Natural Hazards

Publications

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Year Published: 1964

Continental crust

The structure of the Earth’s crust (the outer shell of the earth above the M-discontinuity) has been intensively studied in many places by use of geophysical methods. The velocity of seismic compressional waves in the crust and in the upper mantle varies from place to place in the conterminous United States. The average crust is thick in the...

Pakiser, L.C.
Continental crust; 1964; USGS Unnumbered Series; 20; Pakiser, L. C.

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Year Published: 1964

Crustal structure in the eastern Colorado Plateaus Provence from seismic-refraction measurements

A reversed seismic-refraction profile was recorded in the Colorado Plateaus Province from Hanksville, Utah, to Chinle, Arizona, The velocity of Pg is 6.2 km/sec, and the true velocity of Pn is 7.8 km/sec, Waves identified as reflections indicate that an intermediate layer in the crust has a velocity of approximately 6.8 km/sec. Thickness of the...

Roller, John C.
Crustal structure in the eastern Colorado Plateaus Provence from seismic-refraction measurements; 1964; USGS Unnumbered Series; 19; Roller, John C.

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Year Published: 1964

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...

Jackson, W.H.; Healy, J.H.
Preliminary report on some factors affecting shotpoint efficiency; 1964; USGS Unnumbered Series; 17; Jackson W.H.; Healy, J.H.

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Year Published: 1964

Preliminary report on the geologic and geophysical investigations of the Loveland Basin landslide, Clear Creek County, Colorado

Robinson, Charles Sherwood; Lee, Fitzhugh T.; Carroll, R.D.
Preliminary report on the geologic and geophysical investigations of the Loveland Basin landslide, Clear Creek County, Colorado; 1964; OFR; 64-135; Robinson, Charles Sherwood; Lee, Fitzhugh T.; Carroll, R. D.

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Year Published: 1964

Seismic-refraction measurements of crustal structure between Nevada Test Site and Ludlow, California

Seismic-refraction measurements from nuclear and chemical explosions were made along a line from the Nevada Test Site (NTS) to Ludlow, California, and additional recordings from nuclear explosions were made southward toward Calexico, California. The time of first arrivals from the Ludlow shotpoint is expressed as T0 = 0.00 + Δ/2.50 (assumed), T1...

Gibbs, J.F.; Roller, J.C.
Seismic-refraction measurements of crustal structure between Nevada Test Site and Ludlow, California; 1964; USGS Unnumbered Series; 26; Gibbs, J.F.; Roller, J.C.

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Year Published: 1964

Geomagnetic polarity epochs

[No abstract available]

Cox, A.; Doell, Richard R.; Dalrymple, G. Brent
Geomagnetic polarity epochs; 1964; Article; Journal; Science; Cox, A.; Doell, R. R.; Brent, Dalrymple, G.

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Year Published: 1963

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....

Healy, J.H.; Mangan, G.B.
Preliminary study of first motion from nuclear explosions recorded on seismograms in the first zone; 1963; USGS Unnumbered Series; 13; Healy, J. H.; Mangan, G. B.

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Year Published: 1963

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.

Roller, John C.
Crustal structure in the vicinity of Las Vegas, Nevada, from seismic and gravity observations; 1963; USGS Unnumbered Series; 12; Roller, John C.

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Year Published: 1963

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...

Eaton, Jerry P.
Crustal structure from San Francisco, California, to Eureka, Nevada, from seismic-refraction measurements; 1963; USGS Unnumbered Series; 11; Eaton, Jerry P.

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Year Published: 1963

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...

Ryall, Alan; Stuart, David J.
Traveltimes and amplitudes from nuclear explosions; Nevada Test Site to Ordway, Colorado; 1963; USGS Unnumbered Series; 10; Ryall, Alan ; Stuart, David J.

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Year Published: 1963

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...

Roller, J.C.; Jackson, W.H.; Cooper, J.F.; Martina, B.A.
Crustal structure in the western United States; study of seismic propagation paths and regional traveltimes in the California-Nevada region; 1963; USGS Unnumbered Series; 9; Roller, J. C.; Jackson, W. H.; Cooper, J. F.; Martina, B. A.

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Year Published: 1963

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....

Pakiser, L.C.
Structure of the crust and upper mantle in the western United States; 1963; USGS Unnumbered Series; 8; Pakiser, L. C.