Search
Now showing items 61-70 of 71
The biogeochemistry of lipid derived infochemical signals in the ocean
(Massachusetts Institute of Technology, 2016)
The role of oxylipins in ocean biogeochemistry was investigated using microcosm amendment experiments, environmental lipidomics, and culture based studies. Oxylipins are a bioactive class of secondary metabolites produced ...
Variations in coral reef net community calcification and aragonite saturation state on local and global scales
(Massachusetts Institute of Technology, 2013)
Predicting the response of net community calcification (NCC) to ocean acidification OA and declining aragonite saturation state [Omega]a requires a thorough understanding of controls on NCC. The diurnal control of light ...
Carbon and mineral transformations in seafloor serpentinization systems
(Massachusetts Institute of Technology, 2018)
This thesis examines abiotic processes controlling the transformation and distribution of carbon compounds in seafloor hydrothermal systems hosted in ultramafic rock. These processes have a direct impact on carbon budgets ...
Amundsen Sea sea-ice variability, atmospheric circulation, and spatial variations in snow isotopic composition from new West Antarctic firn cores
(Massachusetts Institute of Technology, 2014)
Recent work has documented dramatic changes in the West Antarctic Ice Sheet (WAIS) over the past 30 years (e.g., mass loss, glacier acceleration, surface warming) due largely to the influence of the marine environment. ...
Lithospheric dynamics of Earth's subduction zones and Martian tectonic provinces
(Massachusetts Institute of Technology, 2015)
This thesis investigates lithospheric dynamics of Earth's subduction zones and Martian tectonic provinces on multiple time scales ranging from short-term earthquake deformation to long-term tectonic loading. In Chapter 2, ...
Quantifying overwash flux in barrier systems : an example from Martha's Vineyard, Massachusetts, USA
(Massachusetts Institute of Technology, 2011)
Coastal barriers are particularly susceptible to the predicted effects of accelerated of sea-level rise and the potential for increased impacts of intense storms. Over centennial scales, barriers are maintained via overtopping ...
Aridification of the Indian subcontinent during the Holocene : implications for landscape evolution, sedimentation, carbon cycle, and human civilizations
(Massachusetts Institute of Technology, 2012)
The Indian monsoon affects the livelihood of over one billion people. Despite the importance of climate to society, knowledge of long-term monsoon variability is limited. This thesis provides Holocene records of monsoon ...
The cobalt cycle in the tropical Pacific Ocean
(Massachusetts Institute of Technology, 2017)
Although over a dozen elements are needed to support phytoplankton growth, only a few are considered to be growth-limiting. As the central atom in vitamin B12, cobalt is crucial for metabolism, but its status as a limiting ...
The geochemistry of methane isotopologues
(Massachusetts Institute of Technology, 2017)
This thesis documents the origin, distribution, and fate of methane and several of its isotopic forms on Earth. Using observational, experimental, and theoretical approaches, I illustrate how the relative abundances of ...
The marine biogeochemistry of chromium isotopes
(Massachusetts Institute of Technology, 2018)
In the ocean, chromium (Cr) is a redox-sensitive trace metal. The reduction of Cr(VI) to Cr(III) occurs in oxygen deficient zones (ODZs), and Cr reduction in general has been identified as a significant Cr isotope fractionation ...