Whitcomb
Louis L.
Whitcomb
Louis L.
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Technical ReportElevators - autonomous transporters for deep sea benthic sample recovery(Woods Hole Oceanographic Institution, 2000-01) Bowen, Martin F. ; Bernard, P. J. ; Gleason, D. E. ; Whitcomb, Louis L.Two classes of sample recovery devices have been fabricated for use with the Jason deep diving remotely operated vehicle (ROV). One class includes custom-built, autonomous vertical transporters (AVTs) that are capable of raising numerous benthic samples and other payloads to the ocean's surface independent of the sampling RAOV. AVTs are more commonly referred to as sample "elevators". Elevators are inexpensive to construct and can be deployed and recovered many times during the course of a single ROV dive in order to reduce wear and tear on the more expensive ROV. A second class includes a range of custom-built end effectors and articulated scoops that ROV operators mount onto the vehicle's manipulator and sampling cradle according to required sampling tasks. This report describes the design, fabrication, operation, and navigational tracking of these various non-destructive sampling devices. A ballast and flotation spreadsheeet is provided, which allows operators to customize each elevator deployment and sample recovery scenario while the ROV continues its work on the benthos.
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ArticleSubmeter bathymetric mapping of volcanic and hydrothermal features on the East Pacific Rise crest at 9°50′N(American Geophysical Union, 2007-01-19) Ferrini, Vicki L. ; Fornari, Daniel J. ; Shank, Timothy M. ; Kinsey, James C. ; Tivey, Maurice A. ; Soule, Samuel A. ; Carbotte, Suzanne M. ; Whitcomb, Louis L. ; Yoerger, Dana R. ; Howland, Jonathan C.Recent advances in underwater vehicle navigation and sonar technology now permit detailed mapping of complex seafloor bathymetry found at mid-ocean ridge crests. Imagenex 881 (675 kHz) scanning sonar data collected during low-altitude (~5 m) surveys conducted with DSV Alvin were used to produce submeter resolution bathymetric maps of five hydrothermal vent areas at the East Pacific Rise (EPR) Ridge2000 Integrated Study Site (9°50′N, “bull's-eye”). Data were collected during 29 dives in 2004 and 2005 and were merged through a grid rectification technique to create high-resolution (0.5 m grid) composite maps. These are the first submeter bathymetric maps generated with a scanning sonar mounted on Alvin. The composite maps can be used to quantify the dimensions of meter-scale volcanic and hydrothermal features within the EPR axial summit trough (AST) including hydrothermal vent structures, lava pillars, collapse areas, the trough walls, and primary volcanic fissures. Existing Autonomous Benthic Explorer (ABE) bathymetry data (675 kHz scanning sonar) collected at this site provide the broader geologic context necessary to interpret the meter-scale features resolved in the composite maps. The grid rectification technique we employed can be used to optimize vehicle time by permitting the creation of high-resolution bathymetry maps from data collected during multiple, coordinated, short-duration surveys after primary dive objectives are met. This method can also be used to colocate future near-bottom sonar data sets within the high-resolution composite maps, enabling quantification of bathymetric changes associated with active volcanic, hydrothermal and tectonic processes.
