The southeastern Brazilian continental margin has a debated evolution regarding postrift events and formation of topography. Apatite fission track (AFT) and apatite U-Th/He (AHe) analysis ages for the N-S transect between Rio de Janeiro and Três Rios range between 98.5±11.9 and 54.1±4.2 Ma. Ages are younger towards the coast and increase progressively inland. Highest samples (around 1500 m above sea level) have older AFT ages. A wide range of ages was not found in the area, contrasting with the large AFT age span found by other studies in adjacent portions of the Brazilian continental margin, where age ranges of up to ~200 Ma from the coast to the innermost sample in the continent have been reported. The cooling ages and the thermal history models produced with software QTQt corroborate a uniform and continuous cooling process for the rifted margin, with total depths of denudation between 2.5 and 4.4 km, attesting to the absence of post-Cretaceous rift reburial in the area. Towards the continental interior, at the back of the Serra do Mar escarpment, thermal history models point to a change in cooling rate in the Upper Cretaceous, compatible with reported reactivation of the regional Neoproterozoic structures which led to the formation of the Cenozoic Rift System of Southeastern Brazil. Collision episodes in the western margin of W Gondwana have important role on platewide stress distribution, inducing regional structure reactivation and creation throughout the South American Platform. The plate-wide deformation arising from the western plate margin collisions is possibly responsible for the formation of the many Paleozoic grabens, which were the precursors of the cratonic basins of the South American continent. Among those, evidence from zircon U-Pb detrital provenance indicates that the Ordovician Piranhas Graben in central Brazil is in fact an early manifestation of the Paraná Basin, since its progressive increase in catchment area matches the sediment sources of the Silurian Vila Maria and Devonian Ponta Grossa formations of the Paraná Basin. The present-day landscape is mainly a result of isostatic rebound due to erosional unloading, although combined with post-rift magmatism and regional structure reactivation. The post-rift continuous uplift of the southeastern Brazilian margin supplied vast volumes of clastic sediments to the Santos and Campos basins during the late Cretaceous and Cenozoic, generating high quality reservoirs for hydrocarbons.

Thesis (M.S.)--Ohio University, August, 2009. / Title from PDF t.p. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 168-186). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 168-186). Also available on the Internet.

Thesis (Ph. D.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains vii, 117 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--Missouri University of Science and Technology, 2010. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed June 30, 2010) Includes bibliographical references (p. 129-135).

Recent advances in the use of thermal proxies provide a window into how faults slip during earthquakes. Faults have a similar large-scale structure with a fault core, where earthquakes nucleate, and a surrounding damage zone, but complexities in fault zone architecture and rheology influence earthquake propagation. For example, changes in thickness of slipping layers in the fault core, compositional heterogeneity, and fault surface topography can influence fault strength and either facilitate or arrest a rupture. A further barrier to our understanding of earthquake behavior is in constraining the frictional energy that goes into the earthquake energy budget. Earthquakes can propagate when the energy available at the rupture tip is greater or equal to the energy being expended through radiation of seismic waves, permanent deformation within the process zone, and heat through friction. By quantifying the total energy involved in coseismic slip we can gain a more complete picture of the energy required for rupture propagation and how this may vary across faults. Although fracture and radiated energy can be constrained seismologically, thermal energy requires quantification by other means, and up until recently only few estimates existed for frictional energy. In this thesis I utilize biomarker thermal maturity to quantify temperature rise across multiple faults and explore what this can tell us about earthquake behavior. In chapters two through four, I focus on three large faults of varying structural and rheological complexity. Beginning with the Muddy Mountain thrust of southeast Nevada in Chapter two, I identify thermal evidence of coseismic slip in principal slip zones (PSZs) along this exhumed fault. I show that considerable heterogeneity in the thickness of slipping layers occurs a long a fault and that this has a large effect on coseismic temperature rise and hence fault strength, due to the effect of high temperature dynamic weakening mechanisms. In Chapter three, I move on to the creeping central deforming zone of the San Andreas fault, and show that it has experienced many large earthquakes that are clustered in a 4 m-wide zone adjacent to an actively creeping region. This work shows that the central San Andreas fault and other creeping faults can host seismic slip and should be included in seismic hazard analyses. Furthermore, I demonstrate the potential of K/Ar dating as a tool to constrain the age of earthquakes and find that these central San Andreas fault events are as young as ~3.3 Ma. In Chapter four, I focus on the Hikurangi Subduction zone, which has hosted large earthquakes and regular slow slip events in the past. Here, using drill core collected through the Pāpaku fault, a splay fault of the Hikurangi megathrust, I find evidence of temperature rise in the fault zone and deep hanging wall. Coupled forward models of heat generation and biomarker reaction kinetics estimate that displacement during these earthquakes was likely 11-15 m. These and other splay faults along the margin may pose considerable seismic and tsunami hazard to near-shore communities in the North Island of New Zealand. In Chapter five I explore what we have learned about fault behavior from biomarkers and other thermal proxies. I include measurements from five new faults and compile observations and measurements from past studies to explore how coseismic slip is localized across fault zones and put together a database of frictional energy estimates. Coseismic slip can broadly be described by two different scales of earthquake localization and that this is a function of total displacement, and to a lesser extent, material contrast across the fault. I see that frictional energy is relatively similar across faults of different displacement, depth, and maturity, and conclude that frictional energy is limited by the onset of dynamic weakening. Finally, I put together constraints on the energies involved in the budget to produce the first complete view of the earthquake energy budget and provide estimates of the total energy required for earthquake rupture across different faults.

Indiana University-Purdue University Indianapolis (IUPUI)

Indiana University-Purdue University Indianapolis (IUPUI) / Over the past two decades, northern parts of the United States have experienced extreme heat conditions. Some of the notable heat wave impacts have occurred in Chicago in 1995 with over 600 reported deaths and in Philadelphia in 1993 with over 180 reported deaths. The distribution of extreme heat events in Indianapolis has varied since the year 2000. The Urban Heat Island effect has caused the temperatures to rise unusually high during the summer months. Although the number of reported deaths in Indianapolis is smaller when compared to Chicago and Philadelphia, the heat wave in the year 2010 affected primarily the vulnerable population comprised of the elderly and the lower socio-economic groups. Studying the spatial distribution of high temperatures in the vulnerable areas helps determine not only the extent of the heat affected areas, but also to devise strategies and methods to plan, mitigate, and tackle extreme heat. In addition, examining spatial patterns of vulnerability can aid in development of a heat warning system to alert the populations at risk during extreme heat events. This study focuses on the qualitative and quantitative methods used to measure extreme heat events. Land surface temperatures obtained from the Landsat TM images provide useful means by which the spatial distribution of temperatures can be studied in relation to the temporal changes and socioeconomic vulnerability. The percentile method used, helps to determine the vulnerable areas and their extents. The maximum temperatures measured using LST conversion of the original digital number values of the Landsat TM images is reliable in terms of identifying the heat-affected regions.