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Biogeochemical and phylogenetic signals of Proterozoic and Phanerozoic microbial metabolisms
(Massachusetts Institute of Technology, 2018)
Life is ubiquitous in the environment and an important mediator of Earth's carbon cycle, but quantifying the contribution of microbial biomass and its metabolic fluxes is difficult, especially in spatially and temporally-remote ...
Seismic constraints on the processes and consequences of secondary igneous evolution of Pacific oceanic lithosphere
(Massachusetts Institute of Technology, 2016)
This thesis examines the structure of Pacific oceanic lithosphere that has been modified by post-formation magmatism in order to better understand the processes of secondary magmatic evolution of the lithosphere, which can ...
A magmatic trigger for the Paleocene-Eocene thermal maximum?
(Massachusetts Institute of Technology, 2015)
Fifty-six million years ago Earth experienced rapid global warming (~6°C) that was caused by the release of large amounts of carbon into the ocean-atmosphere system. This Paleocene-Eocene Thermal Maximum (PETM) is often ...
Trace element proxies and mineral indicators of hydrothermal fluid composition and seafloor massive sulfide deposit formation processes
(Massachusetts Institute of Technology, 2017)
This thesis analyzes compositions of seafloor massive sulfide (SMS) deposits and related hydrothermal vent fluids to identify proxies of reaction zone conditions (host-rock lithology, hydrothermal fluid temperature and ...
Chaotic advection, mixing, and property exchange in three-dimensional ocean eddies and gyres
(Massachusetts Institute of Technology, 2018)
This work investigates how a Lagrangian perspective applies to models of two oceanographic flows: an overturning submesoscale eddy and the Western Alboran Gyre. In the first case, I focus on the importance of diffusion as ...
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 ...
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 ...
Temporal variability in chemical cycling of the subterranean estuary and associated chemical loading to the coastal ocean
(Massachusetts Institute of Technology, 2014)
At the land-ocean interface, terrestrial groundwater interacts with seawater to form a subterranean estuary, which can play host to dynamic biogeochemical cycling of nutrients, trace metals and radionuclides. This chemically ...
Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles
(Massachusetts Institute of Technology, 2017)
Particulate organic carbon (POC) in the ocean and mobilized by rivers on land transfers -0. 1% of global primary productivity to the deep ocean sediments. This small fraction regulates the long-term carbon cycle by removing ...
Buoyancy-driven circulation in the Red Sea
(Massachusetts Institute of Technology, 2014)
This thesis explores the buoyancy-driven circulation in the Red Sea, using a combination of observations, as well as numerical modeling and analytical method. The first part of the thesis investigates the formation mechanism ...