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Rectangular harmonic analysis applied to the geomagnetic field Rectangular harmonic analysis applied to the geomagnetic field

Spherical harmonic analysis of the earth's magnetic field is limited in the resolution that can be obtained. This limitation is caused by inadequacies of computers and of available data sets. The fundamental wavelength in spherical harmonic analysis is the circumference of the earth. To resolve wavelengths as short as 100 km would require a spherical harmonic analysis carried out to a...
Authors
L.R. Alldredge

Temporal and spatial variations in suspended matter in continental shelf and slope waters off the north-eastern United States Temporal and spatial variations in suspended matter in continental shelf and slope waters off the north-eastern United States

Seston in waters of Georges Bank originates primarily from biological production and from resuspension of bottom sediments. The concentrations of suspended matter observed on the central shoals are more influenced by storms than by seasonal changes. Winter storms produce highest concentrations of non-combustible material throughout the water column, and summer storms appear to increase...
Authors
Michael H. Bothner, Carol M. Parmenter, John D. Milliman

Geodetic measurement of crustal deformation on the San Andreas, Hayward, and Calaveras faults near San Francisco, California Geodetic measurement of crustal deformation on the San Andreas, Hayward, and Calaveras faults near San Francisco, California

Analysis of a geodetic network of 115 lines crossing the San Andreas, Hayward, and Calaveras faults in the vicinity of San Francisco Bay and measured repeatedly between 1970 and 1980 has revealed details about the accommodation of relative plate motion in this area. The most striking result is that the deformation is not uniformly distributed across the area. In the east bay, along the...
Authors
W.H. Prescott, Michael Lisowski, James C. Savage

Synchrotron radiation and its application to digital subtraction angiography Synchrotron radiation and its application to digital subtraction angiography

The intense synchrotron radiation produced at electron storage rings provides a new source of X-rays highly suited to iodine K-edge digital subtraction angiography. The high intensity and small angular divergence permit the radiation to be monochromatized by Bragg diffraction and made available in beams of small vertical size, of arbitrary horizontal width, and of tunable energy. The use...
Authors
E. Rubenstein, E.B. Hughes, L.E. Campbell, R. Hofstadter, Randolph L. Kirk, T.J. Krolicki, J.P. Stone, S. Wilson, H.D. Zeman, W.R. Brody

Reservoir analysis of the Denver earthquakes: A case of induced seismicity Reservoir analysis of the Denver earthquakes: A case of induced seismicity

Injection of fluid wastes into the fractured Precambrian crystalline bedrock beneath the Rocky Mountain Arsenal near Denver triggered earthquakes in the 1960's. An analysis, based on the assumption that fluid flow in the fractured reservoir can be approximated by flow in a porous medium, is presented. The configuration and hydrologic properties of the reservoir are determined from two...
Authors
Paul A. Hsieh, John D. Bredehoeft

Swash mark and grain flow Swash mark and grain flow

Swash marks composed entirely of coarse sand are commonly found on coarse-sand beaches. These swash marks are 10 to 30 centimeters in width and a few millimeters to one centimeter in height. Previous observations, mostly on finer-sand beaches, indicate swash marks are seldom over a few millimeters in height and are commonly composed of material readily floated by surface tension (e.g...
Authors
Sallenger

Prismatic slip of A12O3 single crystals below 1000°C in compression under hydrostatic pressure Prismatic slip of A12O3 single crystals below 1000°C in compression under hydrostatic pressure

Alumina single crystals were compressed perpendicular to the [0001] axis at a constant strain rate between 20° and 950°C. At r>200°C, failure was suppressed by_hydrostatic pressures of 500 to 1500 MPa. Prismatic slip {1120}〈1100〉 was deduced from optical observations of the lateral surfaces and from stress‐optical features in thin sections cut from the specimens. The critical resolved...
Authors
J. Castaing, J. Cadoz, Stephen H. Kirby

IASPEI workshop: Seismic modeling of laterally varying structures IASPEI workshop: Seismic modeling of laterally varying structures

During the past 10 years, significant progress has been made in the methods of collection and analysis of seismic reflection and refraction data. This progress has led to the development of new models for the structure and composition of the earth's crust, based on sophisticated analysis of numerous profiles in many areas of geologic importance. The third triannual meeting of the IASPEI
Authors
Walter D. Mooney
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