Geology topics

C. C. Allen

Publications and source records attributed to C. C. Allen.

3 recordsLinked to original sources

USGS2010

Diviner lunar radiometer observations of cold traps in the moon's south polar region

Diviner Lunar Radiometer Experiment surface-temperature maps reveal the existence of widespread surface and near-surface cryogenic regions that extend beyond the boundaries of persistent shadow. The Lunar Crater Observation and Sensing Satellite (LCROSS) struck one of the coldest of these regions, where subsurface temperatures are estimated to be 38 kelvin. Large areas of the lunar polar regions are currently cold enough to cold-trap water ice as well as a range of both more volatile and less volatile species. The diverse mixture of water and high-volatility compounds detected in the LCROSS ejecta plume is strong evidence for the impact delivery and cold-trapping of volatiles derived from primitive outer solar system bodies.

Science↗

USGS2009

The Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment

The Diviner Lunar Radiometer Experiment on NASA’s Lunar Reconnaissance Orbiter will be the first instrument to systematically map the global thermal state of the Moon and its diurnal and seasonal variability. Diviner will measure reflected solar and emitted infrared radiation in nine spectral channels with wavelengths ranging from 0.3 to 400 microns. The resulting measurements will enable characterization of the lunar thermal environment, mapping surface properties such as thermal inertia, rock abundance and silicate mineralogy, and determination of the locations and temperatures of volatile cold traps in the lunar polar regions.

Space Science Reviews↗

USGS2003

Biogeochemical sulphur cycle in an extreme environment - Life beneath a high arctic glacier, Nunavut, Canada

Unique springs discharge from the surface of a high arctic glacier, releasing H2S, and depositing native sulphur, gypsum, and calcite. A rare CaCO3 polymorph, vaterite, is also observed. Physical and chemical conditions of the spring water and surrounding environment, as well as mineralogical and isotopic signatures, argue for biologically mediated redox reactions controlling sulfur. Cell counts and DNA analyses, confirm bacteria are present in the spring system. ?? 2003 Elsevier Science B.V. All rights reserved.

Conference Paper↗