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Now showing items 11-20 of 23
Interactions between mantle plumes and mid-ocean ridges : constraints from geophysics, geochemistry, and geodynamical modeling
(Massachusetts Institute of Technology, 2001)
This thesis studies interactions between mid-ocean ridges and mantle plumes using geophysics, geochemistry, and geodynamical modeling. Chapter 1 investigates the effects of the Marion and Bouvet hotspots on the ultra-slow ...
Zinc and cadmium in benthic foraminifera as tracers of ocean paleochemistry
(Massachusetts Institute of Technology, 2000)
Benthic foraminiferal δ13C, Cd/Ca, and Ba/Ca are important tools for reconstructing nutrient distributions, and thus ocean circulation, on glacial-interglacial timescales. However, each tracer has its own "artifacts" that ...
Mechanisms of turbulent mixing in the Continental Shelf bottom boundary layer
(Massachusetts Institute of Technology, 2000)
The bottom boundary layer is an important dynamical region of shallow water flows. In this thesis, the problem of turbulent mixing in the coastal bottom boundary layer is investigated with a unique set of field measurements ...
Global isotopic signatures of oceanic island basalts / by
(Massachusetts Institute of Technology, 1991)
Sr, Nd and Pb isotopic analyses of 477 samples representing 30 islands or island groups, 3 seamounts or seamount chains, 2 oceanic ridges and 1 oceanic plateau [for a total of 36 geographic features] are compiled to form ...
The evolution of lithospheric deformation and crustal structure from continental margins to oceanic spreading centers
(Massachusetts Institute of Technology, 2002)
This thesis investigates the evolution of lithospheric deformation and crustal structure from continental margins to mid-ocean ridges. The first part (Ch. 2) examines the style of segmentation along the U.S. East Coast ...
Subduction in an eddy-resolving state estimate of the northeast Atlantic Ocean
(Massachusetts Institute of Technology, 2004)
Relatively little is known about the role of eddies in controlling subduction in the eastern half of the subtropical gyre. Here, a new tool to study the eastern North Atlantic Ocean is created by combining a regional, ...
Direct and indirect photoreactions of chromophoric dissolved organic matter : roles of reactive oxygen species and iron
(Massachusetts Institute of Technology, 2002)
Photochemical transformations of chromophoric dissolved organic matter (CDOM) are one of the principal processes controlling its fate in coastal waters. The photochemical decomposition of CDOM leads to the formation of a ...
Enhancement of fine particle deposition to permeable sediments
(Massachusetts Institute of Technology, 2002)
Predictions of deposition rate are integral to the transport of many constituents including contaminants, organic matter, and larvae. Review of the literature demonstrates a general appreciation for the potential control ...
The paleoceanography of the Bering Sea during the last glacial cycle
(Massachusetts Institute of Technology, 2006)
In this thesis, I present high-resolution stable-isotope and planktonic-fauna records from Bering Sea sediment cores, spanning the time period from 50,000 years ago to the present. During Marine Isotope Stage 3 (MIS3) at ...
Biogeochemical applications of compound-specific radiocarbon analysis
(Massachusetts Institute of Technology, 2000)
Compound-specific carbon isotopic (613C and A14C) data are reported for lipid biomarkers isolated from Santa Monica Basin (SMB) and Santa Barbara Basin (SBB) surface sediments. These organic compounds represent phytoplanktonic, ...