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The temporal dynamics of terrestrial organic matter transfer to the oceans : initial assessment and application
(Massachusetts Institute of Technology, 2007)
This thesis employs compound-specific stable carbon and radiocarbon isotopic analysis of organic biomarkers to (a) resolve petrogenic from pre-aged vascular plant organic carbon (OC) in continental margin sediments, (b) ...
Cross-shelf circulation and momentum and heat balances over the inner continental shelf near Martha's Vineyard, Massachusetts
(Massachusetts Institute of Technology, 2007)
The water circulation and evolution of water temperature over the inner continental shelf are investigated using observations of water velocity, temperature, density, and bottom pressure; surface gravity waves; wind stress; ...
Seismic and gravitational studies of melting in the mantle's thermal boundary layers
(Massachusetts Institute of Technology, 2007)
This thesis presents three studies which apply geophysical tools to the task of better understanding mantle melting phenomena at the upper and lower boundaries of the mantle. The first study uses seafloor bathymetry and ...
A determination of air-sea gas exchange and upper ocean biological production from five noble gasses and tritiugenic helium-3
(Massachusetts Institute of Technology, 2007)
The five noble gases (helium, neon, argon, krypton, and xenon) are biologically and chemically inert, making them ideal oceanographic tracers. Additionally, the noble gases have a wide range of solubilities and molecular ...
Experimental and seismological constraints on the rheology, evolution, and alteration of the lithosphere at oceanic spreading centers
(Massachusetts Institute of Technology, 2007)
Oceanic spreading centers are sites of magmatic, tectonic, and hydrothermal processes. In this thesis I present experimental and seismological constraints on the evolution of these complex regions of focused crustal accretion ...
The marine biogeochemistry of zinc isotopes
(Massachusetts Institute of Technology, 2007)
Zinc (Zn) stable isotopes can record information about important oceanographic processes. This thesis presents data on Zn isotopes in anthropogenic materials, hydrothermal fluids and minerals, cultured marine phytoplankton, ...
Geomicrobiology of the ocean crust : the phylogenetic diversity, abundance, and distribution of microbial communities inhabiting basalt and implications for rock alteration processes
(Massachusetts Institute of Technology, 2007)
Basaltic ocean crust has the potential to host one of the largest endolithic communities on Earth. This portion of the biosphere, however, remains largely unexplored. In this study, we utilize molecular biological, ...
Geochemistry of slow-growing corals : reconstructing sea surface temperature, salinity and the North Atlantic Oscillation
(Massachusetts Institute of Technology, 2007)
A 225-year old coral from the south shore of Bermuda (64°W, 320N) provides a record of decadal-to-centennial scale climate variability. The coral was collected live, and sub-annual density bands seen in x-radiographs ...
Oceanic lithosphere magnetization : marine magnetic investigations of crustal accretion and tectonic processes in mid-ocean ridge environments
(Massachusetts Institute of Technology, 2007)
The origin of symmetric alternating magnetic polarity stripes on the seafloor is investigated in two marine environments; along the ridge axis of the fast spreading East Pacific Rise (EPR) (90 25'-90 55'N) and at Kane ...
Geochemical and rheological constraints on the dynamics of the oceanic upper mantle
(Massachusetts Institute of Technology, 2007)
I provide constraints on mantle convection through observations of the rheology and composition of the oceanic upper mantle. Convection cannot be directly observed, yet is a fundamental part of the plate tectonic cycle. ...