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 …

Geostatistical Analysis Of An Experimental Stratigraphy, Y Zhang, M Person, C Paola, C W. Gable, X H. Wen, J M. Davis

Earth Sciences

[1] A high-resolution stratigraphic image of a flume-generated deposit was scaled up to sedimentary basin dimensions where a natural log hydraulic conductivity (ln( K)) was assigned to each pixel on the basis of gray scale and conductivity end-members. The synthetic ln( K) map has mean, variance, and frequency distributions that are comparable to a natural alluvial fan deposit. A geostatistical analysis was conducted on selected regions of this map containing fluvial, fluvial/ floodplain, shoreline, turbidite, and deepwater sedimentary facies. Experimental ln(K) variograms were computed along the major and minor statistical axes and horizontal and vertical coordinate axes. Exponential and power …

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 …

Storm‐Time Configuration Of The Inner Magnetosphere: Lyon‐Fedder‐Mobarry Mhd Code, Tsyganenko Model, And Goes Observations, Chia-Lin L. Huang, Harlan E. Spence, J. G. Lyon, F. R. Toffoletto, H. J. Singer, S. Sazykin

Physics & Astronomy

[1] We compare global magnetohydrodynamic (MHD) simulation results with an empirical model and observations to understand the magnetic field configuration and plasma distribution in the inner magnetosphere, especially during geomagnetic storms. The physics-based Lyon-Fedder-Mobarry (LFM) code simulates Earth's magnetospheric topology and dynamics by solving the equations of ideal MHD. Quantitative comparisons of simulated events with observations reveal strengths and possible limitations and suggest ways to improve the LFM code. Here we present a case study that compares the LFM code to both a semiempirical magnetic field model and to geosynchronous measurements from GOES satellites. During a magnetic cloud event, the …

Effects Of Uncertainty In Climate Inputs On Simulated Evapotranspiration And Runoff In The Western Arctic, Michael A. Rawlins, Steve Frolking, Richard B. Lammers, Charles Vorosmarty

Earth Sciences

Hydrological models require accurate precipitation and air temperature inputs in order to adequately depict water fluxes and storages across Arctic regions. Biases such as gauge undercatch, as well as uncertainties in numerical weather prediction reanalysis data that propagate through water budget models, limit the ability to accurately model the terrestrial arctic water cycle. A hydrological model forced with three climate datasets and three methods of estimating potential evapotranspiration (PET) was used to better understand the impact of these processes on simulated water fluxes across the Western Arctic Linkage Experiment (WALE) domain. Climate data were drawn from the NCEP–NCAR reanalysis (NNR) …

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 …

Characterization Of Single-Sided Charge-Sharing Czt Strip Detectors For Gamma-Ray Astronomy, B Donmez, John R. Macri, James M. Ryan, Jason S. Legere, Mark L. Mcconnell, Mark Widholm, T Narita, L A. Hamel

Space Science Center

We report progress in the study of thick single-sided charge-sharing cadmium zinc telluride (CZT) strip detector modules designed to perform spectroscopy and 3-D imaging of gamma-rays. We report laboratory measurements including spectroscopy, efficiency and 3-D imaging capability of prototype detectors (15 × 15 × 7.5mm³) with 11×11 unit cells. We also report on Monte Carlo simulations (GEANT4 v7.1) to investigate the effect of multihits on detector performance in both spectroscopy and imaging. We compare simulation results with data obtained from laboratory measurements and discuss the implications for future strip detector designs.

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 …

Research On Synthetic Rope And Its Future In Timber Harvesting, Joel N. Hartter, Jared Leonard, John Garland, Steve Pilkerton

Geography

Steel wire rope is used for many logging applications. It has served the industry well in terms of strength, durability, and longevity. However, steel wire rope is difficult to use because it is stiff, heavy, and unyielding. These characteristics can lead to fatigue and exhaustion, and may contribute to worker injuries. Ultra-high molecular weight polyethylene synthetic rope has the potential to replace steel wire rope for selected logging applications. Research shows ergonomic gains and other operational effectiveness with its use. This paper presents research results, potentials, and issues in improving economic and ergonomic performance of ground-based and cable logging. Potential …

Magnetospheric Influence On The Moon's Exosphere, Jody K. Wilson, M. Mendillo, Harlan E. Spence