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PreprintDiverse styles of submarine venting on the ultraslow spreading Mid-Cayman Rise( 2010-06-24) German, Christopher R. ; Bowen, Andrew D. ; Coleman, Max ; Honig, D. L. ; Huber, Julie A. ; Jakuba, Michael V. ; Kinsey, James C. ; Kurz, Mark D. ; Leroy, S. ; McDermott, Jill M. ; Mercier de Lepinay, B. ; Nakamura, Ko-ichi ; Seewald, Jeffrey S. ; Smith, J. L. ; Sylva, Sean P. ; Van Dover, Cindy L. ; Whitcomb, Louis L. ; Yoerger, Dana R.Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global Mid Ocean Ridge remains unexplored for hydrothermal activity. Of particular interest are the world’s ultra-slow spreading ridges which were the last to be demonstrated to host high-temperature venting, but may host systems particularly relevant to pre-biotic chemistry and the origins of life. Here we report first evidence for diverse and very deep hydrothermal vents along the ~110 km long, ultra-slow spreading Mid-Cayman Rise. Our data indicate that the Mid- Cayman Rise hosts at least three discrete hydrothermal sites, each representing a different type of water-rock interaction, including both mafic and ultra-mafic systems and, at ~5000 m, the deepest known hydrothermal vent. Although submarine hydrothermal circulation, in which seawater percolates through and reacts with host lithologies, occurs on all mid-ocean ridges, the diversity of vent-types identified here and their relative geographic isolation make the Mid-Cayman Rise unique in the oceans. These new sites offer prospects for: an expanded range of vent-fluid compositions; varieties of abiotic organic chemical synthesis and extremophile microorganisms; and unparalleled faunal biodiversity - all in close proximity.
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ArticleInfluence of ice thickness and surface properties on light transmission through Arctic sea ice(John Wiley & Sons, 2015-09-04) Katlein, Christian ; Arndt, Stefanie ; Nicolaus, Marcel ; Perovich, Donald K. ; Jakuba, Michael V. ; Suman, Stefano ; Elliott, Stephen M. ; Whitcomb, Louis L. ; McFarland, Christopher J. ; Gerdes, Rudiger ; Boetius, Antje ; German, Christopher R.The observed changes in physical properties of sea ice such as decreased thickness and increased melt pond cover severely impact the energy budget of Arctic sea ice. Increased light transmission leads to increased deposition of solar energy in the upper ocean and thus plays a crucial role for amount and timing of sea-ice-melt and under-ice primary production. Recent developments in underwater technology provide new opportunities to study light transmission below the largely inaccessible underside of sea ice. We measured spectral under-ice radiance and irradiance using the new Nereid Under-Ice (NUI) underwater robotic vehicle, during a cruise of the R/V Polarstern to 83°N 6°W in the Arctic Ocean in July 2014. NUI is a next generation hybrid remotely operated vehicle (H-ROV) designed for both remotely piloted and autonomous surveys underneath land-fast and moving sea ice. Here we present results from one of the first comprehensive scientific dives of NUI employing its interdisciplinary sensor suite. We combine under-ice optical measurements with three dimensional under-ice topography (multibeam sonar) and aerial images of the surface conditions. We investigate the influence of spatially varying ice-thickness and surface properties on the spatial variability of light transmittance during summer. Our results show that surface properties such as melt ponds dominate the spatial distribution of the under-ice light field on small scales (<1000 m2), while sea ice-thickness is the most important predictor for light transmission on larger scales. In addition, we propose the use of an algorithm to obtain histograms of light transmission from distributions of sea ice thickness and surface albedo.
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ArticleScientific challenges and present capabilities in underwater robotic vehicle design and navigation for oceanographic exploration under-ice(MDPI, 2020-08-11) Barker, Laughlin D. L. ; Jakuba, Michael V. ; Bowen, Andrew D. ; German, Christopher R. ; Maksym, Ted ; Mayer, Larry A. ; Boetius, Antje ; Dutrieux, Pierre ; Whitcomb, Louis L.This paper reviews the scientific motivation and challenges, development, and use of underwater robotic vehicles designed for use in ice-covered waters, with special attention paid to the navigation systems employed for under-ice deployments. Scientific needs for routine access under fixed and moving ice by underwater robotic vehicles are reviewed in the contexts of geology and geophysics, biology, sea ice and climate, ice shelves, and seafloor mapping. The challenges of under-ice vehicle design and navigation are summarized. The paper reviews all known under-ice robotic vehicles and their associated navigation systems, categorizing them by vehicle type (tethered, untethered, hybrid, and glider) and by the type of ice they were designed for (fixed glacial or sea ice and moving sea ice).