Revised lunar heat-flow values

Journal Article · Thu Jan 01 00:00:00 EST 1976 · Geochim. Cosmochim. Acta, Suppl.; (United States)

OSTI ID:5787569

Langseth, M G; Keihm, S J; Peters, K

Long-term subsurface temperature histories at the Apollo 15 and 17 heat-flow sites are analyzed to yield more reliable bulk thermal properties of the surrounding regolith material. Results indicate that the thermal conductivity of a large volume of the regolith material exterior to the probe-borestem contact zone lies within the range 0.9 to 1.3 x 10/sup -4/W cm/sup 10/K/sup -1/ at all four heat-flow stations. These results are 30 to 50% less than values previously reported which were based on short term measurements sensitive only to material within 2 to 3 cm of small probe heaters. The revised conductivity results lead to comparable revisions in the Apollo 15 and 17 heat-flow values. At the Hadley Rille and Taurus-Littrow sites, the revised heat-flow values are 2.1 and 1.6 ..mu..W/cm/sup 2/, respectively. Detailed analyses of topographic effects indicate that the Hadley Rille measurement is representative of the regional value, while at Taurus-Littrow, a small downward correction indicates that a value of 1.4 ..mu..W/cm/sup 2/ is the best estimate for the regional flux. Methods of estimating the regional variation in heat flow over the whole moon and consequent implications for the bulk lunar chemistry are discussed. One feasible approach, utilizing measured variations of surface thorium abundance and inferred crustal thicknesses yields an average global heat flux of 1.8 ..mu..W/cm/sup 2/ and a bulk uranium abundance of ppB. The need is emphasized for extended areal coverage of possible geochemical and heat-flow variations to minimize the uncertainties of global estimates.

• Research Organization: Columbia Univ., Palisades, NY
• OSTI ID: 5787569
• Journal Information: Geochim. Cosmochim. Acta, Suppl.; (United States), Journal Name: Geochim. Cosmochim. Acta, Suppl.; (United States)
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MOON
HEAT FLOW
ABUNDANCE
APOLLO PROJECT
GEOGRAPHICAL VARIATIONS
HEAT TRANSFER
NUMERICAL ANALYSIS
OVERBURDEN
THERMAL CONDUCTIVITY
THERMAL DIFFUSIVITY
THORIUM
TOPOGRAPHY
URANIUM
ACTINIDES
ELEMENTS
ENERGY TRANSFER
MATHEMATICS
METALS
PHYSICAL PROPERTIES
SATELLITES
THERMODYNAMIC PROPERTIES
VARIATIONS
640107* - Astrophysics & Cosmology- Planetary Phenomena