Now showing items 41-60 of 1216

    • Analysis of Deep Seafloor Arrivals observed on NPAL04 

      Stephen, Ralph A.; Bolmer, S. Thompson; Udovydchenkov, Ilya A.; Dzieciuch, Matthew A.; Worcester, Peter F.; Andrew, Rex K.; Mercer, James A.; Colosi, John A.; Howe, Bruce M. (Woods Hole Oceanographic Institution, 2012-12)
      This report gives an overview of the analysis that was done on Deep Seafloor Arrivals since they were initially presented in Stephen et al (2009). All of the NPAL04/LOAPEX (North Pacific Acoustic Laboratory, 2004/ Long ...
    • Analysis of high-precision vanadium isotope ratios by medium resolution MC-ICP-MS 

      Nielsen, Sune G.; Owens, Jeremy D.; Horner, Tristan J. (2015-11)
      We present and verify a new method to measure vanadium isotope ratios using a Thermo Scientific Neptune multi-collector inductively-coupled plasma mass spectrometer (MCICP- MS) operated in medium mass resolution mode. ...
    • Analysis of seafloor seismograms of the 2003 Tokachi-Oki earthquake sequence for earthquake early warning 

      McGuire, Jeffrey J.; Simons, Frederik J.; Collins, John A. (American Geophysical Union, 2008-07-31)
      Earthquake Early Warning (EEW) algorithms estimate the magnitude of an underway rupture from the first few seconds of the P-wave to allow hazard assessment and mitigation before the S-wave arrival. Many large subduction-zone ...
    • Analysis of stable sulfur isotopes and trace cobalt on sulfides from the TAG hydrothermal mound 

      Friedman, Carrie T. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998-02)
      Stable sulfur isotopes (δ34S) and trace Co are analyzed in sulfide and sulfate minerals from six sample types collected from the TAG active mound, 26°N Mid-Atlantic Ridge. δ34S values range from 2.7 to 2O.9%, with sulfate ...
    • Anatomy of an active submarine volcano 

      Arnulf, Adrien F.; Harding, Alistair J.; Kent, Graham M.; Carbotte, Suzanne M.; Canales, J. Pablo; Nedimovic, Mladen R. (2014-05)
      Most of the magma erupted at mid-ocean ridges is stored in a mid-crustal melt lens that lies at the boundary between sheeted dikes and gabbros. Nevertheless, images of the magma pathways linking this melt lens to the ...
    • And on top of all that… coping with ocean acidification in the midst of many stressors 

      Breitburg, Denise L.; Salisbury, Joseph E.; Bernhard, Joan M.; Cai, Wei-Jun; Dupont, Sam; Doney, Scott C.; Kroeker, Kristy J.; Levin, Lisa A.; Long, W. Christopher; Milke, Lisa M.; Miller, Seth H.; Phelan, Beth; Passow, Uta; Seibel, Brad A.; Todgham, Anne E.; Tarrant, Ann M. (The Oceanography Society, 2015-06)
      Oceanic and coastal waters are acidifying due to processes dominated in the open ocean by increasing atmospheric CO2 and dominated in estuaries and some coastal waters by nutrient-fueled respiration. The patterns and ...
    • Anisotropy and the structural evolution of the oceanic upper mantle 

      Forsyth, Donald W. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1973-09)
      The dispersion of Love and Rayleigh waves in the period range 17-167 sec. is used to detect the change in the structure of the upper mantle as the age of the sea-floor increases away from the mid-ocean ridge. Using the ...
    • Anisotropy in seafloor flange, slab, and crust samples from measurements of permeability and porosity : implications for fluid flow and deposit evolution 

      Gribbin, Jill L.; Zhu, Wenlu; Tivey, Margaret K. (American Geophysical Union, 2012-03-21)
      Seafloor hydrothermal vents accommodate the convective transfer of fluids from subsurface environments to the oceans. In addition to black smoker chimneys, a variety of other deposit-types form. Flanges protrude from the ...
    • Anomalous porosity preservation and preferential accumulation of gas hydrate in the Andaman accretionary wedge, NGHP-01 site 17A 

      Rose, Kelly K.; Johnson, Joel E.; Torres, Marta E.; Hong, Wei-Li; Giosan, Liviu; Solomon, Evan A.; Kastner, Miriam; Cawthern, Thomas; Long, Philip E.; Schaef, H. Todd (Elsevier, 2014-06-06)
      In addition to well established properties that control the presence or absence of the hydrate stability zone, such as pressure, temperature, and salinity, additional parameters appear to influence the concentration of gas ...
    • Antarctic glacial chronology : new constraints from surface exposure dating 

