Digital Commons Network^™

Acoustic And Optical Observations Of Methane Gas Seeps In The Gulf Of Mexico, Thomas C. Weber, Kevin W. Jerram, Yuri Rzhanov, Larry A. Mayer, Dave Lovalvo

Center for Coastal and Ocean Mapping

In 2011 and 2012, measurements of acoustic backscatter from natural methane seeps were made in the northern Gulf of Mexico in water depths between 1000-2000 m. The measurementswere made using a calibrated 18 kHz echo sounder with an 11 degree beamwidth in order to estimate the depth-dependent target strength (TS). The TS data indicate a wide variation in the rate of gas seepage from the seafloor. Several of these seeps were revisited with a remotely operated vehicle in order to optically assess the bubble size distribution and to estimate the rate at which gas bubbles were exiting the seafloor. The …

Satellite-Derived Bathymetry A Reconnaissance Tool For Hydrography, Shachak Pe'eri, Chukwuma Azuike, Christopher Parrish

Center for Coastal and Ocean Mapping

In some developing countries, the information available to plan and prioritise hydrographic surveys is typically based on visual inspection of existing nautical charts. However, due to the age of many existing charts and lack of availability of the original source data from which they were compiled (e.g., smooth sheets) this type of analysis is often quite limited. A study was conducted to evaluate the use of a satellite-derived bathymetry (SDB) procedure to map shallow-water bathymetry in a GIS environment, and to identify areas that require a new hydrographic survey. Publically available, multispectral satellite imagery and published algorithms are used to …

R/V Falkor Multibeam Echosounder System Review, Jonathan Beaudoin, Paul D. Johnson, Ashton F. Flinders

Center for Coastal and Ocean Mapping

No abstract provided.

Underwater Radiated Noise Levels Of A Research Icebreaker In The Central Arctic Ocean, Ethan H. Roth, Val E. Schmidt, John A. Hildebrand, Sean M. Wiggins

Center for Coastal and Ocean Mapping

U.S. Coast Guard Cutter Healy's underwater radiated noise signature was characterized in the central Arctic Ocean during different types of ice-breaking operations. Propulsion modes included transit in variable ice cover, breaking heavy ice with backing-and-ramming maneuvers, and dynamic positioning with the bow thruster in operation. Compared to open-water transit, Healy's noise signature increased approximately 10 dB between 20 Hz and 2 kHz when breaking ice. The highest noise levels resulted while the ship was engaged in backing-and-ramming maneuvers, owing to cavitation when operating the propellers astern or in opposing directions. In frequency bands centered near 10, 50, and 100 Hz, …

Parallel And Distributed Performance Of A Depth Estimation Algorithm, Brian R. Calder

Center for Coastal and Ocean Mapping

Expansion of dataset sizes and increasing complexity of processing algorithms have led to consideration of parallel and distributed implementations. The rationale for distributing the computational load may be to thin-provision computational resources, to accelerate data processing rate, or to efficiently reuse already available but otherwise idle computational resources. Whatever the rationale, an efficient solution of this type brings with it questions of data distribution, job partitioning, reliability, and robustness. This paper addresses the first two of these questions in the context of a local cluster-computing environment. Using the CHRT depth estimator, it considers active and passive data distribution and their …

Experimental And Natural Warming Elevates Mercury Concentrations In Estuarine Fish, Jennifer A. Dijkstra, Kate L. Buckman, Darren Ward, David W. Evans, Michele Dionne, Celia Chen

Center for Coastal and Ocean Mapping

Marine food webs are the most important link between the global contaminant, methylmercury (MeHg), and human exposure through consumption of seafood. Warming temperatures may increase human exposure to MeHg, a potent neurotoxin, by increasing MeHg production as well as bioaccumulation and trophic transfer through marine food webs. Studies of the effects of temperature on MeHg bioaccumulation are rare and no study has specifically related temperature to MeHg fate by linking laboratory experiments with natural field manipulations in coastal ecosystems. We performed laboratory and field experiments on MeHg accumulation under varying temperature regimes using the killifish, Fundulus heteroclitus. Temperature treatments were …

Satellite-Derived Bathymetry Of The Achziv Coastal Area, Northern Israel, Shachak Pe'eri, Gideon Tibor, Brian Madore, Tomer Ketter

Center for Coastal and Ocean Mapping

No abstract provided.

