In this thesis anomalous downcore shallowing of paleomagnetic
inclinations is interpreted to be caused by sediment compaction. Thus,
compaction-induced inclination shallowing may influence tectonic
reconstructions that are based on inclinations from deep-sea sediment
cores.
Progressive downcore shallowing of the remanent inclination was
observed in a 120-m section of Plio- Pleistocene...
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...
In April of 1974, Oregon State University conducted a geophysical
survey of the Orozco fracture zone, a Left-lateral transform fault
which offsets the East Pacific Rise off the coast of Mexico near
15°N, 105°W. Magnetic, gravity, bathymetric, and seismic reflection
data were collected during a four day period. This survey...
A free-air gravity anomaly map of the continental margin of
Peru between 12° and 18° S. Lat. shows a -110 to -220 mgl anomaly
associated with the Peru-Chile Trench, a -60 mgl anomaly over the
Pisco Basin on the continental shelf, and -120 mgl anomaly over the
Mollendo (or Arequipa)...
An airgun refraction line along the length of the caldera of Axial Seamount as
recorded by three Ocean Bottom Seismometers has been analyzed using the tau-zeta
inversion technique (Dorman and Jacobson, 1981). Five resulting velocity profiles
show that the seismic velocities of the upper 1.4 km of the crust are...
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...
The seismicity at the northern section of the Gorda Ridge has been
studied with Ocean Bottom Seismographs. Nearly one hundred earthquakes
were located with RMS travel time residuals less than 0.5 seconds.
Most of these events lie within or near the array and they are probably
associated with the dynamics...
We have determined the seismic crustal structure of the
northern part of the Gorda Ridge using signals generated by
explosive charges and recorded on Ocean Bottom Seismometers. The
shot pattern forms two parallel lines, one on the east flank and the
other along the median valley. Inversion of the travel...