An alternative explanation for the “Buried Channels” on Mars: The gravity signal from a sharp boundary on partially compensated, long-wavelength topography

• Published in: Geophysical research letters Vol. 31; no. 5; pp. L05701 - n/a
• Main Authors: Dombard, Andrew J., Searls, Mindi L., Phillips, Roger J.
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 16.03.2004; Blackwell Publishing Ltd
• Subjects: Gravitational fields; Mars; Planetology; Solar System Objects; Solid Surface Planets; Tectonics
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2003GL019162

A trough observed in the free‐air gravity of Mars along the edge of Tempe Terra has been interpreted as a large channel that has been completely buried by sediments. Here, we show that this trough is likely real and not a product of ringing in a truncated harmonic expansion, but that it is poorly resolved. A detailed examination of the high‐resolution topographic data displays no evidence for a buried channel, instead showing that the trough straddles the highlands‐lowlands boundary. As an alternative, we propose this gravity trough in a large way arises from the surface topography, due to an effect that occurs when there exists a relatively sharp boundary on a long‐wavelength, partially compensated feature.