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Molecular Biogeochemistry of modern and ancient marine microbes
(Massachusetts Institute of Technology, 2010)
Biological activity has shaped the surface of the earth in numerous ways, but life's most pervasive and persistent global impact has been the secular oxidation of the surface environment. Through primary production - the ...
Laboratory and field-based investigations of subsurface geochemical processes in seafloor hydrothermal systems
(Massachusetts Institute of Technology, 2010)
This thesis presents the results of four discrete investigations into processes governing the organic and inorganic chemical composition of seafloor hydrothermal fluids in a variety of geologic settings. Though Chapters 2 ...
Microbial interactions associated with biofilms attached to Trichodesmium spp. and detrital particles in the ocean
(Massachusetts Institute of Technology, 2010)
Quorum sensing (QS) via acylated homoserine lactones (AHLs) was discovered in the ocean, yet little is known about its role in the ocean beyond its involvement in certain symbiotic interactions. The objectives of this ...
Abyssal mixing from bottom boundary effects in Mid-Atlantic Ridge flank canyons
(Massachusetts Institute of Technology, 2010)
This paper begins to explore a previously neglected mechanism for abyssal ocean mixing using bottom boundary layer dynamics. Abyssal mixing and the associated upward buoyancy fluxes are necessary to balance the sinking of ...
Geomicrobiology of nitrogen in a coastal aquifer : isotopic and molecular methods to examine nitrification and denitrification in groundwater
(Massachusetts Institute of Technology, 2010)
Excess nitrogen input is deleterious to coastal waters, resulting in deterioration of the water quality, increases in harmful algal blooms and disease in commercial fish stocks. A significant portion of this nitrogen enters ...
Coral calcification : insights from inorganic experiments and coral responses to environmental variables
(Massachusetts Institute of Technology, 2010)
The mechanisms involved in the formation of coral skeletons are examined using a laboratory model for coral calcification and the growth of living corals under different environmental conditions. Abiogenic aragonite was ...
Linear and nonlinear stratified spindown over sloping topography
(Massachusetts Institute of Technology, 2010)
In a stratified rotating fluid, frictionally driven circulations couple with the buoyancy field over sloping topography. Analytical and numerical methods are used to quantify the impact of this coupling on the vertical ...
Controls on earthquake rupture and triggering mechanisms in subduction zones
(Massachusetts Institute of Technology, 2010)
Large earthquake rupture and triggering mechanisms that drive seismicity in subduction zones are investigated in this thesis using a combination of earthquake observations, statistical and physical modeling. A comparison ...
Temporal and petrogenetic constraints on volcanic accretionary processes at 9-10 degrees North East Pacific Rise
(Massachusetts Institute of Technology, 2010)
Volcanic accretion at the fast-spreading East Pacific Rise (EPR) occurs over a ~2-4 km wide neo-volcanic zone on either side of the axial summit trough (AST). Eruption ages are critical for understanding the distribution ...