Physics & Astronomy

[1] Atoms in the thin lunar exosphere are liberated from the Moon's regolith by some combination of sunlight, plasma, and meteorite impact. We have observed exospheric sodium, a useful tracer species, on five nights of full Moon in order to test the effect of shielding the lunar surface from the solar wind plasma by the Earth's magnetosphere. These observations, conducted under the dark sky conditions of lunar eclipses, have turned out to be tests of the differential effects of energetic particle populations that strike the Moon's surface when it is in the magnetotail. We find that the brightness of the …

The Advanced Compton Telescope, S E. Boggs, J Kurfess, James M. Ryan, Elena Aprile, Neil Gehrels, R M. Kippen, Marc Leising, U Oberlack, Cornelia B. Wunderer, Allen Zych, Peter F. Bloser, M Harris, A Hoover, Alexei Klimenk, Dan Kocevski, Mark L. Mcconnell, Peter Milne, E I. Novikova, B F. Phlips, Mark Polsen, Steven Sturner, Derek Tournear, G Weidenspointer, Eric Wulf, A Zoglauer, Matthew Baring, John Beacom, Lars Bildsten, Charles Dermer, Dieter H. Hartman, Margarita Hernanz, David Smith, Sumner Starrfield

Space Science Center

The Advanced Compton Telescope (ACT), the next major step in gamma-ray astronomy, will probe the fires where chemical elements are formed by enabling high-resolution spectroscopy of nuclear emission from supernova explosions. During the past two years, our collaboration has been undertaking a NASA mission concept study for ACT. This study was designed to (1) transform the key scientific objectives into specific instrument requirements, (2) to identify the most promising technologies to meet those requirements, and (3) to design a viable mission concept for this instrument. We present the results of this study, including scientific goals and expected performance, mission design, …

In Situ Evidence For Renitrification In The Arctic Lower Stratosphere During The Polar Aura Validation Experiment (Pave), Jack E. Dibb, Eric Scheuer, Melody A. Avery, G W. Sachse

Earth Sciences

In-situ measurements of nitric acid (HNO₃), ozone (O₃), and nitrous oxide (N₂O) were made from the NASA DC-8 during the Polar Aura Validation Experiment in January/February 2005. In the lower stratosphere (9–12.5 km, potential temperature 300–350 K) characteristic compact relationships were observed between all three gases. The ratio HNO₃/O₃ averaged 3.5 (±0.7) ppt/ppb. Samples with enhanced HNO₃/O₃ (>4.0) were most abundant under the edge of the Arctic Polar vortex in airmasses with enhanced mixing ratios of both gases (>400 ppb O₃ and >2000 ppt HNO …

Fnit: The Fast Neutron Imaging Telescope For Snm Detection, U Bravar, P J. Bruillard, E O. Fluckiger, John R. Macri, Mark L. Mcconnell, M R. Moser, James M. Ryan

Space Science Center

We report on recent progress in the development of the Fast Neutron Imaging Telescope (FNIT), a detector with both imaging and energy measurement capabilities, sensitive to neutrons in the 2-20 MeV range. FNIT was initially conceived to study solar neutrons as a candidate design for the Solar Sentinels program under formulation at NASA. This instrument is now being configured to locate fission neutron sources for homeland security purposes. By accurately identifying the position of the neutron source with imaging techniques and reconstructing the energy spectrum of fission neutrons, FNIT can locate problematic amounts of Special Nuclear Material (SNM), including heavily …

Observations Of Hono By Laser-Induced Fluorescence At The South Pole During Antci 2003, W Liao, A T. Case, J Mastromarino, D Tan, Jack E. Dibb

Earth Sciences

Observations of nitrous acid (HONO) by laser-induced fluorescence (LIF) at the South Pole taken during the Antarctic Troposphere Chemistry Investigation (ANTCI), which took place over the time period of Nov. 15, 2003 to Jan. 4, 2004, are presented here. The median observed mixing ratio of HONO 10 m above the snow was 5.8 pptv (mean value 6.3 pptv) with a maximum of 18.2 pptv on Nov 30th, Dec 1st, 3rd, 15th, 17th, 21st, 22nd, 25th, 27th and 28th. The measurement uncertainty is ±35%. The LIF HONO observations are compared to concurrent HONO observations performed by mist chamber/ion chromatography (MC/IC). The …

Statistical Uncertainty Of Eddy Flux–Based Estimates Of Gross Ecosystem Carbon Exchange At Howland Forest, Maine, Stephen Hagen, Rob Braswell, Ernst Linder, Steve Frolking, Andrew D. Richardson, David Y. Hollinger

Earth Sciences

We present an uncertainty analysis of gross ecosystem carbon exchange (GEE) estimates derived from 7 years of continuous eddy covariance measurements of forest-atmosphere CO₂fluxes at Howland Forest, Maine, USA. These data, which have high temporal resolution, can be used to validate process modeling analyses, remote sensing assessments, and field surveys. However, separation of tower-based net ecosystem exchange (NEE) into its components (respiration losses and photosynthetic uptake) requires at least one application of a model, which is usually a regression model fitted to nighttime data and extrapolated for all daytime intervals. In addition, the existence of a significant amount …

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.

