Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2005. / Includes bibliographical references (p. 35-38). / The Tso Morari culmination in the Ladakh region of northwest India is a large (>3,000 km²) structural dome cored by coesite-bearing rocks of Indian continental crustal affinity. As one of only two localities in the Himalaya where ultrahigh-pressure rocks have been found, the culmination offers important insights into the orogenic processes responsible for exhumation of subducted continental crust. New, 1:50,000 scale geologic mapping and structural analysis in the Tso Morari area reveals evidence for five distinct deformational events. Rather than simple, one step processes envisioned by investigators in many ultrahigh-pressure terrains, exhumation of the Tso Morari culmination was a polyphase process. From >90 km to mid-crustal depths, exhumation was accommodated by a diachronous set of rooted, ductile, extensional detachments that were active [approx.] 53-40 Ma. Beginning in the Late Oligocene, continued exhumation occurred by progressive unroofing along a younger, brittle-ductile detachment. Through a rolling-hinge mechanism similar to that proposed for many metamorphic core complexes of the North American Cordillera, this unroofing led to the development of the culmination into a NW trending structural dome. / (cont.) More recently, N-S-striking normal faults accommodated continued upper crustal extension throughout much of the remainder of Cenozoic time, despite the culmination's setting in the Himalayan collisional orogen. / by Ryan J. Clark. / S.M.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, and Woods Hole Oceanographic Institution, 1986. / Microfiche copy available in Archives and Science / Bibliography: leaves 145-148. / by Boris Moro. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1994. / Includes bibliographical references (p. 119-124). / by Cecily Jo Wolfe. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 183-187). / A major question for climate studies is to quantify the role of turbulent eddy fluxes in maintaining the observed atmospheric mean state. It has been argued that eddy fluxes keep the mid-latitude atmosphere in a state that is marginally critical to the deepest mode of baroclinic instability, which provides a powerful constraint on the response of the atmosphere to changes in external forcing. A similar criterion does, however not hold in the Southern Ocean, a region whose dynamics are otherwise very similar to the mid-latitude atmosphere. This thesis resolves this apparent contradiction, using a combination of theoretical considerations and eddy-resolving numerical simulations. It is shown that the adjustment of the extra-tropical troposphere to states of marginal criticality does not follow from a fundamental constraint, but is rather the result of the particular parameters characterizing Earth's troposphere. Both marginally critical and strongly supercritical zonal mean flows can be obtained in planetary atmospheres if external parameters are varied. We argue that changes in the equilibrated mean state over a wide range of simulations can better be understood in terms of a balance between the diabatic forcing and the eddy driven overturning circulation. Using a diffusive closure for the eddy flux of potential vorticity, we can relate the eddy-driven overturning transport to properties of the mean flow, and derive scaling relations for both the baroclinicity and vertical stratification of the equilibrated state. / by Malte F. Jansen. / Ph.D.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2016. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 173-181). / This thesis focuses on the source mechanisms of Earthquakes of different scales, from the micro-seismicity in oil/gas fields in Oman, to moderate earthquakes in Kuwait, and finally to pico-seismicity, i.e. acoustic emission, in the laboratory. To investigate the source mechanisms as well as their uncertainties, a waveform-based Bayesian moment tensor inversion approach was developed and validated by synthetic tests. The Bayesian approach estimates the source parameters and the uncertainties by generating a posterior probability density function of the source parameters. The effects of location, velocity model, and error model of the data on the posterior prediction of the source parameters are discussed. This Bayesian moment tensor inversion method was first applied to the well-documented induced seismicity data in an oil/gas field in Oman. On Chapter 3, we move on to another mideast country - Kuwait. We conducted ground motion calculations in Kuwait due to regional large earthquakes and to local seismicity. We found that the regional earthquakes with low-frequency and long-duration surface waves were most likely to affect tall buildings, while the local smaller earthquakes are most likely to affect small and old structures constructed before the adoption of building codes. Using the Bayesian moment tensor inversion method, we studied the source mechanisms of local earthquakes in Kuwait. Historically, Kuwait has low local seismicity; however, in recent years the KNSN has monitored more and more local earthquakes. In 2015, two local earthquakes - Mw4.5 on 03/21/2015 and Mw4.1 on 08/18/2015 - have been recorded by both the Incorporated Research Institutions for Seismology (IRIS) and KNSN, and were widely felt by people in Kuwait. Most earthquakes in Kuwait occurred close to oil/gas fields. The earthquakes are generally small (Mw < 5) and are shallow with focal depths of about 2 to 8 km. We determined the location and source mechanism of these local earthquakes, with the uncertainties, using a Bayesian inversion method. Our results show that most likely these local earthquakes occurred on pre-existing faults and may have been triggered by oil field activities. In Kuwait, where oil fields are close to populated areas, these induced earthquakes could produce ground accelerations high enough to cause damage to local structures. Chapter 4 is