The south central Chilean margin is one of the most seismically active subduction zones on Earth, generating some of the largest earthquakes on the planet, including the largest ever recorded in 1960 near Valdivia, Chile (Mw 9.5). Using the 15 km streamer and 6600 in3 tuned seismic airgun array aboard...
Signals from the R/V Langseth’s tuned airgun array were recorded on an array of 33 EarthScope FlexArray seismometers deployed in the Oregon Coast Range from 43.5° to 45°N as part of the 2012 Ridge2Trench experiment to image the structure of the Juan de Fuca plate. This segment of the Juan...
Both travel times and amplitudes of large offset refracted and reflected arrivals
observed during GLIMPCE (Great Lakes International Multidisciplinary Program on
Crustal Evolution) along line A in Lake Superior have been modeled using two-dimensional
ray tracing techniques. Forward modeling was used to iteratively refine an
initial velocity model that was...
This thesis presents elastic finite difference simulations of two dimensional wavefield propagation for line-9, recorded during the 1993 part of the multi-institutional, multi-year Mendocino Triple Junction (MTJ) Seismic Experiment. Line-9 is a high-resolution, large-aperture seismic profile oriented in north-south direction, extending from the subduction regime north of the MTJ to...
Since 2003, 39 small earthquakes have been detected offshore central Oregon in the nominally locked part of the Cascadia subduction zone, where very little seis- mic activity has been recorded in spite of a paleo-seismic record of great subduction events. Although the regional earthquake bulletin reports depths of 29 and...
To investigate the dynamic response of the outer accretionary wedge updip from the patch of greatest slip during the Mw8.8 2010 Maule earthquake, 10 Ocean Bottom Seismometers (OBS) were deployed from May 2012 to March 2013 in a small array with an inter-instrument spacing of ~10 km. Nine instruments were...
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Anne M. Tréhu
To investigate the dynamic response of the outer accretionary wedge updip from
The Queen Charlotte Fault system is a segment of the North America - Pacific
plate boundary. From 45 Ma - 5 Ma, plate motion has been primarily translational.
Since 5 Ma, transpression has been the dominant mode of interaction. The plate
boundary west of the Queen Charlotte Islands is characterized...
The Gorda Escarpment (40.4° N and from 126° W to 124.7° W) is a topographic high which is the eastern portion of the Mendocino Transform Fault. The Vizcaino Block is the anomalously shallow portion of the Pacific plate immediately south of the Gorda Escarpment. Sediments of the Vizcaino Block record...
Magnetic and gravity modelling was completed along two E-W transects offshore central Oregon. These models indicate that the backstop-forming western edge of the Siletz terrane has a seaward dip of approximately 40° to 49° at 44°48'N, shallowing to ~28° at 44°1 1 'N. This is a well-determined result, given available...
A 3D seismic volume was acquired summer 2000 over the southern end of Hydrate Ridge (FIR), an anomalously shallow ridge 100 km offshore Newport, Oregon. The survey followed a succession of scientific expeditions aimed at studying the gas hydrates present in the shallow subsurface that gave the name to the...