A proposed modeling technique that yields a best fit to observed wide-angle reflection profiles incorporates (1) the use of migrated vertical reflection profiles to provide topographic control, (2) ray tracing to produce theoretical wide-angle reflection profiles for hypothetical crustal sections, and (3) the iterative adjustment of crustal layer dip, thickness...
Seismic refraction, reflection and gravity data obtained
across the Peru continental margin and Nazca Plate
at 9° S. permit a detailed determination of crustal structure.
Complex structures normal to the profile require the
development of a ray trace technique to analyze first and
later arrivals for eleven overlapping refraction lines....
A marine seismic refraction study, conducted in August 1976 by personnel
from Oregon State University and the University of Connecticut between Cape
Simpson and Prudhoe Bay, Alaska, provides data for analysis which yields a
subsurface structural and geological cross-section of the area.
The results suggest that the structural homocline which...
Recently obtained airgun-sonobuoy wide-angle refraction and
reflection profiles provide data to study crustal velocities and
structures along the continental margin of northern California and
Southern Oregon.
In the thick sedimentary wedge at the base of the continental
slope, as many as five distinct layers can be seismically observed,
which range...
University deployed two arrays of three sonobuoys over the Blanco
fracture zone and two arrays of four sonobuoys over the Gorda ridge
to detect and locate microearthquakes. Microearthquake activity predicted
by plate tectonic theory for the Blanco fracture zone and Gorda
ridge was observed by these arrays to originate from...
Three seismic refraction profiles obtained between 42°N and
43°N along the median valley of the Gorda Ridge, an active spreading
center, allow the computation of the velocity structure underlying the
valley. Wide angle reflections which appear on the seismic records
suggest the existence of a velocity inversion underlying layer 3...
Deterministic source signature deconvolution is applied to the
processing of marine wide angle and vertical profiler data with air-gun
sources. Optimum results are obtained with a source signature
measured by stacking the signal reflected from a relatively homogeneous
abyssal plain sedimentary environment. This eliminates the need for
the unstable inverse...
The 1979 incident at Three Mile Island drew attention to weaknesses in the capability to obtain and analyze reactor coolant
samples in an environment where the reactor core incurs significant
damage. As a result, the U.S. Nuclear Regulatory Commission promulgated regulations requiring that reactor coolant analytical capabilities be upgraded so...