devoted to the study of acoustic emissions during the rock fracturing experiments in the laboratory. The laboratory fracturing can produce pico-seismicity with magnitude as small as -7. Three event-detection and three location algorithms have been implemented to the acoustic emission (AE) data from the fracturing experiment of a cylindrical Berea sandstone sample (Diameter: 36.43 mm; Height: 76.7 mm). The first P-amplitude and waveform-based Bayesian moment tensor inversion algorithms have been applied to the AE data to study the source mechanisms of this fracturing related pico-seismicity. The location, and sensor calibration are discussed in the thesis. The main contribution from this thesis are: 1) Developing a waveform-based Bayesian moment tensor approach; 2) Understanding the source mechanisms of local earthquakes in Kuwait, and simulating the ground motion due to regional and local earthquakes in Kuwait; 3) Characterizing the laboratory-scale fractures using the fracturing related acoustic emission data. / by Chen Gu. / Ph. D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 127-138). / The interiors and surfaces of the terrestrial planetary bodies provide us a unique opportunity to gain insight into planetary evolution, particularly in the early stages subsequent to accretion. Both Mars and the Moon are characterized by well-preserved and ancient surfaces, that preserve a record of geological and geophysical processes that have operated both at the surface and in the interior. With accessibility to orbital and landed spacecraft, the Moon and Mars have a unique qualitative and quantitative role in understanding and constraining the evolution of solid planets in our Solar System, as well as the timing of its many major events. In this thesis I use gravity and topography data to investigate aspects of the surface and interior evolution of the Moon and Mars that include aspects of major processes: impact, volcanism, erosion and internal dynamics. / by Alexander Joseph Evans. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2004. / Includes bibliographical references (p. 142-143). / A model has been developed to analyze the benefit of utilizing a processing plant architecture so that a lunar oxygen production demonstration mission can also provide a significant exploration and scientific return. This architecture will send one lander to the lunar surface with the capability of producing its own propellant to launch itself to multiple sites of scientific interest. It is compared with two other possible planetary exploration architectures: the multiple mission architecture which sends one mission to each landing site of interest, and the fully fueled architecture which sends one mission with enough propellant to launch itself to all selected landing sites. A value of the total mass savings of the processing plant architecture over these two architectures is used as a means of quantifying the benefit for future lunar exploration. The mass of the power system is found, to be the dominant component of the overall system mass for all cases using a Cassini type : RTG. Results from model runs have shown that at Cassini RTG efficiencies this architecture will not be beneficial in highland regions; however, a significant benefit is shown when using mare and glassy type feedstocks. Further data and analysis is needed to confirm the extent of this benefit. At Cassini RTG efficiencies, a processing plant architecture exhibits significant benefit in mare regions when launching once every [approximately] 2 months or longer. Launching every 2 months creates a benefit for a minimum of 12 launches with a launch range of up to [approximately] 10km. Using pyroclastic glasses as the feedstock produces a benefit when launching once every [approximately] 2 months or longer as well. Launching every 2 months creates a benefit for a minimum of 12 launches / (cont.) with a launch range up to [approximately] 13km. Utilizing a longer time between launches significantly increases the launch capabilities. In the near future, RTGs are expected to quadruple in efficiency. With the expected RTG efficiencies the processing plant architecture has an even higher range of benefit for mare and glassy feedstocks. Highland region exploration is only expected to be beneficial with this architecture if further advances in RTG efficiency are made and if system degradation is not severe over a mission timeframe of several years. Advanced RTG technology is identified as the primary technology of need for increasing the benefit of possible processing plant missions. Future versions of this model will be created to better understand and quantify the exact benefit and system dynamics of this architecture. / by Joshua Neubert. / S.M.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1995. / Includes bibliographical references. / by Noriyuki Namiki. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references (page 22). / The Lower Charles River has been a heavily utilized urban river that runs between Cambridge and Boston in Massachusetts. The recreational usage of the river is dependent on adequate water depths and there have been no definitive prior studies on the sedimentation rate of the Lower Charles River. The river transitioned from tidal to a freshwater basin in 1908 and the study area for historical comparisons was from the old Charles River Dam to the Boston University Bridge. This study surveyed the river, digitized three prior surveys that spanned 114 years, calculated volumes and depth distributions for each survey, and estimated sedimentation rates from fits to the volumes over time. The average sedimentation rate is estimated as 5-10 mm/year, which implies 1.8-3.5 feet sedimentation since 1908. Sedimentation rates and distributions are necessary to develop comprehensive management plans for the river. / by Madonna K. Yoder. / S.B.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1990. / Includes bibliographic references (p. 131-133). / by Robert John Conzemius. / M.S.