Super-Resolution is the process of obtaining a spatial resolution greater than that of the original resolution of a data source. This can be done through the fusion of original data with an additional source that has the desired resolution. These approaches can either be qualitative for visual appeal, quantitative for data accuracy, or some combination of both. The super-resolution approach offers an alternative to traditional sub-pixel deconvolution identification and provides higher resolution TIR data for Earth and Mars. The Thermal Emission Imaging System (THEMIS) has provided the highest spatial resolution (100 meter / pixel) thermal infrared (TIR) data of the Mars surface to date. These data have enabled the discovery of small-scale compositional units and helped to constrain surface processes operating at these scales. Higher resolution visible instruments have revealed smaller-scale differences, creating a need to detect compositional variability using TIR data at scales below 100 meters. Putative chloride deposits identified on Mars are one such area. These deposits have a unique spectral signature in the TIR and are present within topographic lows. The super-resolution algorithm helped constrain the local mineral assemblages and stratigraphic order. This data reveals that associated phyllosilicate-rich units may be part of a common lithostratigraphic unit with a phyllosilicate-poor ST-2 material. Lunar Lake playa, located ~100 km northeast of Tonopah, Nevada, has been used as an analog site for multiple planetary surfaces and as a vicarious calibration site for Earth-orbiting satellites. As such, the ability to obtain higher resolution data through super-resolution has the potential to improve Earth data and give to insight into the formation of similar environments on other planetary surfaces. Super resolved data show Lunar Lake playa to be more compositionally heterogeneous than previously thought. A gradation of mineralogy exists within the playa, seen in both super-resolved data and in samples collected during fieldwork. The composition of the playa is influenced by the immediate surroundings, with variation existing between the western side of the playa, bounded by basaltic units, and the eastern, bounded by rhyolitic tuff. As the surrounding material weather, different clasts are transported onto the playa, and weather into different mineral assemblies.

The delivery of precipitation to southwestern China is largely through monsoon circulation which has evolved with changing insolation forcing during the Holocene and will likely continue to change in response to greenhouse gas increases. Additionally, southwestern China has a long history of human activity including mining, metallurgy, agriculture, and pollution. Here, high-resolution sampling of a sediment core from Lake Xing Yun in the Yunnan Province (24°10N, 102°46E), a drought sensitive lake that behaves as a closed basin, provides a sub-decadal record of changing climate and human activity in the late Holocene. We use δ18O and δ13C measurements of authigenic carbonate precipitated from the lake water and magnetic susceptibility values to document the timing, direction, and magnitude of moisture changes associated with variations in monsoon strength. We use δ13C and δ15N measurements on organic matter and carbon to nitrogen ratios to assess the impact of human activity on the Xing Yun watershed and sediment trace metal concentrations in investigate regional mining and smelting intensity. The 2,500 year record highlights several transition periods related to both human and climate forcing. The rise of metallurgy and intensive mining practices occurs at 900 AD, much later than historical records indicate. A number of proxies including δ13C values and C/N ratio show a marked shift at 1600 AD, the time in which many Han immigrants from the north settled and worked the land in the Yunnan Province. The most pronounced feature of the record is a rapid transition to a substantially drier climate that took place over 50 years and persisted from 1360-1880 AD as an expression of the Little Ice Age (LIA). This project demonstrates that complex human and climate interactions have been taking place for thousands of years and have the potential to illuminate discontinuities in Chinese historical records and learn lessons that might apply to future climate change.

Thermal infrared (TIR) remote sensing is a useful tool for the detection and analysis of volcanic surfaces. The data have been used to determine heat flux, eruption rates, surface petrology, geochemistry, and textures, for example. The majority of past studies using TIR spectroscopy for compositional determination have focused primarily on crystalline minerals, as minerals possess high-order molecular structure, and unique and identifiable TIR spectral features. Although ubiquitous in both hazardous and non-hazardous volcanic terranes, silicate glasses are poorly studied spectrally. This is primarily due to the amorphous and structurally-disordered nature of glasses, which causes them to display very similar spectral features regardless of composition. Because of this, glasses are difficult to distinguish spectrally in the TIR, especially at lower spectral resolutions. Furthermore, spectral features change with the changing physical state of the glass. For example, as a silicate glass transitions from a solid to a molten state, the glass structure becomes less polymerized, bond angles within the O-Si-O structure decrease, and the number of non-bridging oxygens (NBO) increase. These structural changes are reflected in thermal emission spectra as a broadening of the main Si-O spectral feature, and an increase in its wavelength position. A micro glass-melting furnace has been developed specifically for use with a Nexus 670 FTIR spectrometer in order to collect in-situ thermal emission spectra of actively melting and cooling synthetic silicate glasses of dacitic and rhyolitic composition. Changes in the wavelength position, the emissivity, and the width of the laboratory emission spectra have been observed as the glasses transition from a fully molten to a completely solid state. Differences in spectral behavior and morphology are observed between a glass in a solid state, and its molten counterpart. Furthermore, the approximate temperature range over which the glass transition takes place is also identified. This growing library of laboratory-acquired solid glass and melt spectra will be used in conjunction with TIR airborne and field-based remote sensing instrumentation to more definitively characterize the ever-changing composition and physical state of active silicic lava domes and flows. This, in turn, will contribute to improvement of mapping and hazard assessment of volcanic environments.