      Ackert, Robert P. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000-06)
      Surface exposure dating, using the concentration of cosmogenic nuclides (3He, 21Ne, and 36Cl) in moraine boulders, combined with mapping of glacial moraines from three key locations, is used to provide new constraints ...
    • Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years 

      Howe, Jacob N. W.; Piotrowski, Alexander M.; Oppo, Delia W.; Huang, Kuo-Fang; Mulitza, Stefan; Chiessi, Cristiano M.; Blusztajn, Jerzy S. (John Wiley & Sons, 2016-10-05)
      Antarctic Intermediate Water is an essential limb of the Atlantic meridional overturning circulation that redistributes heat and nutrients within the Atlantic Ocean. Existing reconstructions have yielded conflicting results ...
    • Antarctic sediment chronology by programmed-temperature pyrolysis : methodology and data treatment 

      Rosenheim, Brad E.; Day, Mary Beth; Domack, Eugene; Schrum, Heather; Benthien, Albert; Hayes, John M. (American Geophysical Union, 2008-04-02)
      We report a detailed programmed-temperature pyrolysis/combustion methodology for radiocarbon (14C) dating of Antarctic sub-ice shelf sediments. The method targets the autochthonous organic component in sediments that contain ...
    • Antarctic surface melting dynamics : enhanced perspectives from radar scatterometer data 

      Trusel, Luke D.; Frey, Karen E.; Das, Sarah B. (American Geophysical Union, 2012-05-17)
      Antarctic ice sheet surface melting can regionally influence ice shelf stability, mass balance, and glacier dynamics, in addition to modulating near-surface physical and chemical properties over wide areas. Here, we ...
    • Antarctic-wide array of high-resolution ice core records reveals pervasive lead pollution began in 1889 and persists today 

      McConnell, Joseph R.; Maselli, Olivia J.; Sigl, Michael; Vallelonga, P.; Neumann, T.; Anschutz, H.; Bales, R. C.; Curran, M. A. J.; Das, Sarah B.; Edwards, R.; Kipfstuhl, Sepp; Layman, Lawrence; Thomas, E. R. (Nature Publishing Group, 2014-07-28)
      Interior Antarctica is among the most remote places on Earth and was thought to be beyond the reach of human impacts when Amundsen and Scott raced to the South Pole in 1911. Here we show detailed measurements from an ...
    • Anthropogenic controls on overwash deposition : evidence and consequences 

      Rogers, Laura J.; Moore, Laura J.; Goldstein, Evan B.; Hein, Christopher J.; Lorenzo-Trueba, Jorge; Ashton, Andrew D. (John Wiley & Sons, 2015-12-29)
      Accelerated sea level rise and the potential for an increase in frequency of the most intense hurricanes due to climate change threaten the vitality and habitability of barrier islands by lowering their relative elevation ...
    • Application of an inverse method to interpret 231Pa/230Th observations from marine sediments 

      Burke, Andrea; Marchal, Olivier; Bradtmiller, Louisa I.; McManus, Jerry F.; Francois, Roger (American Geophysical Union, 2011-03-16)
      Records of 231Pa/230Th from Atlantic sediments have been interpreted to reflect changes in ocean circulation during the geologic past. Such interpretations should be tested with due regard to the limited spatial coverage ...
    • Application of secondary ion mass spectrometry to the determination of Mg/Ca in rare, delicate, or altered planktonic foraminifera : examples from the Holocene, Paleogene, and Cretaceous 

      Bice, Karen L.; Layne, Graham D.; Dahl, Kristina A. (American Geophysical Union, 2005-12-23)
      Secondary ion mass spectrometry (SIMS) is useful for measuring Mg/Ca in both primary calcite and diagenetic minerals in planktonic foraminifera. The excellent spatial resolution (<10 μm) and small amount of material removed ...
    • Applications of proxy system modeling in high resolution paleoclimatology 

      Evans, Michael N.; Tolwinski-Ward, S. E.; Thompson, D. M.; Anchukaitis, Kevin J. (Elsevier B.V., 2013-05-29)
      A proxy system model may be defined as the complete set of forward and mechanistic processes by which the response of a sensor to environmental forcing is recorded and subsequently observed in a material archive. Proxy ...
    • Applications of time series analysis to geophysical data 

      Chave, Alan D. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1980-06)
      This thesis consists of three papers applying the techniques of time series analysis to geophysical data. Surface wave dispersion along the Walvis Ridge, South Atlantic Ocean, is obtained by bandpass filtering the ...
    • Arc magmas sourced from melange diapirs in subduction zones 

      Marschall, Horst R.; Schumacher, John C. (2012-10-11)
      At subduction zones, crustal material is recycled back into the mantle. A certain proportion, however, is returned to the overriding plate via magmatism. The magmas show a characteristic range of compositions that have ...