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....
Geophysical data collected in 1975 and 1976 reveal major
crustal and tectonic elements of the continental margin of southern
Baja California. Gravity, magnetic, seismic reflection and bathymetric data show seaward extension of the islands enclosing Magdalena
and Almejas Bays. A seismic reflection profile, oriented
approximately normal to the trend of...
Seismic properties (P, S velocities and Poisson's ratio) of
young (0.75 m.y.) and mature (110 m.y.) oceanic crust are obtained
by studying explosive refraction data collected in the Pacific Ocean
using ocean bottom and downhole seismometers. A comparison of the
results for the two regions indicates that the upper crustal...
The Gorda Basin is a young oceanic plate which comes in direct
contact with the convergent margin of western North America. Two long
sonobuoy refraction profiles crossing the basin provide nearly continuous
data for computing the velocity structure of the crust and adjacent
continental slope. Time-term analysis utilizing multiple receivers...
Seismic refraction measurements along two unreversed lines
indicate that the earth's crust is 26 km thick in southeastern Alaska
and 30 km thick along the Inside Passage of British Columbia. The
crust in southeastern Alaska, north of Dixon Entrance, consists of
a layer 9 km thick with a seismic velocity...
At collisional mountain ranges the tectonic history of crustal shortening and
subsequent post-collisional erosion is preserved in the form of the presently observed
gravity anomalies. In this study, models of erosion and isostatic rebound at various stages
of collision illustrate the evolution of crustal structure, topography, and resulting gravity
anomalies....
Surface and subsurface data from the Sulaiman thrust belt show that nearly all
the 10 km thick sequence of dominantly platform (>7 km) and molasse strata is detached
at the deformation front. These strata thicken tectonically to a minimum of 20 km in the
hinterland of the Sulaiman fold belt...