Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2013. / "June 2013." Cataloged from PDF version of thesis. / Includes bibliographical references (pages 37-41). / Intraplate faulting in central Asia is a major component of the Indo-Eurasian collision. The kinematics and mechanisms of intraplate deformation are important in understanding broad active tectonic patterns, reconstructing past tectonics, analyzing seismic hazard and identifying potential resources. We examine the fault kinematics surrounding the 150 km wide Shargyn Basin at the intersection of the left-lateral transpressional Gobi-Altai fault system and the right-lateral transpressional Altai fault system. The studies were performed using satellite data and targeted field transects. The results suggest the Shargyn basin is formed by a compressional stepover, an uplifted wedge from the intersecting strike-slip systems and many strike-slip terminating thrust splays. Furthermore, local foliation is almost always fault parallel, pointing to the importance of pre-existing structural weaknesses in the development of active faults. This research demonstrates some of the potential kinematics for intraplate transpressional orogenies and emphasizes the importance of pre-existing crustal structure in the development of active faults. / by Thomas Ben Thompson. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1985. / Microfiche copy available in Archives and Science. / Includes bibliographies. / by Stephanie Louise Pfirman. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1991. / Includes bibliographical references (p. 208-224). / by Anne Frances Sheehan. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1990. / Accompanied by one map on folded leaf in pocket. / Includes bibliographical references (p. 56-61). / by S. Julio Friedmann. / M.S.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 77-81). / Tropical cyclones are known to cause phytoplankton blooms in regions of the ocean that would otherwise support very little life; it is also known that these storms entrain carbon-rich deep water, which can cause locally-significant air-sea fluxes. However, the relative magnitude of these two processes has mostly not been established, and questions about their global impact on the carbon cycle remain. A high-resolution model is developed, using established techniques and tabulated and published inputs, which tracks the physical, chemical, and biological evolution of the ocean's mixed layer in response to atmospheric forcing. Its ability to recreate the observed ocean state is tested. This model is used to simulate a real region of ocean, both with and without the mixing induced by a tropical cyclone, in order to find the change in biological activity and carbon content, and to track the evolution of this anomaly through the end of the winter. After carefully examining a few specific cases that have been discussed in previous literature, one calendar year's worth of storms are modeled, and their net effect is summarized. It is shown that many storms do enhance biological productivity, but only in a few rare cases does the amount of carbon sunk by phytoplankton decay exceed the amount mixed upward by the entrainment of cold, carbon-rich water. The sign of the storm-induced carbon flux is thus shown to be upward for nearly all storms. However, even this effect is small: the net efflux of carbon from the deep ocean to the mixed layer and the atmosphere in the year 2006 is found to be at most on the order of a few tens of teragrams. This is consistent with other studies. / by Neil L. Zimmerman. / S.M.

Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2009. / Cataloged from PDF version of thesis. / Includes bibliographical references (page 36) and index. / The intent of this project was to determine the relationship between the number of radial velocity observations of an Earth-twin exoplanet and the error in the mass calculated from the detected signal. If the planet's period is known through prior transit observations, the mass may be measured by radial velocity more accurately; this project tested and measured the conditions for this error reduction. Simulated sets of radial velocity data taken by HARPS (accurate to 1 m/s) for an Earth-mass planet in a circular, edge-on, 1 AU orbit around a Sun-like star were used with a least-squares fit to measure the amplitude of the sinusoidal radial velocity curve. The three conditions in which the mass fit was compared were: evenly-spaced observations with the period unknown; evenly-spaced observations with the period known; and an unevenly-spaced observation method in which observation times are chosen to be very frequent and clustered around the peaks of the radial velocity curve. For evenly-spaced observations, knowledge of the period did not reduce the error in the mass measurement compared to the period-unknown case, though it did allow for the elimination of the false-negative detection case. When observations were evenly spaced, the percent error in the detected mass had a power law relationship with the number of observations of [sigma]%error 1250=N -⁰.⁵. However, when using the knowledge of the period from transits to choose clustered observation times near the peaks of the curve, the error in the mass was reduced by about 20% for the same number of total observations, and was thus approximated by the power law [sigma]%error = 1030N-⁰.⁵. This indicates that if the period of a low-mass planet is known through transits, the use of clustered observations allows its mass to be measured more accurately with the same number of radial velocity observations than if the period were unknown. / by Allison L. Moberger. / S.B.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1984. / Microfiche copy available in Archives and Science. / Bibliography: leaf 40. / by James Louis Franklin. / M.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1996. / Includes bibliographical references (p. 270-284). / by Matthias Georg Imhof. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2016. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 21-26). / The Avalon terrane in Newfoundland includes the Ediacaran Gaskiers Formation, which has been associated with a Snowball glaciation event. The complicated regional stratigraphy and lack of precise geochronological constraints has made it difficult to determine the spatial and temporal extent of the Gaskiers glaciation. Recent recognition of a diamictite facies on the nearby Bonavista Peninsula correlative with the Gaskiers diamictite has allowed for new, high-precision geochronological constraints on the Gaskiers glaciation and constrains the duration of the event to less than 390 ±320 kyr. The Snowball Earth hypothesis requires that glaciation continued for several millions of years so that CO2 could build up to high enough levels in the atmosphere for catastrophic deglaciation; the short duration of the Gaskiers event makes it unlikely to have been a Snowball event. Further geochronological studies are needed to determine whether the Gaskiers glaciation was a discrete event or if it was a glacial maximum in a longer Ediacaran ice age. / by Judy Pu. / S.B.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1991. / Includes bibliographical references (leaves 173-182). / by Jeffrey A. Meredith. / Sc.D.