Water resources in the American west are under mounting stress due to increasing demand, receding glaciers, and diminishing winter snowpack amounts. By understanding past aridity patterns, we can improve the ability of global climate models to predict regional hydroclimatic conditions in the coming decades and centuries. Such forecasting is critical to the development of sound water allocation policies. To produce accurate forecasts, global climate models rely on paleo-proxy evidence to constrain climate parameters that govern, for example, important potential changes in the El Niño Southern Oscillation and its associated impacts on extratropical precipitation and drought patterns in response to future anthropogenic climate forcing. Lake sediment oxygen isotope records are one such form of paleo-proxy evidence, providing valuable information about past climatic conditions on time scales ranging from years to millennia. Here a numerical lake-catchment model defined by a system of twelve ordinary differential equations is developed and used to describe the physical processes controlling lake-catchment hydrology and oxygen isotope dynamics. This model is applied to Castor Lake and Scanlon Lake, central Washington, and used to conduct simulations designed to characterize lake hydrologic and isotopic responses to mean state and stochastic hydroclimatic variability. Ultimately, the Castor Lake sediment oxygen isotope record is interpreted using an ensemble of Monte Carlo lake model simulations to produce a probabilistic, quantitative reconstruction of precipitation amounts over the past 1500 years. This reconstruction indicates that the Medieval Climate Anomaly (MCA) (9501250 BP) was a relatively wet period and that the Little Ice Age (LIA) (14501850 BP) was relatively dry, suggesting that the MCA was characterized by a La Niña like state of the tropical Pacific and the LIA was characterized by El Niño like conditions. These results are the first quantitative, probabilistic estimate of paleo-precipitation using lake sediment oxygen isotope records from the interior Pacific Northwest, and will provide a resource for the parameterization of climate models designed to investigate future Pacific Ocean responses to anthropogenic forcing and the associated influence on aridity patterns in the American west.

The Salton Sea Geothermal Field is an active 20 km2 region in southern California, which lies along the Calipatria Fault; an offshoot of the San Andreas Fault. Several geothermal fields (including the Davis-Schrimpf and Sandbar fields) and ten power plants generating 340 MW lie within this region. To better understand the mineral and thermal distribution of the surface, hyperspectral thermal infrared (TIR) data were acquired by The Aerospace Corporation using the Spatially Enhanced Broadchannel Array Spectrograph System (SEBASS) airborne sensor on March 26, 2009 and April 6, 2010. SEBASS collects 128 wavelength channels at 1 meter spatial resolution. Such high resolution data are rarely available for this type of scientific analysis and enabled the identification of mineral assemblages associated with geothermally-active areas. This study was supported by field based thermal readings and surface samples. Thermal readings obtained remotely and in the field are also used to better understand the dynamics of the piping and heat flux this system. High resolution remote sensing of this area enables the identification of minerals associated with geothermally active areas and the subsequent use as indicator minerals to discover other, previously unknown, active areas. These minerals include anhydrite and one unknown mineral. Scanning electron microscopy (SEM) and x-ray diffraction (XRD) were performed on one of the samples in order to positively identify this mineral and further constrain the TIR analysis. Data obtained by the SEBASS sensor were later regressed to the 32 channel spectral resolution of the future Mineral and Gas Identifier (MAGI) sensor. At this lower spectral resolution these important geothermal indicator minerals are still effectively identified. Therefore, proving the satellite imager counter-part of this sensor, MAGI-L, would be a much desired follow-on instrument to the 5 TIR channel resolution Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) sensor, by producing accurate identification of surface mineralogy previously not detected by an orbiting sensor. Work performed during this research has the potential to be used at other geothermal sites to better characterize transient mineralogy, understand the influence of surface and ground water in these systems, and ultimately to identify new geothermal targets for future exploration.

