NASA Technical Reports Server (NTRS) 19930005100: Papers presented to the International Colloquium on Venus

154 Pages·14.4 MB·English

by  NASA Technical Reports Server (NTRS)

NARA-CO-19007o
Papers Presented to the
INTERNATIONAL
COLLOQUIUM
ON
) I t_
c;
r" i 1 i*-
VENUS
,...4
I "r I
_._ _._. ,.-,- (j
,-"4
o
3
:. ,.-.,
j ,-
' t ? e,-
_L "r ",
)
I _7 _a
{ i
2 -3--
AUGUST 10-12, 1992
PASADENA, CALIFORNIA

PAPERS PRESENTED TO THE
INTERNATIONAL COLLOQUIUM ON VENUS
August 10-12, 1992
Pasadena, California
Sponsored by
National Aeronautics and Space Administration
" Jet Propulsion Laboratory
Lunar and Planetary Institute
Russian Academy of Sciences
International Union of Geological Sciences
International Space Year
LPI Contribution No. 789
Compiled in 1992 by
Lunar and Planetary Institute
3600 Bay Area Boulevard
Houston TX 77058-1113
Material in this volume may be copied without restraint for library, abstract service, education, or personal
research purposes; however, republication of any paper or portion thereof requires the written permission of the
authors as well as appropriate acknowledgment of this publication.
The Lunar and Planetary Institute isoperated by the Universities Space Research Association under Contract No.
NASW-4574 with the National Aeronautics and Space Administration.
PREFACE
This volume contains short papers that have been accepted for the International
Colloquium on Venus, August 10-12, Pasadena, California. The Program Committee
consisted of R. Stephen Saunders (Jet Propulsion Laboratory) and Sean C. Solomon
(Massachusetts Institute of Technology), chairmen; Raymond Arvidson (Washington
University); Valery L. Barsukov, Mikhail Yu. Zolotov, Alexander T. Basilevsky
(Vernadsky Institute); Vassily Moroz (Institute for Space Research); Donald Bo Campbell
(Cornell University); Thomas Donahue (University of Michigan); James W. Head HI
(Brown University); Pamela Jones (Lunar and Planetary Institute); Mona Jasnow,
Andrew Morrison, Timothy Parker, Jeffrey Plaut, Ellen Stofan, Tommy Thompson,
Cathy Weitz (Jet Propulsion Laboratory); Gordon Pettengill (Massachusetts Institute
of Technology); and Janet Luhmann (University of California, Los Angeles).
Logistics and administrative support were provided by the Program Services Depart-
ment staff at the Lunar and Planetary Institute. This volume was prepared by the Publica-
tions Services Department staff at the Lunar and Planetary Institute.

