Astronomy and Astrophysics – Astronomy
Scientific paper
Nov 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994icar..112..104k&link_type=abstract
Icarus (ISSN 0019-1035), vol. 112, no. 1, p. 104-116
Astronomy and Astrophysics
Astronomy
31
Compensation, Equatorial Regions, Geoids, Highlands, Isostasy, Topography, Venus (Planet), Venus Surface, Astronomical Models, Earth (Planet), Least Squares Method, Lithosphere, Planetary Crusts, Power Spectra, Regression Analysis, Spherical Harmonics
Scientific paper
Spherical harmonic models for Venus' global topography and gravity incorporating Magellan data are used to test isostatic compensation models in five 30 deg x 30 deg regions representative of the main classes of equatorial highlands. The power spectral density for the harmonic models obeys a power-law scaling with spectral slope Beta approximately 2 (Brown noise) for the topography and Beta approximately 3 (Kaula's law) for the geoid, similar to what is observed for Earth. The Venus topography spectrum has lower amplitudes than Earth's which reflects the dominant lowland topography on Venus. Observed degree geoid to topography ratios (GTRs) on Venus are significantly smaller than degree GTRs for uncompensated topography, indicative of substantial compensation. Assuming a global Airy compensation, most of the topography is compensated at depths greater than 100 km, suggesting a thick lithosphere on Venus. For each region considered we obtain a regional degree of compensation C from a linear regression of Bouguer anomaly versus Bouguer gravity data. Geoid anomaly (N) versus topography variation (h) data for each sample were compared, in the least-squares sense, to theoretical correlations for Pratt, Airy, and thermal thinning isostasy models yielding regional GTR, zero-elevation crustal thickness (H), and zero elevation thermal lithosphere thickness (yL(sub 0), respectively. We find the regional compensation to be substantial (C approximately 52-80%), and the h, N data correlations in the chosen areas can be explained by isostasy models applicable on the Earth and involving variations in crustal thickness (Airy) and/or lithospheric (thermal thinning) thickness. However, a thick crust and lithosphere (yL(sub 0) approximately 300 km) must be assumed for Venus.
Kucinskas Algis B.
Turcotte Donald L.
No associations
LandOfFree
Isostatic compensation of equatorial highlands on Venus does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Isostatic compensation of equatorial highlands on Venus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Isostatic compensation of equatorial highlands on Venus will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1024544