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Chemical characterization of dissolved organic matter (DOM) in seawater : structure, cycling, and the role of biology
(Massachusetts Institute of Technology, 2005)
The goal of this thesis is to investigate three different areas relating to the characterization of dissolved organic matter (DOM): further determination of the chemical compounds present in high molecular weight DOM ...
Slip on ridge transform faults : insights from earthquakes and laboratory experiments
(Massachusetts Institute of Technology, 2005)
The relatively simple tectonic environment of mid-ocean ridge transform fault (RTF) seismicity provides a unique opportunity for investigation of earthquake and faulting processes. We develop a scaling model that is complete ...
Tropical climate variability from the last glacial maximum to the present
(Massachusetts Institute of Technology, 2005)
This thesis evaluates the nature and magnitude of tropical climate variability from the Last Glacial Maximum to the present. The temporal variability of two specific tropical climate phenomena is examined. The first is the ...
Molecular and isotopic records of the combustion inputs to the environment over the last 250 yrs
(Massachusetts Institute of Technology, 2004)
The most ubiquitous source of polycyclic aromatic hydrocarbons (PAHs) to the environment is incomplete combustion. This study generated a high-resolution historical record of pyrogenic PAH emissions since pre-industrial ...
The effect of protozoan grazers on the cycling of polychlorinated biphenyls (PCBs) in marine systems
(Massachusetts Institute of Technology, 2000)
Processes affecting organic carbon distribution and composition can control the speciation of organic contaminants such as polychlorinated biphenyls (PCBs) and ultimately determine their residence time in a particular ...
Uranium-series radionuclide records of paleoceanographic and sedimentary changes in the Arctic Ocean
(Massachusetts Institute of Technology, 2009)
The radionuclides ²³¹Pa and ²³⁰Th, produced in the water column and removed from the ocean by particle scavenging and burial in sediments, offer a means for paleoceanographers to examine past dynamics of both water column ...
Radium isotopes as tracers of coastal circulation pathways in the Mid-Atlantic Blight
(Massachusetts Institute of Technology, 2003)
Pathways of exchange between the shelf and slope in the Mid-Atlantic Bight were investigated using a combination of radiochemical tracer and hydrographic measurements. The motivation was to provide evidence of transport ...
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 ...
Geochemical characerization of endmember mantle components
(Massachusetts Institute of Technology, 2005)
This thesis uses trace elements and radiogenic isotope tracers to define elemental abundances in reservoirs of the Earth's mantle, including EM2 (the Enriched Mantle 2), as seen in the Samoan hotspot track, and DMM (the ...
Evaluating mantle and crustal processes using isotope geochemistry
(Massachusetts Institute of Technology, 2000)
Geochemical studies are fundamental for understanding how the dynamic Earth works and evolves. These studies place constraints on the composition, formation, age, distribution, evolution and scales of geochemically distinct ...