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Detailed Reference Information |
Hoogenboom, T., Smrekar, S.E., Anderson, F.S. and Houseman, G. (2004). Admittance survey of type 1 coronae on Venus. Journal of Geophysical Research 109: doi: 10.1029/2003JE002171. issn: 0148-0227. |
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In this study, we analyze Magellan gravity and topography data for Type 1 coronae on Venus to estimate crustal thickness (Zc), elastic thickness (Te), and apparent depth of compensation (ZL). We examine the free-air admittance for all 103 Type 1 coronae (defined as having greater than 50% complete fracture annuli) that are resolved in the gravity data. A spatio-spectral method is used to calculate a localized admittance signature of each corona from a global admittance map. This method extracts spectral information from a region in space whose area is varied as a function of degree to make it large enough to yield robust results at every individual wavelength. Elastic flexure models with either bottom- or top-loading compensation are used to fit the data. The estimated lithospheric flexural parameters span the range obtained for other topographic features on Venus, suggesting that the lithosphere on which coronae form is variable. We find no significant difference in lithospheric properties between Type 1 and 2 coronae. Fifty-four percent of all coronae are consistent with local isostasy, which may indicate that they are no longer active. Very few coronae with dome or plateau morphologies have a bottom-loading signature or the small Te and large ZL expected if a mantle plume were present. Approximately 71% have ZL estimates less than 70 km, indicating that compensation probably occurs within the crustal layer. We find no systematic relationship between Te or Zc and corona diameter, as would be expected for the spreading-drop model of formation. |
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Abstract |
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Keywords
Planetology, Solid Surface Planets, Interiors, Planetology, Solid Surface Planets, Tectonics, Planetology, Solar System Objects, Venus, Tectonophysics, Dynamics, convection currents and mantle plumes, Tectonophysics, Dynamics, gravity and tectonics, Venus, corona, gravity, admittance |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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