The Specter Range thrust (SRT), which extends from Mercury to Amargosa, Nevada, emplaces Precambrian silicic rocks of the Wood Canyon Formation onto middle Paleozoic folded rocks which constitute the regional carbonate aquifer. Field evidence suggests that the regional carbonate aquifer and underlying aquitard in the Specter Range have been thinned by nearly 35%, or 3,000 m along detachment horizons parallel or sub-parallel to bedding. Several regional detachments that generally coincide with sections of shaly or sandy beds also commonly affect hundreds of meters of adjacent beds as shown by breccia composed of granules to small boulders, as well as local large boulders and mega blocks, especially in dolomite units. Quartzose clastic confining units generally are strongly brecciated and may be unexpectedly porous and permeable. The stratigraphically highest breccia mass is preserved only in the southern Specter Range, where it comprises tens to hundreds of meters of breccias derived mainly of Silurian and Devonian dolomite beds. In these units, brecciated throughout, the formation of breccia is highly variable with the smallest grain size commonly developed along steep, narrow zones within coarser, massive breccia composed of mega-blocks and bedded sections cut and disrupted by numerous fractures and faults generally marked by breccias. The detachments and related contractional structures locally affect Tertiary strata that constrain the timing of deformation between about 15 and 10 Ma. As previously recognized, transpression at a left-step along the right-lateral Las Vegas Valley Shear Zone (LVVSZ), between Mercury and Amargosa, Nevada is likely responsible for the contraction. Stratigraphic studies have shown that the LVVSZ accommodates several tens of km of movement. The brecciated carbonate aquifer and clastic aquitard may provide fast pathways for groundwater moving from the NTS southward. Monitor wells in the vicinity of Rock Valley fault, north of the Specter Range, could provide information about southward-moving-groundwater before reaching the faulted and brecciated rocks of the Specter Range.

Very few studies exist on the processes and products of formerly ice-confined, multiple vent and multiple fissure basaltic ridge complexes, even though it is estimated that more than 1000 of these structures exist in Iceland. This is the first study that examines the processes, products and depositional environments of such complexes over space and time. The 21-km long, 2.5 km wide and 250 m thick Sveifluháls ridge in SW Iceland was used as a case study to better understand the nature of these complexes. Ridge growth began with eruptions beneath a 450-600 m thick ice sheet sometime between 43,000-12,400 years BP. The resulting melting ice and dropping overburden pressures facilitated the eruption of vitric phreatomagmatic tuff into one or more ice-confined meltwater lakes. These eruptions formed tuff cones, elongate tuff cones and narrow (0.5 km) tuff ridges, and collectively these formed a series of regularly-spaced (average spacing of 0.7 km) edifices along ~60 semi-parallel individual linear segments that vary in length from 0.25 km to 1.5 km. Tuff ridges represent edifices formed from Surtseyan fissure eruptions, and are described for the first time. All of the edifices grew by deposition from subaqueous density currents and/or by suspension and settling of phreatomagmatic tuff within the meltwater lakes. Tuff was commonly remobilized by slope failure due to melting and retreat of supporting ice walls, over steepening of the subaqueous tephra pile, and/or by disturbance from intrusions that propagated into wet tuff. The majority of tuff units at Sveifluháls are not in-situ, and about half of these contain chaotically-dipping beds that are suggestive of slumping and movement before final emplacement. Tuff cones and ridges grew to enclose inter-ridge catchments with volumes as large as 1.5x107 m3. These impoundments are interpreted as important sources for jökulhlaups. The total DRE volume of the ridge was ~2.0 km3 and an estimated total of 17.25 km3 of meltwater may have been generated during the eruptions of Sveifluháls. Prior to cessation of the eruptions, the ice-confined meltwater lake drained to 200 m below the original edifice height, and subaerial lava was erupted from at least one eruption center.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Earth and Planetary Science, 1972 / Vita. / Bibliography: p. 186-188 / Ph. D. / Ph. D. Massachusetts Institute of Technology, Department of Earth and Planetary Science

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Earth and Planetary Science, 1972 / Vita. / Bibliography: leaves 237-253. / by Donald James Weidner. / Ph. D. / Ph. D. Massachusetts Institute of Technology, Department of Earth and Planetary Science

Thesis: M.S., Massachusetts Institute of Technology, Department of Earth and Planetary Science, 1972 / Bibliography: leaves 89-93. / M.S. / M.S. Massachusetts Institute of Technology, Department of Earth and Planetary Science