Exploration Of Eratosthenes Seamount – A Continental Fragment Being Forced Down An Oceanic Trench, Garrett Mitchell, Larry A. Mayer, Katherine L.C. Bell, Nicole A. Raineault, Chris Roman, Robert D. Ballard, Kelsey Cornwell, Al Hine, Eugene Shinn, Iordanis Dimitriadis, Onac Bogdan

Center for Coastal and Ocean Mapping

No abstract provided.

Future Directions In Hydrography Using Satellite-Derived Bathymetry, Shachak Pe'eri, Christopher Parrish, Lee Alexander, Chukwuma Azuike, Andy Armstrong, Maryellen Sault

Center for Coastal and Ocean Mapping

Satellite remote sensing provides useful reconnaissance tool for mapping near-shore bathymetry, characterizing a coastal area and monitoring any seafloor changes that may have occurred since the last hydrographic survey of the area. At the 2012 Canada Hydro conference, a study was presented on the potential use of Landsat satellite imagery to map shallow-water bathymetry in a GIS environment over three study sites. Since then, several collaborations between the current study group and various hydrographic organizations were established with the goal of implementing optically-derived bathymetry as part of their data acquiring procedure. Bathymetry over additional study sites around the world was …

Developing An Acceptance Test For Non-Hydrographic Airborne Bathymetric Lidar Data Application To Noaa Charts In Shallow Waters, Gretchen Imahori, Shachak Pe'eri, Christopher Parrish, Toshi Wozumi, Stephen A. White, Inseong Jeong, Christopher L. Macon

Center for Coastal and Ocean Mapping

Hydrographic data of the National Oceanic and Atmospheric Administration are typically acquired using sonar systems, with a small percent acquired via airborne lidar bathymetry for nearshore areas. This study investigates an integrated approach to meeting NOAA’s hydrographic survey requirements for nearshore areas of NOAA charts using existing U.S. Army Corps of Engineers (USACE) National Coastal Mapping Program (NCMP) topographic-bathymetric lidar (TBL) data. Because these existing NCMP bathymetric lidar datasets were not collected to NOAA hydrographic surveying standards, it is unclear if, and under what circumstances, they might aid in meeting certain hydrographic surveying requirements. The NCMP bathymetric lidar data were …

Oceanographic Weather Maps: Using Oceanographic Models To Improve Seabed Mapping Planning And Acquisition, Jonathan Beaudoin, John G.W. Kelley, Jason Greenlaw, Tami Beduhn, Samuel F. Greenaway

Center for Coastal and Ocean Mapping

In a world of high precision sensors, one of the few remaining challenges in multibeam echosounding is that of refraction based uncertainty. A poor understanding of oceanographic variability can lead to inadequate sampling of the water mass and the uncertainties that result from this can dominate the uncertainty budget of even state-of-the-art echosounding systems. Though dramatic improvements have been made in sensor accuracies over the past few decades, survey accuracy and efficiency is still potentially limited by a poor understanding of the “underwater weather”. Advances in the sophistication of numerical oceanographic forecast modeling, combined with ever increasing computing power, allow …

Report On The 2010 Rapid Assessment Survey Of Marine Species At New England Floating Docks And Rocky Shores., Christopher M. Mcintyre, Adrienne L. Pappal, Jessica Bryant, James T. Carlton, Kevin Cute, Jennifer A. Dijkstra, Renee Erickson, Yvette L. Garner, Arriaan Gittenberger, Sara P. Grady, Linsey Haram, Larry G. Harris, Niels-Viggo Hobbs, Charles C. Lambert, Gretchen Lambert, Walter J. Lambert, Antonio Carlos Marques, Arthur C. Mathieson, Megan Mcculler, Miranda Mickiewicz, Judith Pederson, Rachel Rock-Blake, Jan P. Smith, Cascade Sorte, Lauren Stefaniak, Martine Wagstaff

Center for Coastal and Ocean Mapping

No abstract provided.

Distribution-Free, Variable Resolution Depth Estimation With Composite Uncertainty, Brian R. Calder

Center for Coastal and Ocean Mapping

Recent algorithms for processing hydrographic data have treated the problem of achievable resolution by constructing grids of fixed resolution, a composite grid of variable resolution, recursive sub-division in a quad-tree, or by relying on a comprehensive TIN of the original points. These algorithms all impose some artificial structure on the data to allow for efficient computation, however, which this paper attempts to address. A scheme is outlined which provides a robust estimate of depth and associated uncertainty that makes as few assumptions as possible. Using a non-uniform spectral analysis, it estimates the spatial scales at which the data are consistent …

A Single Vessel Approach To Inter-­Vessel Normalization Of Seafloor Backscatter Data, Samuel F. Greenaway, Glen Rice

