In eastern Washington and western Oregon, southwest-northeast striking thrust faults and folds of the Yakima Fold and Thrust Belt (YFTB) and northwest-striking dextral strike-slip faults accommodate north-south contraction resulting from clockwise rotation of the North American Plate. Though present to the east and west of the Cascade Range, the connectivity...
Floodplain forests play many important roles in the fluvial processes and environments of large alluvial rivers, including acting as geomorphological influences and habitat for native fish during high flows. Many large, gravel-bed river systems have undergone substantial change in recent centuries, resulting in loss of forested area to agriculture, reduction...
The word orogenesis is derived from the Greek words oros meaning mountains and genesis meaning creation and refers to the study of the complex processes involved in the growth and evolution of mountain ranges (orogens). Orogens develop where crustal deformation builds topography and forms landscapes. This dissertation explores the role...
Hydrogeologic systems in the southern Cascade Range develop in volcanic rocks where volcanic morphology, stratigraphy, extensional structures and attendant basin geometry play a central role in groundwater-flow paths, groundwater/surface-water interactions, and spring discharge locations. High-volume springs (> 3 m3/s) flow from young (< 1 Ma) volcanic rocks in the Hat...
Discrete fault systems accommodate both N-S contraction and dextral shear in concert with clockwise rotational deformation of the North American plate above the Cascadia Subduction Zone. In Washington, the Yakima Fold and Thrust Belt (YFTB) accommodates N-S contraction as a series of ENE-WSW trending thrust faults and folds. NW-striking, predominantly...
Earthquake rupture scenarios are important tools for understanding the nature of plate movement and patterns in seismic activity. The creation and assessment of these rupture scenarios rely heavily on geologic reasoning and principles applied to earthquake event data. This reliance introduces a certain amount of subjectivity to the rupture scenario...
Active tectonics of a deformation front constrains the kinematic evolution and structural interaction between the fold-thrust belt and the most-recently accreted foreland basin. At the Himalayan deformation front, the thrust front is blind, characterized by a broad fold (the Suruin-Mastgarh anticline (SMA)), and displays no emergent faults cutting the southern...
The state of the knowledge for fault behavior in the northwest Himalaya and California varies dramatically. In the Pakistan and Kashmir Himalaya, few data constrain the role that individual active faults play in accommodating Indo-Eurasian convergence and the relative earthquake hazard across the region. By contrast, the San Andreas fault...
Passive hydrophone technologies and a variety of acoustic methods are applied in
the deep-ocean and shallow water coastal environments of the northeast Pacific. A
catalog derived from U.S. Navy regional hydrophone array recordings of acoustic T- phases from seafloor earthquakes is examined, describing space/time patterns through
empirical orthogonal function analysis...
The Mount Polley copper-gold deposit is one of a series of porphyry copper deposits that occur in a belt of accreted Mesozoic age island arc terranes in the Canadian Cordillera. The deposit comprises three breccia-hosted Cu-Au ore zones that are associated with a series of monzodiorite to monzonite intrusions emplaced...