An outgassing release factor for nonradiogenic volatiles on Mars

Conference · Thu Aug 30 00:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

OSTI ID:5453036

Scambos, T A; Jakosky, B M ^[1]

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1. Univ. of Colorado, Boulder (USA)

The release factor for outgassing of nonradiogenic volatiles (e.g., water) on Mars since the end of accretion and heavy bombardment is estimated to be 0.017-0.112. The estimate is based on the {sup 40}Ar release factor (which is 0.012-0.040) and a correction coefficient derived from this history of volcanism on Mars. Volcanism is used as a measure of outgassing activity, and studies of Martian volcanic activity through time by Greeley (1987) and Tanaka et al. (1988) are used to calculate the correction coefficient. The calculated nonradiogenic release coefficients are 1.4-2.8; i.e., the release of nonradiogenic volatiles is 1.4-2.8 times the {sup 40}Ar release factors. The calculation assumes that Mars has not lost {sup 40}Ar since accretion ended and that the nonradiogenic volatiles are released with equal efficiency and by the same events as {sup 40}Ar. Interpretation of the result is highly dependent on the fate of early accreted surficial volatiles. If the present atmosphere and surficial volatile inventory is entirely secondary, i.e., released by outgassing after accretion, the release factors calculated may be used as an approximate ratio of present surficial inventory to total volatile content. If Mars retained some primary surficial inventory in addition to secondary volatiles, then the release factors pertain to the secondary fraction only, and estimates of the contribution of volatiles released by volcanism since accretion may be used to constrain the volatile content of the postaccretionary Martian mantle.

• OSTI ID: 5453036
• Report Number(s): CONF-9001119-; CODEN: JGREA; TRN: 91-023795
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:B9; Conference: 4. international conference on Mars, Tucson, AZ (United States), 10-13 Jan 1990; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MARS PLANET
CHEMICAL COMPOSITION
VOLATILE MATTER
DEGASSING
ARGON 40
CORRECTIONS
PLANET-SYSTEM ACCRETION
PLANETARY ATMOSPHERES
PLANETARY EVOLUTION
VOLCANISM
WATER
ARGON ISOTOPES
ATMOSPHERES
EVEN-EVEN NUCLEI
HYDROGEN COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MATTER
NUCLEI
OXYGEN COMPOUNDS
PLANETS
SOLAR SYSTEM EVOLUTION
STABLE ISOTOPES
640107* - Astrophysics & Cosmology- Planetary Phenomena