Center for Coastal and Ocean Mapping

Integration!of!backscatter!data!from!multiple!unTcalibrated!echosounders remains!a!challenge.!! The!arbitrary!offsets!that!are!acceptable!within!a!single!sensor!application!become!problematic! when!integrating!multiple!sensors!into!a!common!data!set.!!Instruments!typically!have! differences!in!overall!sensitivities!and/!or!beam!patterns!that!are!large!enough!to!complicate! the!combination!of!the!individual!sensor!data!sets!into!a!coherent,!project!wide!product.! The!dualThead!Reson!7125!installation!on!the!NOAA!Ship!Ferdinand!R.!Hassler!is!useful! intermediate!step!between!a!single!instrument!installation!and!a!true!multiTvessel!application.!! When!operated!simultaneously,!the!temporal!variation!in!the!acoustic!properties!of!the! seafloor!and!the!water!column!can!be!eliminated!between!the!two!systems.!!! Using!data!acquired!during!production!hydrography,!we!solve!for!the!offsets!between!the!two! heads!for!simultaneously!logged!data.!!This!approach!is!then!broadened!to!determine!offsets! between!different!days,!and!then!different!hardware!installations!throughout!the!project.!!!We! find!that!the!normalization!offsets!vary!significantly!between!the!heads,!between!different!runs! (likely!due!to!the!Reson!normalization process),!and!different!installed!receiver!components.!! Accounting!for!these!offsets,!we!are!able!to!generate!project!wide!mosaics!and!backscatter! products.

Water-Column Variability Assessment For Underway Profilers To Improve Efficiency And Accuracy Of Multibeam Surveys, Matt Wilson, Jonathan Beaudoin, Steve Smyth

Center for Coastal and Ocean Mapping

With the advent of underway profilers, sampling the water-column to obtain sound speed corrections is no longer a detriment to hydrographic survey efficiency. Instead, the challenge has become deciding how many casts are necessary to maintain a desired level of multibeam sounding accuracy, while not needlessly overworking the profiler. Ray tracing uncertainty analysis can determine in hindsight whether a particular sampling interval is adequate or not. Based on this methodology, an algorithm was developed to generate recommended sampling intervals based on successively acquired sound speed profiles, allowing the MVP to run in a “cruise-control” mode where the sampling interval is …

A Procedure For Developing An Acceptance Test For Airborne Bathymetric Lidar Data Application To Noaa Charts In Shallow Waters, Gretchen Imahori, Jeffrey Ferguson, Toshi Wozumi, Dave Scharff, Shachak Pe'eri, Christopher Parrish, Stephen A. White, Inseong Jeong, Jon Sellars, Michael Aslaksen

Center for Coastal and Ocean Mapping

National Oceanic and Atmospheric Administration (NOAA) hydrographic data is typically acquired using sonar systems, with a small percent acquired via airborne lidar bathymetry for near‐shore areas. This study investigated an integrated approach for meeting NOAA’s hydrographic survey requirements for near‐shore areas of NOAA charts, using the existing topographic‐bathymetric lidar data from USACE’s National Coastal Mapping Program (NCMP). Because these existing NCMP bathymetric lidar datasets were not collected to NOAA hydrographic surveying standards, it is unclear if, and under what circumstances, they might aid in meeting certain hydrographic surveying requirements. The NCMP’s bathymetric lidar data are evaluated through a comparison to …

Spectral Characterization Of The Nigerian Shoreline Using Landsat Imagery, Olumide Fadahunsi, Shachak Pe'eri, Christopher Parrish, Andy Armstrong, Lee Alexander

Center for Coastal and Ocean Mapping

The challenges of shoreline mapping include the high costs of acquiring up-to-date survey data over the coastal area. As a result, in many developing countries, the shoreline has not been consistently mapped. The variety of methods used for this mapping and the large time differences between the surveys (on the order of decades) could result in inaccuracies in shoreline data. This study presents the development of a shoreline characterization procedure for the Nigerian coastline using satellite remote sensing technology. The study goal is to produce a complete, consistent and continuous shoreline map using publicly available data processed in a GIS …

Seabed Classification For Trawlability Determined With A Multibeam Echo Sounder On Snakehead Bank In The Gulf Of Alaska, Thomas C. Weber, Chris Rooper, John L. Butler, Darin Jones, Chris Wilson

