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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 ...
Theory and application of source independent full wavefield elastic converted phase seismic imaging and velocity analysis
(Massachusetts Institute of Technology, 2015)
The recorded seismic signal contains full information about the source that generated the seismic waves and the path along which the seismic waves travel and interfere with subsurface. However, source information is not ...
Ambient noise tomography for wavespeed and anisotropy in the crust of southwestern China
(Massachusetts Institute of Technology, 2014)
The primary objective of this thesis is to improve our understanding of the crustal structure and deformation in the southeastern Tibetan Plateau and adjacent regions using surface wave tomography. Green's functions for ...
Geophysical insights into the histories of Venus, Mercury and the Moon
(Massachusetts Institute of Technology, 2014)
Gravity and topography data provide a powerful tool for studying the interiors of rocky planetary bodies. In this thesis I study three such bodies - Venus, Mercury and the Moon - and I use the gravity and topography data ...
Molecular determination of marine iron ligands by mass spectrometry
(Massachusetts Institute of Technology, 2016)
Marine microbes produce a wide variety of metal binding organic ligands that regulate the solubility and availability of biologically important metals such as iron, copper, cobalt, and zinc. In marine environments where ...
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 ...
Linking microbial metabolism and organic matter cycling through metabolite distributions in the ocean
(Massachusetts Institute of Technology, 2017)
Key players in the marine carbon cycle are the ocean-dwelling microbes that fix, remineralize, and transform organic matter. Many of the small organic molecules in the marine carbon pool have not been well characterized ...
Geochemical controls on the distribution and composition of biogenic and sedimentary carbon
(Massachusetts Institute of Technology, 2017)
Organic carbon (OC) preserved in marine sediments acts as a reduced carbon sink that balances the global carbon cycle. Understanding the biogeochemical mechanisms underpinning the balance between OC preservation and ...
Cyanobacterial evolution and interactions with the Proterozoic world
(Massachusetts Institute of Technology, 2020)
Our understanding of the biosphere prior to the rise of complex life is built largely upon microbial mat structures and some exceptionally well-preserved microbial fossils from the Proterozoic (2500 to 540 million years ...