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Now showing items 1-10 of 14
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 ...
The biogeochemistry of marine particulate trace metals
(Massachusetts Institute of Technology, 2014)
Marine particles include all living and non-living solid components of seawater, representing an extremely dynamic and chemically diverse mixture of phases. The distributions of these phases are poorly constrained and ...
Urea and nickel utilization in marine cyanobacteria as evaluated by incubation, proteomic, and uptake techniques
(Massachusetts Institute of Technology, 2013)
Nitrogen and trace metal biogeochemical effects on phytoplankton productivity were compared through whole water bottle incubations and proteomic evaluation of in situ harvested particulate matter from two distinct oceanographic ...
Seasonal and interannual variability in the hydrology and geochemistry of an outlet glacier of the Greenland Ice Sheet
(Massachusetts Institute of Technology, 2016)
In the spring and summer within the ablation zone of the Greenland Ice Sheet (GrIS), meltwater drains to the ice sheet bed through an evolving network of efficient channelized and inefficient distributed drainage systems. ...
The marine biogeochemistry of dissolved and colloidal iron
(Massachusetts Institute of Technology, 2013)
Iron is a redox active trace metal micronutrient essential for primary production and nitrogen acquisition in the open ocean. Dissolved iron (dFe) has extremely low concentrations in marine waters that can drive phytoplankton ...
Late Quaternary climate variability and terrestrial carbon cycling in tropical South America
(Massachusetts Institute of Technology, 2016)
Characterizing global and regional climate variability and climate-carbon cycle interactions in the past provides critical context for evaluating present and future climate trends. In this thesis, I use stable isotope and ...
Distribution of thiols in the northwest Atlantic Ocean
(Massachusetts Institute of Technology, 2013)
Thiol substances can form stable complexes with metals (especially copper and mercury) in the surface ocean that can impact cycling and bioavailability of those elements. In this study, I present seven concentration profiles ...
Geochemistry of deep-sea hydrothermal vent fluids from the Mid-Cayman Rise, Caribbean Sea
(Massachusetts Institute of Technology, 2015)
This thesis examines the controls on organic, inorganic, and volatile species distributions in hydrothermal fluids venting at Von Damm and Piccard, two recently discovered vent fields at the ultra slow spreading Mid-Cayman ...
Testing the ancient marine redox record from oxygenic photosynthesis to photic zone euxina
(Massachusetts Institute of Technology, 2015)
Tracing the evolution of Earth's redox history is one of the great challenges of geobiology and geochemistry. The accumulation of photosynthetically derived oxygen transformed the redox state of Earth's surface environments, ...
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 ...