Geologic disposal of high-level radioactive wastes; earth-science perspectives
No abstract available
Circular↗
Geology topics
A. W. England
Publications and source records attributed to A. W. England.
Spectral gradient of lunar radiobrightness: Heat flow or volume scattering?
Lunar heat flow cannot be derived unambiguously from the spectral gradient of the radiobrightness. Volume scattering of microwaves by rock clasts within the lunar regolith results in a spectral component in the 5- to 30-centimeter range of wavelengths that is a significant fraction of that resulting from lunar heat flow.
Journal of Research of the U.S. Geological Survey↗
Microwave radiometric survey of the San Joaquin nuclear project site, Kern County, California
An airborne microwave survey was made in the region of the San Joaquin nuclear project site near Bakersfield, Calif. The purpose of the study was to determine if the variability of soil emissivity due to moisture content is a valid near-surface expression of buried fault systems. The results showed the existence of linear-emissivity anomalies paralleling, and to some extent, overlying the Greeley and Pond-Poso Creek faults. The anomalies seem to be direct expressions of silt-filled, northwesterly trending channels of the Pond-Poso Creek-Tulare Lake distributary system. The location, orientation, and linearity of the distributary channels suggest an association with buried faults, but no relationship has yet been determined.
California↗
Relative influence upon microwave emissivity of fine-scale stratigraphy, internal scattering, and dielectric properties
The microwave emissivity of relatively low-loss media such as snow, ice, frozen ground, and lunar soil is strongly influenced by fine-scale layering and by internal scattering. Radiometric data, however, are commonly interpreted using a model of emission from a homogeneous, dielectric halfspace whose emissivity derives exclusively from dielectric properties. Conclusions based upon these simple interpretations can be erroneous. Examples are presented showing that the emission from fresh or hardpacked snow over either frozen or moist soil is governed dominantly by the size distribution of ice grains in the snowpack. Similarly, the thickness of seasonally frozen soil and the concentration of rock clasts in lunar soil noticeably affect, respectively, the emissivities of northern latitude soils in winter and of the lunar regolith. Petrophysical data accumulated in support of the geophysical interpretation of microwave data must include measurements of not only dielectric properties, but also of geometric factors such as finescale layering and size distributions of grains, inclusions, and voids.
Pure and Applied Geophysics PAGEOPH↗
Preliminary geologic investigation of the Apollo 16 landing site
The Apollo 16 landing site in the lunar central highlands encompassed terra plains and adjacent mountainous areas of hilly and furrowed terra. These morphologic units, representing important terrane types in the lunar highlands, had been interpreted as volcanic on most premission geologic maps. However, it became apparent during the mission that there are indeed few or no volcanic rocks or landforms at the site but rather that the area is underlain by a wide variety of impact-generated breccias.
Book chapter↗