Now showing items 363-382 of 1068

    • Fine-scale seismic structure of the shallow volcanic crust on the East Pacific Rise at 9°50′N 

      Sohn, Robert A.; Webb, Spahr C.; Hildebrand, John A. (American Geophysical Union, 2004-12-09)
      We use a combination of body wave and interface wave observations from an on-bottom seismic refraction survey to constrain the fine-scale seismic structure of the upper crust in a ∼3 × 3 km field area centered on the East ...
    • Finite difference modeling of geoacoustic interaction at anelastic seafloors 

      Stephen, Ralph A.; Swift, Stephen A. (Acoustical Society of America, 1994-01)
      A major problem in understanding seismic wave propagation in the seafloor is to distinguish between the loss of energy due to intrinsic attenuation and the loss of energy due to scattering from fine scale heterogeneities ...
    • Fire history of a giant African baobab evinced by radiocarbon dating 

      Patrut, Adrian; Mayne, Diana H.; von Reden, Karl F.; Lowy, Daniel A.; van Pelt, Robert; McNichol, Ann P.; Roberts, Mark L.; Margineanu, Dragos (Dept. of Geosciences, University of Arizona, 2010-08)
      The article reports the first radiocarbon dating of a live African baobab (Adansonia digitata L.), by investigating wood samples collected from 2 inner cavities of the very large 2-stemmed Platland tree of South Africa. ...
    • Florida Current surface temperature and salinity variability during the last millennium 

      Lund, David C.; Curry, William B. (American Geophysical Union, 2006-05-05)
      The salinity and temperature of the Florida Current are key parameters affecting the transport of heat into the North Atlantic, yet little is known about their variability on centennial time scales. Here we report replicated, ...
    • Florida Straits density structure and transport over the last 8000 years 

      Lynch-Stieglitz, Jean; Curry, William B.; Lund, David C. (American Geophysical Union, 2009-09-01)
      The density structure across the Florida Straits is reconstructed for the last 8000 years from oxygen isotope measurements on foraminifera in sediment cores. The oxygen isotope measurements suggest that the density contrast ...
    • Flow and sediment properties influencing erosion of fine-grained marine sediments : sea floor and laboratory experiments 

      Young, Robert Alexander (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1975-09)
      Erosion processes involving fine-grained marine sediments were studied by using an in situ flume to erode undisturbed bottom sediments on the sea floor in Buzzards Bay, a shallow marine embayment off the Massachusetts coast. ...
    • Flow and skin friction over natural rough beds 

      Paola, Christopher (Woods Hole Oceanographic Institution, 1983-06)
      The first of two sets of data reported here, measured over two-dimensional immobile current ripples, comprises skin-friction time series at four streamwise positions and velocity profiles measured to within a few mm of ...
    • Fluid flow and sound generation at hydrothermal vent fields 

      Little, Sarah A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1988-04-08)
      Several experiments are presented in this thesis which examine methods to measure and monitor fluid flow from hydrothermal vent fields. Simultaneous velocity, temperature, and conductivity data were collected in the ...
    • Flux measurements of explosive degassing using a yearlong hydroacoustic record at an erupting submarine volcano 

      Dziak, Robert P.; Baker, Edward T.; Shaw, Alison M.; Bohnenstiehl, DelWayne R.; Chadwick, William W.; Haxel, Joseph H.; Matsumoto, Haru; Walker, Sharon L. (American Geophysical Union, 2012-11-29)
      The output of gas and tephra from volcanoes is an inherently disorganized process that makes reliable flux estimates challenging to obtain. Continuous monitoring of gas flux has been achieved in only a few instances at ...
    • Fluxes, dynamics and chemistry of particulates in the ocean 

      Gardner, Wilford D. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1977-10)
      Sediment traps designed to yield quantitative data of particulate fluxes have been deployed and successfully recovered on four moorings in the deep sea. The traps were designed after extensive calibration of different ...
    • Focusing of upward fluid migration beneath volcanic arcs : effect of mineral grain size variation in the mantle wedge 

