The seismic response of deep deposits of liquefiable and cyclic-softening susceptible soils has presented the geotechnical profession with significant engineering challenges. Strong ground motions may serve to soften soils under cyclic shear, trigger liquefaction, and produce damaging displacements as a consequence. This study improves the understanding of the in-situ, nonlinear,...
High‐resolution three‐dimensional (3‐D) seismic reflection data acquired on the R/V Thomas G. Thompson in 2000 reveal a pair of bottom simulating reflections (BSRs) across a broad region of southern Hydrate Ridge, offshore Oregon. The primary BSR (BSRp) is a regionally extensive reflection that lies 120–150 m below seafloor and exhibits...
Diking and channelizing in the Toppenish Creek basin, associated with irrigated agricultural development, has altered its natural ecosystem function and hydraulic processes. We seek to answer two research questions: if surface waters are diverted for aquifer recharge in the winter, will this water be available for ecosystem function in the...
Methane hydrates and biohydrogen are two disparate subjects that are of interest in the growing field of alternative energy research. However, before commercial use becomes a viable option, each has challenges that need to be overcome. Methane hydrates require large investments of time and capital to locate. In this thesis,...
Several approaches to interpreting the Cascadia paleoseismic record are
used to derive relationships between fault area, slip, and moment and to compare the
results with the scaling relationships determined by Somerville et al. (2015) for recent
subduction-zone events. In two models (CA12a and CA12b), taken from Goldfinger
et al. (2012),...
Full Text:
Paleoseismic Record
by Anne M. Tréhu
This electronic supplement contains figures and a table summarizing the
Several approaches to interpreting the Cascadia paleoseismic record are
used to derive relationships between fault area, slip, and moment and to compare the
results with the scaling relationships determined by Somerville et al. (2015) for recent
subduction-zone events. In two models (CA12a and CA12b), taken from Goldfinger
et al. (2012),...
Full Text:
Cascadia Paleoseismic Record
by Anne M. Tréhu
Abstract Several approaches to interpreting the Cascadia
While bubble plumes have been acoustically imaged in the water column above marine gas
hydrate deposits in many studies, little is known about the temporal variation in plume intensity. In
July 2008, we conducted surveys using 3.5 and 12 kHz echosounders and a 75 kHz acoustic Doppler
current profiler (ADCP)...
While bubble plumes have been acoustically imaged in the water column above marine gas
hydrate deposits in many studies, little is known about the temporal variation in plume intensity. In
July 2008, we conducted surveys using 3.5 and 12 kHz echosounders and a 75 kHz acoustic Doppler
current profiler (ADCP)...
The Queen Charlotte Fault is a transpressive transform plate boundary between the Pacific and North American plates offshore western Canada. Previous models for the accommodation of transpression include internal deformation of both plates adjacent to the plate boundary or oblique subduction of the oceanic plate; the latter has been the...
Three-dimensional gravity analysis is the process of removing the predictable
components from the free-air gravity anomalies and has proven to be useful for
interpreting the subsurface structures and active processes at mid-ocean ridges. The
three-dimensional effects of the seafloor and Moho topography, assuming a constant
crustal thickness and constant crust...