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Estimating heat capacity and heat content of rocks Estimating heat capacity and heat content of rocks

New heat-capacity measurements are reported for four rock types; Westerly granite from Bradford, RI, andesite from Lake County, OR, peridotite from Sonoma County, CA, and basalt from the Columbia River Group. Measurements were made on powders of the rocks in the temperature range of 340 to about 1000 K. Our measured heat-capacity values for rocks and other measurements of heat capacity...
Authors
Eugene C. Robertson, Bruch S. Hemingway

Nonperiodic eddy pulsations Nonperiodic eddy pulsations

Recirculating flow in lateral separation eddies is typically weaker than main stem flow and provides an effective environment for trapping sediment. Observations of recirculating flow and sedimentary structures demonstrate that eddies pulsate in size and in flow velocity even when main stem flow is steady. Time series measurements of flow velocity and location of the reattachment point...
Authors
David M. Rubin, Richard R. McDonald

Strain accumulation along the Laguna Salada Fault, Baja California, Mexico Strain accumulation along the Laguna Salada Fault, Baja California, Mexico

Strain accumulation observed over the 1978–1991 interval in a 30×100 km aperture trilateration network spanning the Laguna Salada fault is described by the principal strain rates 0.101±0.012 strain/yr N80°E±2° and −0.021±0.012 strain/yr N10°W±2°, extension reckoned positive. These strain accumulation rates have been corrected to remove coseismic effects of the nearby 1979 Imperial Valley...
Authors
James C. Savage, Michael Lisowski, N.E. King, W.K. Gross

Postseismic deformation following the 1989 (M = 7.1): Loma Prieta, California, earthquake Postseismic deformation following the 1989 (M = 7.1): Loma Prieta, California, earthquake

Postseismic deformation along a 90‐km profile bisecting the projected surface trace of the coseismic rupture of the 1989 Loma Prieta earthquake has been monitored by frequent GPS surveys for 3.3 years following the earthquake. In addition to the expected deformation associated with secular strain accumulation on the San Andreas and Calaveras faults, deformation associated with...
Authors
James C. Savage, Michael Lisowski, Jerry L. Svarc

Strain accumulation north of Los Angeles, California, as a function of time, 1977–1992 Strain accumulation north of Los Angeles, California, as a function of time, 1977–1992

No significant change in the rate of strain accumulation in a 40×120 km trilateration network spanning the San Gabriel mountains was observed from 1977.5 to 1991.8 despite an apparent increase in seismicity (ML > 4.5) beginning in late 1987 in the northern Los Angeles basin immediately to the south. The observed deformation (0.13±0.01 µstrain/yr right‐lateral shear across a vertical...
Authors
James C. Savage, Michael Lisowski

Estimates of site-dependent response spectra for design (methodology and justification) Estimates of site-dependent response spectra for design (methodology and justification)

Recent borehole-geotechnical data and strong-motion measurements constitute a new empirical basis to account for local geological conditions in earthquake-resistant design and site-dependent, building-code provisions. They provide new unambiguous definitions of site classes and rigorous empirical estimates of site-dependent amplification factors in terms of mean shear-wave velocity. A...
Authors
Roger D. Borcherdt

Venus cartography Venus cartography

The entire surface of the planet Venus is being mapped at global and regional scales (1:50,000,000 through 1:1,500,000) with synthetic aperture radar (SAR), radar altimeter, and radiometer measurements of physical properties from the Magellan spacecraft. The mapping includes SAR image mosaics, shaded relief maps, and topographic contour overlays made from altimetry data and by...
Authors
R. M. Batson, Randolph L. Kirk, Kathleen Edwards, H.F. Morgan

Evaluation of an empirical radar backscatter model for predicting backscatter characteristics of geologic units at Pisgah Volcanic Field, California Evaluation of an empirical radar backscatter model for predicting backscatter characteristics of geologic units at Pisgah Volcanic Field, California

Comparison of radar backscatter coefficients (σ°, in dB), calculated by using the empirical model of Oh et al. [1992], to σ° extracted from AIRSAR data of four geologic units at Pisgah shows that the model predicts measured σ°vv and σ°hv to within ±3 dB. The model predicts higher σ°hh than those observed. For smooth surfaces (rms height=s, s
Authors
Lisa R. Gaddis
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