      Wada, Ikuko; Behn, Mark D. (John Wiley & Sons, 2015-11-13)
      We use numerical models to investigate the effects of mineral grain size variation on fluid migration in the mantle wedge at subduction zones and on the location of the volcanic arc. Previous coupled thermal-grain size ...
    • Formation of submarine lava channel textures : insights from laboratory simulations 

      Garry, W. Brent; Gregg, Tracy K. P.; Soule, Samuel A.; Fornari, Daniel J. (American Geophysical Union, 2006-03-28)
      Laboratory simulations using polyethylene glycol (PEG) extruded at a constant rate and temperature into a tank with a uniform basal slope and filled with a cold sucrose solution generate channels that are defined by ...
    • Four hydrophone array for acoustic three-dimensional location 

      Watkins, William A.; Schevill, William E. (Woods Hole Oceanographic Institution, 1971-10)
      This report describes a non-rigid, floating, four-hydrophone array that can give accurate three-dimensional locations for certain underwater sound sources, particularly for those that are close. For more distant sounds, ...
    • FOZO, HIMU, and the rest of the mantle zoo 

      Stracke, Andreas; Hofmann, Albrecht W.; Hart, Stanley R. (American Geophysical Union, 2005-05-19)
      The parameter μ describes the 238U/204Pb ratio of an Earth reservoir. Mantle domains labeled HIMU (high μ) originally defined reservoirs with highly radiogenic Pb isotope ratios observed in basalts from a select number of ...
    • Fracture propagation to the base of the Greenland Ice Sheet during supraglacial lake drainage 

      Das, Sarah B.; Joughin, Ian; Behn, Mark D.; Howat, Ian M.; King, Matt A.; Lizarralde, Daniel; Bhatia, Maya P. (2008-02-20)
      Surface meltwater that reaches the base of an ice sheet creates a mechanism for the rapid response of ice flow to climate change. The process whereby such a pathway is created through thick, cold ice has not, however, ...
    • Frictional behavior of oceanic transform faults and its influence on earthquake characteristics 

      Liu, Yajing; McGuire, Jeffrey J.; Behn, Mark D. (American Geophysical Union, 2012-04-26)
      We use a three-dimensional strike-slip fault model in the framework of rate and state-dependent friction to investigate earthquake behavior and scaling relations on oceanic transform faults (OTFs). Gabbro friction data ...
    • Frozen magma lenses below the oceanic crust 

      Nedimovic, Mladen R.; Carbotte, Suzanne M.; Harding, Alistair J.; Detrick, Robert S.; Canales, J. Pablo; Diebold, John B.; Kent, Graham M.; Tischer, Michael; Babcock, Jeffrey M. (2005-06-15)
      The Earth's oceanic crust crystallizes from magmatic systems generated at mid-ocean ridges. Whereas a single magma body residing within the mid-crust is thought to be responsible for the generation of the upper oceanic ...
    • Future of the NOSAMS Tandetron AMS system 

      von Reden, Karl F. (2009-04-13)
      The NOSAMS 3 MV Tandetron AMS system will soon reach its 20th anniversary of operation. A critical review of all aspects of the system is necessary to assess the analytical, economic, and operational factors that enter ...
    • A gas-accepting ion source for Accelerator Mass Spectrometry : progress and applications 

      Roberts, Mark L.; von Reden, Karl F.; Burton, Joshua R.; McIntyre, Cameron P.; Beaupre, Steven R. (2011-10-31)
      The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at the Woods Hole Oceanographic Institution has developed an Accelerator Mass Spectrometry (AMS) system designed specifically for the analysis of ...
    • Gene expression in the deep biosphere 

      Orsi, William D.; Edgcomb, Virginia P.; Christman, Glenn D.; Biddle, Jennifer F. (2013-04-23)
      Scientific ocean drilling has revealed a deep biosphere of widespread microbial life in sub-seafloor sediment. Microbial metabolism in the marine subsurface likely plays an important role in global biogeochemical cycles1-3 ...