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

Abstract

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.