Search
Now showing items 71-80 of 654
Evolution of enriched mantle from derivative basalt, peridotite and diamond inclusion geochemistry
(Massachusetts Institute of Technology, 1984)
Constraining North Atlantic circulation with transient tracer observations
(Massachusetts Institute of Technology, 2003)
The capability of transient tracers to constrain the ocean circulation in the North Atlantic is explored. Study of an idealized tracer shows that inferences of circulation properties from transient state distributions are ...
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 ...
The influence of core crystallization and mantle overturn on ancient dynamos
(Massachusetts Institute of Technology, 2015)
This dissertation contributes to three unresolved problems in planetary science regarding potential dynamo action in asteroids, the Moon, and Mars. First, we examine the physical processes active during asteroid core ...
Laboratory analysis of restrenghtening on simulated faults
(Massachusetts Institute of Technology, 1999)
Seismic data show that stress drop increases with the logarithm of earthquake recurrence interval (1-5 MPa per decade time). If stress drop is taken as a proxy for fault strength, then the data suggest that faults restrengthen ...
Modeling the impact of atmospheric moisture transport on global ice volume
(Massachusetts Institute of Technology, 2004)
Following Milankovitch's original hypothesis most model studies of changes in global ice volume on orbital time scales have focused on the impact of ablation on ice sheet mass balance. In most cases, poleward moisture flux ...
Anisotropy and deformation in the Earth's mantle : seismological observations, geodynamical models, and laboratory experiments
(Massachusetts Institute of Technology, 2006)
In this thesis I report the results of several studies of elastic anisotropy and deformation in the Earth's mantle, using shear wave splitting measurements, numerical models of geodynamical processes, and laboratory ...
Atmospheric propagation effects on radio interferometry
(Massachusetts Institute of Technology, 1986)