Bioremediation Of An Organically Contaminated Bedrock Aquifer, Maureen A. Lewis

Inquiry Journal 2006

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. …

Lifetimes Of C-60(2-) And C-70(2-) Dianions In A Storage Ring, S. Tomita, J. U. Andersen, H. Cederquist, B. Concina, Olof E. Echt, J. S. Forster, K. Hansen, B. A. Huber, P. Hvelplund, J. Jensen, B. Liu, B. Manil, L. Maunoury

Physics & Astronomy

C-60(2-) and C-70(2-) dianions have been produced by electrospray of the monoanions and subsequent electron pickup in a Na vapor cell. The dianions were stored in an electrostatic ring and their decay by electron emission was measured up to 1 s after injection. While C-70(2-) ions are stable on this time scale, except for a small fraction of the ions which have been excited by gas collisions, most of the C-60(2-) ions decay on a millisecond time scale, with a lifetime depending strongly on their internal temperature. The results can be modeled as decay by electron tunneling through a Coulomb …

The Caster Black Hole Finder Probe, Mark L. Mcconnell, Peter F. Bloser, G L. Case, M L. Cherry, J Cravens, T G. Guzik, K Hurley, R M. Kippen, John R. Macri, R S. Miller, W Paciesas, James M. Ryan, B Schaefer, J G. Stacy, W T. Vestrand, J P. Wefel

Space Science Center

The primary scientific mission of the Black Hole Finder Probe (BHFP), part of the NASA Beyond Einstein program, is to survey the local Universe for black holes over a wide range of mass and accretion rate. One approach to such a survey is a hard X‐ray coded‐aperture imaging mission operating in the 10–600 keV energy band. The development of new inorganic scintillator materials provides improved performance that is well suited to the BHFP science requirements. Detection planes formed with these materials coupled with a new generation of readout devices represent a major advancement in the performance capabilities of scintillator‐based gamma …

Simulated Performance Of 3-Dti Gamma-Ray Telescope Concepts, Peter F. Bloser, Mark L. Mcconnell, James M. Ryan, Louis M. Barbier, Alan Centa, Stanley D. Hunter, John F. Krizmanic, Jason T. Link, Geoergia A. De Nolfo, Seunghee Son

Space Science Center

We present Monte Carlo simulations of two astronomical gamma-ray telescope concepts based on the ThreeDimensional Track Imager (3- DTI) detector. The 3-DTI consists of a time projection chamber with two-dimensional, crossedstrip micro-well detector readout. The full three- dimensional reconstruction of charged-particle tracks in the gas volume is obtained from transient digitizers, which record the time signature of the charge collected in the wells of each strip. Such detectors hold great promise for advanced Compton telescope (ACT) and advanced pair telescope (APT) concepts due to the very precise measurement of charged particle momenta that is possible (Compton recoil electrons and electron-positron …

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.

Peak Oil, Geopolitics And The Need For Relocalization: Will Our Magnificent Obsession Become Our Obsolete Obsession?, John E. Carroll

The University Dialogue

This essay will look at the peak oil question, contemporary “oil geopolitics” and their effect not only on energy supplies, but also on transportation, agriculture and food supplies, and population distribution in the United States. While the war in Iraq forms a centerpiece in the geopolitical scene, Russia, China, and other nations will be discussed as well. This essay will also examine the inevitable relocalization which appears to be a necessary result.

Thermal Expansion And Magnetostriction Of The Ising Antiferromagnet Tbni2ge2, G M. Schmiedeshoff, Shawna M. Hollen, S L. Budko, P C. Canfield

Physics & Astronomy

We have measured the linear thermal expansion and magnetostriction of the Ising antiferromagnet TbNi2Ge2 along its c-axis from room temperature to 2 K and in magnetic fields to 14 T. We find a magnetic phase diagram that agrees with earlier work and estimate aspects of its uniaxial pressure dependence. We also find a new high field feature near 10 T which may signal the onset of an additional field-induced phase.