rock size distribution, and other in situ processes, we compare our observations on the digital photo mosaic to bathymetry data and ROV visuals (e.g. vents and bacterial mats).
