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Dynamics of the equatorial undercurrent and its determination
(Massachusetts Institute of Technology, 1988)
This study focuses on the zonal weakening, eastern termination and seasonal variations of the Atlantic equatorial undercurrent (EUC). The main and most original contribution of the dissertation is a detailed analysis of ...
Dismantling the deep earth : geochemical constraints from hotspot lavas for the origin and lengthscales of mantle heterogeneity
(Massachusetts Institute of Technology, 2008)
Chapter 1 presents the first published measurements of Sr-isotope variability in olivine-hosted melt inclusions. Melt inclusions in just two Samoan basalt hand samples exhibit most of the total Sr-isotope variability ...
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, ...
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 ...
Kinetic processes of mantle minerals
(Massachusetts Institute of Technology, 2000)
This dissertation discusses the experimental results designed to constrain the processes of MORB generation. The main focus of this study is to investigate the location and the related processes of the transformation ...
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 ...
Influences on the oceanic biogeochemical cycling of the hybrid-type metals, cobalt, iron, and manganese
(Massachusetts Institute of Technology, 2012)
Trace metal cycling is one of many processes that influence ocean ecosystem dynamics. Cobalt, iron, and manganese are redox active trace metal micro-nutrients with oceanic distributions that are influenced by both biological ...
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 ...
The tectonics and three-dimensional structure of spreading centers--microearthquake studies and tomographic inversions
(Massachusetts Institute of Technology, 1987)
Two-thirds of the Earth's surface has been formed along a global system of spreading centers that are presently manifested in several different structural forms, including the classic rift valley of the Mid-Atlantic Ridge, ...
Organic phosphorus in marine sediments : chemical structure, diagenetic alteration, and mechanisms of preservation
(Massachusetts Institute of Technology, 2000)
Phosphorus, an essential nutrient, is removed from the oceans only through burial with marine sediments. Organic phosphorus (Prog) constitutes an important fraction (ca. 25%) of total-P in marine sediments. However, given ...