Center for Coastal and Ocean Mapping

—Rockfishes (Sebastes spp.) tend to aggregate near rocky, cobble, or generally rugged areas that are difficult to survey with bottom trawls, and evidence indicates that assemblages of rockfish species may differ between areas accessible to trawling and those areas that are not. Consequently, it is important to determine grounds that are trawlable or untrawlable so that the areas where trawl survey results should be applied are accurately identified. To this end, we used multibeam echosounder data to generate metrics that describe the seafloor: backscatter strength at normal and oblique incidence angles, the variation of the angle-dependent backscatter strength within 10° …

Ricamar2013: Rilievi Per La Caratterizzazione Dell'ambiente Marino Nel Golfo Di Pozzuoli. Rapporto Sull'attivita 13 - 31 Maggio 2013, C. Carmisciano, M. Grassi, L. Cocchi, Giuseppe Masetti, M. Filippone, E. Ricci, M. Pratellesi, Roberta Ivaldi, Giovanni Iannaccone, Giovanna Berrino, Guiseppe De Natale, Giovanni Chiodini, Sefano Caliro, Lorenzo Dialti, Matteo Guideri, F. Muccini, Paolo Stefanelli, Giovanni Orsi, Valerio Iafolla, Francesco Italiano, Fabrizia Buongiorno, Salvatore Stramondo, Christian Bignami, Marco Polcari, Malvina Silvestri

Center for Coastal and Ocean Mapping

No abstract provided.

Combining Angular And Spatial Information From Multibeam Backscatter Data For Improved Unsupervised Acoustic Seabed Segmentation, Alexandre C. Schimel, Yuri Rzhanov, Luciano E. Fonseca, M Mayer, Dirk Immenga

Center for Coastal and Ocean Mapping

No abstract provided.

Observations Of The Vertical Structure Of Tidal Currents In Two Inlets, Thomas C. Lippmann, James D. Irish, Jonathan Hunt

Center for Coastal and Ocean Mapping

Observations of the vertical structure of broad band tidal currents were obtained at two energetic inlets. Each experiment took place over a 4 week period, the first at Hampton Inlet in southeastern New Hampshire, USA, in the Fall of 2011, and the second at New River Inlet in southern North Carolina, USA, in the spring of 2012. The temporal variation and vertical structure of the currents were observed at each site with 600 kHz and 1200 kHz RDI Acoustic Doppler Current Profilers (ADCP) deployed on low-profile bottom tripods in 7.5 and 12.5 m water depths near the entrance to Hampton …

Bathymetric Terrain Model Of The Atlantic Margin For Marine Geological Investigations., Brian Andrews, Jason D. Chaytor, Uri S. Ten Brink, Daniel S. Brothers, James V. Gardner

Center for Coastal and Ocean Mapping

Bathymetric terrain models of seafloor morphology are an important component of marine geological investigations. Advances in acquisition and processing technologies of bathymetric data have facilitated the creation of high-resolution bathymetric surfaces that approach the resolution of similar surfaces available for onshore investigations. These bathymetric terrain models provide a detailed representation of the Earth’s subaqueous surface and, when combined with other geophysical and geological datasets, allow for interpretation of modern and ancient geological processes. The purpose of the bathymetric terrain model presented in this report is to provide a high-quality bathymetric surface of the Atlantic margin of the United States that …

Scientific Basis For Safely Shutting In The Macondo Well After The April 20, 2010 Deepwater Horizon Blowout, Stephen H. Hickman, Paul A. Hsieh, Walter D. Mooney, Catherine B. Enomoto, Philip H. Nelson, Larry A. Mayer, Thomas C. Weber, Kathryn Moran, P. B. Flemings, Marcia Mcnutt

Center for Coastal and Ocean Mapping

As part of the government response to the Deepwater Horizon blowout, a Well Integrity Team evaluated the geologic hazards of shutting in the Macondo Well at the seafloor and determined the conditions under which it could safely be undertaken. Of particular concern was the possibility that, under the anticipated high shut-in pressures, oil could leak out of the well casing below the seafloor. Such a leak could lead to new geologic pathways for hydrocarbon release to the Gulf of Mexico. Evaluating this hazard required analyses of 2D and 3D seismic surveys, seafloor bathymetry, sediment properties, geophysical well logs, and drilling …

Calibration Of Multibeam Echo Sounders: A Comparison Between Two Methodologies, Carlo Lanzoni, Thomas C. Weber