TABLE OF CONTENTS
Venus Radar Mapping from the Venera 15 and 16 Spacecrafts: Results and Restrictions
E. L. Akim, A. I. Zakharov, and A. P. Krivtsov ........................................................................... 1
Local-Time Asymmetries in the Venus Thermosphere
M. J. Alexander, A. I. F. Stewart, and S. W. Bougher .................................................................. 1
Ringed Impact Craters on Venus: An Analysis from Magellan Images
J. S. Alexopoulos and W. B. McKinnon ....................................................................................... 2
Is Ishtar Terra a Thickened Basaltic Crust?
J. Arkani-Hamed .......................................................................................................................... 4
Constraints on the Thermal Evolution of Venus Inferred from Magellan Data
J. Arkani-Hamed, G. G. Schaber, and R. G. Strom ....................................................................... 5
Surface Processes on Venus
R. E. Arvidson ............................................................................................................................. 6
Shield Fields: Concentrations of Small Volcanic Edifices on Venus
J. C. Aubele and L. S. Crumpler .................................................................................................. 7
The Geology of the Venera/Vega Landing Sites
A. T. Basilevsky and C. M. Weitz ................................................................................................ 8
Global Deformation on the Surface of Venus
F. Bilotti, C. Connors, and J. Suppe ........................................................................................... 10
Coldspots or Hotspots? The Origin of Plateau-shaped Highlands on Venus
D. L. Bindschadler. .................................................................................................................... 12
Monte Carlo Modeling of the Resurfacing of Venus
M. A. Bullock, D. H. Grinspoon, and J. W. Head ....................................................................... 14
Debris Avalanches and Slumps on the Margins of Volcanic Domes on Venus:
Characteristics of Deposits
M. H. Bulmer, J. E. Guest, K. Beretan, G. Michaels, and S. Saunders ........................................ 14
Mixed-Valence Iron Minerals on Venus: Fe2*-Fe z+Oxides and Oxy-silicates
Formed by Surface-Atmosphere Interactions
R. G. Burns and D. W. Straub .................................................................................................... 15
Thermal Buoyancy on Venus: Preliminary Results of Finite Element Modeling
J. D. Burt and J. W. Head ........................................................................................................... 17
4
Y _j. .1 o.rawa
PRECEt')_,NG P._GE BLANK NOT RLMED v
Erosion Vs. Construction: The Origin of Venusian Channels
D. B. J. Bussey and J. E. Guest .................................................................................................. 18
Polarization Properties and Earth-based Radar Measurements of Venus
in the Post-Magellan Era
D. B. Campbell .......................................................................................................................... 19
Bright Crater Ouo"lows: Possible Emplacement Mechanisms
D. J. Chadwick, G. G. Schaber, R. G. Strom, and D. M. Duval .................................................. 20
Image Processing and Products for the Magellan Mission to Venus
J. Clark, D. Alexander, P. Andres, S. Lewicki, and M. McAuley ............................................... 22
The Thermosphere and Ionosphere of Venus
T. E. Cravens ............................................................................................................................. 22
Near4nfrared Oxygen Airglow from the Venus Nightside
D. Crisp, V. S. Meadows, D. A. Allen, B. Bezard, C. DeBergh,
and J.-P. Maillard ...................................................................................................................... 23
Global Correlation of Volcanic Centers on Venus with Uplands and
with Extension: Influence of Mantle Convection and Altitude
L. S. Crumpler, J. W. Head, and J. C. Aubele ............................................................................ 25
The Spin Vector of Venus Determined from Magellan Data
M. E. Davies, T. R. Colvin, P. G. Rogers, P. W. Chodas, and W. L. Sjogren ............................. 27
Monte Carlo Computer Simulations of Venus Equilibrium and Global
Resurfacing Models
D. D. Dawson, R. G. Strom, and G. G. Schaber ......................................................................... 27
Methane Measurement by the Pioneer Venus Large Probe Neutral
Mass Spectrometer
T. M. Donahue and R. R. Hodges Jr .......................................................................................... 29
Viscoelastic Relaxation of Venusian Coronae and Mountain Belts:
Constraints on Global Heat Flow and Tectonism
I. Duncan and A. Leith .............................................................................................................. 29
Flexural Analysis of Uplifted Rift Flanks on Venus
S. A. Evans, M. Simons, and S. C. Solomon .............................................................................. 30
Understanding the Variation in the Millimeter-Wave Emission of Venus
A. K. Fahd and P. G. Steffes ...................................................................................................... 32
Radar Scattering Properties of Pancakelike Domes on Venus
P. G. Ford and G. H. Pettingill ................................................................................................... 34
