Publications
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Preliminary report on some factors affecting shotpoint efficiency
A study of first-arrival amplitudes from 6 water shotpoints and 7 drill-hole shotpoints in parts of central and western United States indicate a variation of over 100 to 1 between the best and poorest shotpoints. Water shotpoints are, in general, superior to drill-hole shotpoints; however, one drill-hole shotpoint produced higher signal amplitudes than more than half of the water shotpoints. Signa
Authors
W. H. Jackson, J. H. Healy
Preliminary report on the geologic and geophysical investigations of the Loveland Basin landslide, Clear Creek County, Colorado
No abstract available.
Authors
Charles Sherwood Robinson, Fitzhugh T. Lee, R. D. Carroll
Geomagnetic polarity epochs
[No abstract available]
Authors
A. Cox, Richard R. Doell, G. Brent Dalrymple
Preliminary study of first motion from nuclear explosions recorded on seismograms in the first zone
The U.S. Geological Survey has recorded more than 300 seismograms from more than 50 underground nuclear explosions. Most were recorded at distances of less than 1,000 km. These seismograms have been studied to obtain travel times and amplitudes which have been presented in reports on crustal structure and in a new series of nuclear shot reports. This report describes preliminary studies of first m
Authors
J. H. Healy, G. B. Mangan
Crustal structure in the vicinity of Las Vegas, Nevada, from seismic and gravity observations
A seismic-refraction profile indicates that the crust of the Earth increases in thickness by as much as 5 km over a horizontal distance of less than 25 km northeast of Las Vegas, Nevada. This feature correlates with a decrease in the Bouguer anomaly and an increase in the average surface altitude.
Authors
John C. Roller
Crustal structure from San Francisco, California, to Eureka, Nevada, from seismic-refraction measurements
Seismic-refraction measurements from chemical explosions near San Francisco, California, and Fallon and Eureka, Nevada, were made along a line extending nearly 700 km inland from San Francisco across the Coast Ranges, Great Valley, Sierra Nevada, and Basin and Range Province. The velocity of Pg in the Basin and Range Province was found to be 6.0 km/sec. Between Fallon and Eureka the velocity of Pn
Authors
Jerry P. Eaton
Traveltimes and amplitudes from nuclear explosions; Nevada Test Site to Ordway, Colorado
This paper treats the results of a study of seismic waves generated by eight nuclear explosions and recorded at 31 locations between the Nevada Test Site (NTS) and Ordway, Colorado. The line of recording stations crosses the eastern part of the Basin and Range Province, the Colorado Plateau, the southern Rocky Mountains, and extends into the Great Plains. In the eastern Basin and Range Province an
Authors
Alan Ryall, David J. Stuart
Crustal structure in the western United States; study of seismic propagation paths and regional traveltimes in the California-Nevada region
The U.S. Geological Survey, with the assistance of United ElectroDynamics, Inc., completed ten weeks of seismic-refraction field work during the summer of 1962 in the southwestern part of the United States. This work was a continuation of a program initiated in 1961 to study traveltimes and seismic propagation paths in the earth?s crust and upper mantle in the western United States. A total of 761
Authors
J.C. Roller, W. H. Jackson, J.F. Cooper, B.A. Martina
Structure of the crust and upper mantle in the western United States
Seismic waves generated by underground nuclear and chemical explosions have been recorded in a network of nearly 2,000 stations in the western conterminous United States as a part of the VELA UNIFORM program. The network extends from eastern Colorado to the California coastline and from central Idaho to the border of the United States and Mexico. The speed of compressional waves in the upper-mantl
Authors
L. C. Pakiser
Preliminary report on seismic-reflection studies of crustal structure in the western, central, and southern United States
During 1963 the U.S. Geological Survey, with the assistance of United ElectroDynamics, Inc., recorded five separate reversed seismic profiles. In addition to these profiles, the U.S. Geological Survey participated in a seismic-calibration program for the DRIBBLE experiment at Tatum Dome, Mississippi, a 20,000-pound shot near Dexter, Missouri, and in a cooperative seismic experiment in the Lake Sup
Authors
J.C. Roller, O.P. Strozier, W. H. Jackson, J. H. Healy
A progress report on seismic model studies
The value of seismic-model studies as an aid to understanding wave propagation in the Earth's crust was recognized by early investigators (Tatel and Tuve, 1955). Preliminary model results were very promising, but progress in model seismology has been restricted by two problems: (1) difficulties in the development of models with continuously variable velocity-depth functions, and (2) difficulties i
Authors
J. H. Healy, G. B. Mangan
Preliminary report on landslides in a part of the Orinda Formation, Contra Costa County, California
No abstract available.
Authors
Dorothy Hill Radbruch, Louise M. Weiler