Digital Commons Network^™

Law Of The Sea Cruise To Map The Western Insular Margin And 2500-M Isobath Of Guam And The Northern Mariana Islands. Cruise Report, James V. Gardner

Center for Coastal and Ocean Mapping

U.S. Law of the Sea cruise to map the western insular margin and 2500-m isobath of Guam and the Northern Mariana Islands

CRUISE BD06-1

October 13, to November 12, 2006

Naha, Okinawa, Japan to Apra Harbor, Guam

Acoustic Scattering From Mud Volcanoes And Carbonate Mounts, Charles W. Holland, Thomas C. Weber, Giuseppe Etiope

Center for Coastal and Ocean Mapping

Submarine mud volcanoes occur in many parts of the world’s oceans and form an aperture for gas and fluidized mud emission from within the earth’s crust. Their characteristics are of considerable interest to the geology, geophysics, geochemistry, and underwater acoustics communities. For the latter, mud volcanoes are of interest in part because they pose a potential source of clutter for active sonar. Close-range (single-interaction) scattering measurements from a mud volcano in the Straits of Sicily show scattering10–15dB above the background. Three hypotheses were examined concerning the scattering mechanism: (1) gas entrained in sediment at/near mud volcano, (2) gas bubbles and/or …

Detecting Compaction Disequilibrium With Anisotropy Of Magnetic Susceptibility, Kurt Schwehr, Lisa Tauxe, Neal Driscoll, Homa Lee

Center for Coastal and Ocean Mapping

In clay-rich sediment, microstructures and macrostructures influence how sediments deform when under stress. When lithology is fairly constant, anisotropy of magnetic susceptibility (AMS) can be a simple technique for measuring the relative consolidation state of sediment, which reflects the sediment burial history. AMS can reveal areas of high water content and apparent overconsolidation associated with unconformities where sediment overburden has been removed. Many other methods for testing consolidation and water content are destructive and invasive, whereas AMS provides a nondestructive means to focus on areas for additional geotechnical study. In zones where the magnetic minerals are undergoing diagenesis, AMS should …

A Process For Producing Ice Coverage Marine Information Objects (Mios) In Iho S-57 Format, George Dias, David F. Coleman, Ahmed El-Rabbany, Benson Agi, Lee Alexander

Center for Coastal and Ocean Mapping

While global warming may be opening up more Arctic waters in the summer, ice still infests key shipping lanes in the northern hemisphere during the winter months. To safely navigate these areas, mariners rely on daily ice coverage charts produced by national governmental agencies. Ice charts are primarily issued in paper format or as a fax. However, there is increased interest to ice coverage information on vessel navigation systems such as an Electronic Chart and Display Information Systems (ECDIS). However, to do so, the ice information must be provided as a separate layer of information to the Electronic Navigational Chart …

Optical Image Blending For Underwater Mosaics, Fan Gu, Yuri Rzhanov

Center for Coastal and Ocean Mapping

Typical problems for creation of consistent underwater mosaic are misalignment and inhomogeneous illumination of the image frames, which causes visible seams and consequently complicates post-processing of the mosaics such as object recognition and shape extraction. Two recently developed image blending methods were explored in the literature: "gradient domain stitching" and "graph-cut" method, and they allow for improvement of illumination inconsistency and "ghosting" effects, respectively. However, due to the specifics of underwater imagery, these two methods cannot be used within a straightforward manner. In this paper, a new improved blending algorithm is proposed based on these two methods. By comparing with …

Experiments For Multibeam Backscatter Adjustments On The Noaa Ship Fairweather, Luciano E. Fonseca, Brian R. Calder

Center for Coastal and Ocean Mapping

A series of experiments were conducted to adjust and normalize the acoustic backscatter acquired by Reson 8111 and 8160 systems. The dependency of the backscatter on the receiver gain, transmit power, pulse width and acquisition mode was analyzed. Empirical beam patterns are calculated as the difference between the backscatter measured by the sonars and the expected backscatter. Expected acoustic backscatter is estimated based on a mathematical model.