vi
Sequential Deformation of Plains Along Tessera Boundaries on Venus:
Evidence from Alpha Regio
M. S. Gilmore and J. W. Head ................................................................................................... 34
Venusian Hydrology: Steady State Reconsidered
D. H. Grinspoon ......................................................................................................................... 36
Determining Stress States Using Dike Swarms: The Lauma Dorsa Example
E. B. Grosfils and J. W. Head .................................................................................................... 37
Venus Mesospheric Winds and the Carbon Monoxide Bulge
M. A. Gurwell, D. O. Muhleman, and K. P. Shah ...................................................................... 39
Tectonics and Volcanism of Eastern Aphrodite Terra: No Subduction, No Spreading
V. L. Hansen, M. Keep, R. R. Herrick, and R. J. Phillips ........................................................... 40
Western Aphrodite Terra, Tectonics, Geology, and Line-of-Sight Gravity
J. E. Hays and P. Morgan ........................................................................................................... 41
Venus Volcanism: A Global Overview from Magellan Data
J. W. Head, L. S. Crumpler, J. C. Aubele, and the Magellan Team ............................................ 43
Chemical Differentiation on One-Plate Planets: Predictions and Geologic
Observations for Venus
J. W. Head, E. M. Parmentier, and P. C. Hess ............................................................................ 45
Dynamics of the Venus Atmosphere
A. P. Ingersoll ............................................................................................................................ 47
j
Largest Impact Craters on Venus
B. A. Ivanov, C. M. Weitz, and A. T. Basilevsky ....................................................................... 48
Venusian Extended Ejecta Deposits as Time-Stratigraphic Markers
N. R. Izenberg ............................................................................................................................ 49
Long-Term Variations in Abundance and Distribution of Sulfuric Acid Vapor
in the Venus Atmosphere Inferred from Pioneer Venus and Magellan Radio
Occultation Studies
J. M. Jenkins and P. G. Steffes ................................................................................................... 50
Variations in Lithospheric Thickness on Venus
C. L. Johnson and D. T. Sandwell .............................................................................................. 51
Igneous and Tectonic Evolution of Venusian and Terrestrial Coronae
J. S. Kargel and G. Komatsu ...................................................................................................... 52
vii
Venus:TheCasefor a WetOrigin andaRunawayGreenhouse
J. F. Kasting ............................................................................................................................... 54
Venus Tectonic Styles and Crustal Differentiation
W. M. Kaula and A. Lenardic .................................................................................................... 55
Large Shield Volcanos on Venus: The Effect of Neutral Buoyancy
Zone Development on Evolution and Altitude Distribution
S. Keddie and J. Head .............................................................................................................. 56
Mantle Plumes on Venus Revisited
W. S. Kiefer ............................................................................................................................... 57
Pioneer Venus Polarimetry and Haze Optical Thickness
W. J. J. Knibbe, W. M. F. Wauben, L. D. Travis, and J. W. Hovenier ....................................... 59
Venus Internal Magnetic Field and Its Interaction with the Interplanetary
Magnetic Field
W. C. Knudsen .......................................................................................................................... 60
Venusian Sinuous Rilles
G. Komatsu and V. R. Baker ...................................................................................................... 60
Radiation Pressure: A Possible Cause for the Superrotation of the
Venusian Atmosphere
J. L. Krause ............................................................................................................................... 61
Large-Volume Lava Flow Fields on Venus: Dimensions and Morphology
M. G. Lancaster, J. E. Guest, K. M. Roberts, and J. W. Head ..................................................... 62
Derivation of Surface Properties from Magellan Altimetry Data
A. J. Lovell, F. P. Schloerb, and G. E. McGill ........................................................................... 64
The Solar Wind Interaction with Venus
J. G. Luhmann ........................................................................................................................... 65
Extensive Lava Flow Fields on Venus: Preliminary Investigation of Source
Elevation and Regional Slope Variations
K. Magee-Roberts, J. W. Head, J. E. Guest, and M. G. Lancaster .............................................. 65
Wrinkle Ridges on Venusian Plains: Indicators of Shallow Crustal Stress
Orientations at Local and Regional Scales
G. E. McGill .............................................................................................................................. 67
Estimates of Elastic Plate Thicknesses Beneath Large Volcanos on Venus
P. J. McGovern and S. C. Solomon ............................................................................................ 68
°.°
VIII