Global ETD Search

11	Long-term exhumation of landscapes along the Pacific-North American plate boundary as inferred from apatite (U-Th)/He and ArcGIS analyses Buscher, Jamie Todd 31 May 2007 (has links) The Pacific-North American plate boundary is typified by transpression and convergence, yet the relationship between interplate deformation and long-term crustal shortening is not fully understood. The continuous belt of rugged topography that extends along the entire plate boundary is generally associated with oblique tectonic plate motion, strong interplate coupling, and terrane accretion, but relating plate boundary orogenesis to variations in plate geometry and behavior requires detailed case studies. The northern San Gabriel Mountains along the San Andreas fault and the Chugach-Kenai Mountains above the Aleutian subduction zone are located along highly tectonically active sections of the Pacific-North American plate boundary and have not been studied from the context of long-term landscape development. To determine whether mountain building along these sections of the plate boundary reflects recent, rapid exhumation as observed in bordering mountain belts, low-temperature thermochronometry and topographic analyses were applied to each area. In the northern San Gabriel Mountains, apatite (U-Th)/He ages are >10 Ma along narrow crystalline ridges topped by low-slope erosional surfaces located within ~5 km of the San Andreas fault zone. In the Chugach-Kenai Mountains, the youngest apatite (U-Th)/He ages (~5 Ma) are an order of magnitude older than those from the Yakutat collision zone to the east, despite the presence of a continuous swath of glaciated, rugged topography between the two areas. Exhumation rates inferred from these ages are <1 mm/yr, suggesting that there has been minimal recent denudation in the northern San Gabriel and Chugach-Kenai Mountains. The lack of evidence for recent mountain building in both of these case studies implies that interplate deformation is heterogeneous and that other factors (secondary structures, climate) besides plate kinematics and topographic character must be considered for understanding landscape development. / Ph. D. ArcGIS southern San Andreas fault (U-Th)/He dating Aleutian subduction zone exhumation
12	Short-Term Slow Slip Events at Alaska Subduction Zone and their Correlation with Local Tremors Weerasinghe, Dhamsith Asiri 23 August 2022 (has links) No description available. Geophysics Geology Short Term Slow Slip Events SSE GPS Alaska Aleutian Subduction Zone Upper Cook Inlet Tremors
13	A History of Place: Using Phytolith Analysis to Discern Holocene Vegetation Change on Sanak Island, Western Gulf of Alaska Wilbur, Cricket C. January 2013 (has links) No description available. Archaeology Botany Climate Change Conservation Earth Ecology Environmental Science Freshwater Ecology Geology Limnology Native Americans Natural Resource Management Paleobotany Paleoclimate Science Paleoecology Plant Biology Pollen Paleolimnology Phytoliths Phytolith Analysis Aleutian Islands Sanak Island Western Gulf of Alaska Stomata Maritime tundra Grasses Dicotyldons Arctic ecosystems Climate change Paleoenvironmental reconstruction Holocene Lake sediment

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