Self-Positioning Smart Buoys, The 'Un-Buoy' Solution: Logistic Considerations Using Autonomous Surface Craft Technology And Improved Communications Infrastructure, Joseph A. Curcio, Philip A. Mcgillivary, Kevin Fall, Andrew Maffei, Kurt Schwehr, Bob Twiggs, Chris Kitts, Phil Ballou

Center for Coastal and Ocean Mapping

Moored buoys have long served national interests, but incur high development, construction, installation, and maintenance costs. Buoys which drift off-location can pose hazards to mariners, and in coastal waters may cause environmental damage. Moreover, retrieval, repair and replacement of drifting buoys may be delayed when data would be most useful. Such gaps in coastal buoy data can pose a threat to national security by reducing maritime domain awareness. The concept of self-positioning buoys has been advanced to reduce installation cost by eliminating mooring hardware. We here describe technology for operation of reduced cost self-positioning buoys which can be used in …

Maximum A Posteriori Resampling Of Noisy, Spatially Correlated Data, John A. Goff, Chris Jenkins, Brian R. Calder

Center for Coastal and Ocean Mapping

In any geologic application, noisy data are sources of consternation for researchers, inhibiting interpretability and marring images with unsightly and unrealistic artifacts. Filtering is the typical solution to dealing with noisy data. However, filtering commonly suffers from ad hoc (i.e., uncalibrated, ungoverned) application. We present here an alternative to filtering: a newly developed method for correcting noise in data by finding the “best” value given available information. The motivating rationale is that data points that are close to each other in space cannot differ by “too much,” where “too much” is governed by the field covariance. Data with large uncertainties …

Significant Tectonic And Climatic Events For The Yakutat Block Collision, Gulf Of Alaska: Pleistocene Glacial Intensification In The St. Elias Mountains And The Relationship Between The Fairweather And Transition Faults, Sean P.S. Gulick, Bryce A. Willems, Jeffrey T. Freymueller, Ross D. Powell, John M. Jaeger, Jay Kalbas, John M. Jaeger, Terry L. Pavlis, Lindsay A, Lowe, Larry A. Mayer, James V. Gardner

Center for Coastal and Ocean Mapping

No abstract provided.

Expedition 302 Summary, Jan Backman, Kathryn Moran, Larry A. Mayer

Center for Coastal and Ocean Mapping

The first scientific drilling expedition to the central Arctic Ocean was completed in September 2004. Integrated Ocean Drilling Program Expedition 302, Arctic Coring Expedition (ACEX), recovered sediment cores to 428 meters below seafloor (mbsf) in water depths of ~1300 m, 250 km from the North Pole. Expedition 302’s destination was the Lomonosov Ridge, hypothesized to be a sliver of continental crust that broke away from the Eurasian plate at ~56 Ma. As the ridge moved northward and subsided, marine sedimentation occurred and continues to the present, resulting in what was anticipated from seismic data to be a continuous paleoceanographic record. …

Optimal Image Blending For Underwater Mosaics, Fan Gu, Yuri Rzhanov

Center for Coastal and Ocean Mapping

No abstract provided.

Mariner Perceptions Regarding The Display Of Uncertainty On Nautical Charting Products, Brian Heap

Center for Coastal and Ocean Mapping

No abstract provided.

Automated Generation Of Geo-Referenced Mosaics From Video Collected By Deep Submergence Vehicles: An Example From Rosebud Vent (Galapagos Rift), Stace E. Beaulieu, Tim M. Shank, Adam Soule, D J. Fornari, Yuri Rzhanov, Larry A. Mayer

Center for Coastal and Ocean Mapping

No abstract provided.

A Multibeam Survey Of Mid-Seneca Lake: Bathymetry, Backscatter, And Invasive Species, Thomas C. Weber, Anthony P. Lyons

Center for Coastal and Ocean Mapping

No abstract provided.