Large-scale topography of Io: implications for internal structure and heat transfer.

R. W. Gaskell, S. P. Synnott, Alfred S. McEwen, G. C. Schaber

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Abstract

New stereographic techniques were applied to Voyager 1 images to determine the shape and large-scale topopgraphy of Io. The best- fit triaxial figure has semiaxes of 1830.0, 1818.7 and 1815.3 km with random errors of about 200 m. Systematic navigation and optical system errors are comparable. The resulting figure is consistent with a differentiated satellite in hydrostatic equilibrium. The deviation from homogeneity could be explained by the presence of an iron core with a radius of about 800 km. If the large-scale topography is positively correlated with heat flow, then the global pattern of basins and swells suggests tidal dissipation in a molten or partialy molten asthenosphere rather than in the mantle. Areas higher than 1 km may consist of low-density crustal materials. Media Regio, the largest such region, is centered near the equator at longitude 70o. -from Authors

Original languageEnglish (US)
Pages (from-to)581-584
Number of pages4
JournalGeophysical Research Letters
Volume15
Issue number6
Publication statusPublished - 1988
Externally publishedYes

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ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)

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