Search
Now showing items 61-69 of 69
Scavenging and transport of thorium radioisotopes in the North Atlantic Ocean
(Massachusetts Institute of Technology, 2018)
Many chemical constituents are removed from the ocean by attachment to settling particles, a process referred to as "scavenging." Radioisotopes of thorium, a highly particle-reactive element, have been used extensively to ...
Submesoscale turbulence in the upper ocean
(Massachusetts Institute of Technology, 2016)
Submesoscale flows, current systems 1-100 km in horizontal extent, are increasingly coming into focus as an important component of upper-ocean dynamics. A range of processes have been proposed to energize submesoscale ...
Exploring the climate change refugia potential of equatorial Pacific coral reefs
(Massachusetts Institute of Technology, 2015)
Global climate models project a 21st century strengthening of the Pacific Equatorial Undercurrent (EUC). The consequent increase in topographic upwelling of cool waters onto equatorial coral reef islands would mitigate ...
Radium isotopes as tracers of boundary inputs of nutrients and trace elements to the coastal and open ocean
(Massachusetts Institute of Technology, 2018)
Nutrients and trace metals are vital for supporting life in the ocean, but the boundary processes that control the distributions of these elements are poorly constrained. Radium isotopes are well suited to studying inputs ...
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 ...
Geophysical and geochemical constraints on the evolution of oceanic lithosphere from formation to subduction
(Massachusetts Institute of Technology, 2017)
This thesis investigates the evolution of the oceanic lithosphere in a broad sense from formation to subduction, in a focused case at the ridge, and in a focused case proximal to subduction. In general, alteration of the ...
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. ...
Insight into chemical, biological, and physical processes in coastal waters from dissolved oxygen and inert gas tracers
(Massachusetts Institute of Technology, 2017)
In this thesis, I use coastal measurements of dissolved O₂ and inert gases to provide insight into the chemical, biological, and physical processes that impact the oceanic cycles of carbon and dissolved gases. Dissolved ...
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 ...