Center for Coastal and Ocean Mapping

Multibeam echo sounders (MBES) are widely used in applications like seafloor imaging, fisheries, and habitat mapping. Calibration of acoustic backscatter is an important aspect of understanding and validating the performance of a MBES. Combined transmit/receive beampattern calibrations were performed on a 200 kHz Reson Seabat 7125 MBES in the acoustic tank of the University of New Hampshire utilizing two different methodologies. The first methodology employs fixed standard target spheres and a high accuracy/high resolution rotation mechanism. This method, similar to that proposed by Foote et al ["Protocols forcalibrating multibeam sonar", J. Acoust. Soc. Am. 117(4), 2005], is designed for a …

Potentially Polluting Marine Sites Geodb: An S-100 Geospatial Database As An Effective Contribution To The Protection Of The Marine Environment, Giuseppe Masetti, Brian R. Calder, Lee Alexander

Center for Coastal and Ocean Mapping

Potentially Polluting Marine Sites (PPMS) are objects on, or areas of, the seabed that may release pollution in the future. A rationale for, and design of, a geospatial database to inventory and manipu-late PPMS is presented. Built as an S-100 Product Specification, it is specified through human-readable UML diagrams and implemented through machine-readable GML files, and includes auxiliary information such as pollution-control resources and potentially vulnerable sites in order to support analyses of the core data. The design and some aspects of implementation are presented, along with metadata requirements and structure, and a perspective on potential uses of the database.

Chum: Chart Update Mashup, Briana M. Sullivan

Center for Coastal and Ocean Mapping

The Chart Update Mash up (ChUM™) consists of various APIs/Technologies that when brought together allow for intuitive georeferenced visualization of the Critical Chart Updates published by the Office of Coast Survey (OCS). Each component of ChUM™ will be described in this paper with an explanation of how each piece works together to form ChUM™. Figure 1 shows the basic building blocks that make up ChUM™. At the base of the structure (in blue) is the data that OCS disseminates to the public via its website/web-services: Raster Nautical Charts, the CRIT data (critical corrections to the chart), and the Coast Pilot. …

Using A Cruise Report To Generate Xml Metadata, Briana M. Sullivan

Center for Coastal and Ocean Mapping

Since 2005 metadata generation at the Center for Coastal and Ocean Mapping/Joint Hydrographic Center has slowly evolved from a painful and tedious process of copying and pasting, to generate hundreds of files, to using an automated system that generates 90% of the needed metadata from the data collected on cruises. However there remained one piece missing to the automated system- the wordy part of the metadata that deals with information such as the attribute accuracy report, abstract and the process description. This information cannot be mined from the raw survey data. This paper illustrates how to generate a template from …

Measurement Of Micro-Bathymetry With A Gopro Underwater Stereo Camera Pair, Val E. Schmidt, Yuri Rzhanov

Center for Coastal and Ocean Mapping

A GO-PRO underwater stereo camera kit has been used to measure the 3D topography (bathymetry) of a patch of seafloor producing a point cloud with a spatial data density of 15 measurements per 3 mm grid square and an standard deviation of less than 1 cm A GO-PRO camera is a fixed focus, 11 megapixel, still-frame (or 1080p high-definition video) camera, whose small form-factor and water-proof housing has made it popular with sports enthusiasts. A stereo camera kit is available providing a waterproof housing (to 61 m / 200 ft) for a pair of cameras. Measures of seafloor micro-bathymetrycapable of …

Modular Autonomous Biosampler (Mab)- A Prototype System For Distinct Biological Size-Class Sampling And Preservation, Arthur Trembanis, Craig Cary, Val E. Schmidt, Don Clarke, Tristan Crees, Eric Jackson

Center for Coastal and Ocean Mapping

Presently, there is a community wide deficiency in our ability to collect and preserve multiple size-class biologic samples across a broad spectrum of oceanographic platforms (e.g. AUVs, ROVs, and Ocean Observing System Nodes). This is particularly surprising in comparison to the level of instrumentation that now exists for acquiring physical and geophysical data (e.g. side-scan sonar, current profiles etc.), from these same platforms. We present our effort to develop a low-cost, high sample capacity modular,autonomous biological sampling device (MAB). The unit is designed for filtering and preserving 3 distinct biological size-classes (including bacteria), and is deployable in any aquatic setting …

U.S. Law Of The Sea Cruise To Map And Sample The Us Arctic Ocean Margin, Larry A. Mayer, Andy Armstrong

Center for Coastal and Ocean Mapping

U.S. Law of the Sea cruise to map and sample the US Arctic Ocean margin

CRUISE HEALY 1202

August 25 to September 27, 2012

Barrow, AK to Dutch Harbor, AK