Journal Article

Constraining Characteristic Morphological Wavelengths for Venus Using Baltis Vallis

Nimmo, F., Conrad, J. W.

2023

Overview

One of Venus' most enigmatic landforms is Baltis Vallis, the longest channel on the surface (∼7,000 km long). We identify a possible mid‐channel island that implies a south to north flow direction during formation. However, since the flow direction of Baltis Vallis is otherwise not well constrained, we analyze topographic conformity in both flow directions. In either case, topography appears to be altered across most analyzed wavelengths after the formation of Baltis Vallis. Fourier analysis shows two ranges of prominent wavelengths, 225 ± 15 km and ∼3,500 ± 1,200 km. The shorter wavelengths correspond to deformation belts that cross Venus' low plains. The longest is plausibly associated with the dynamic uplift wavelength of the crust by mantle plumes, but is less robustly detected. Higher resolution observations provided by the VERITAS and EnVision missions can help resolve the source location of Baltis Vallis and constrain if the longest wavelength postdated the canale's formation. Plain Language Summary Venus' surface is covered in a plethora of strange landforms, at least from the perspective of Earth. One of the longest is an about 7,000 km channel named Baltis Vallis, comparable to the Amazon and Nile rivers, but instead likely formed by volcanic processes. Baltis Vallis serves as a unique opportunity on Venus due to its length. The channel recorded surface altering processes in its topography, but we first check if the channel retained topographic information from when it initially formed. Our test shows that the topography has been altered by later processes and those processes should dominate the signal in analysis of the current topography. That analysis shows 2 length‐scales are overrepresented in the topography. The shorter length‐scale correspond to thin mountain range‐like features that cross Venus' low plains. The longest wavelength is plausibly associated with uplift of the crust by mantle plumes and this value will be useful when creating models of Venus' interior. Key Points A possible mid‐channel island in the longest channel on Venus implies a south to north flow direction We show that the topography and morphology of this channel was modified along most of its length Fourier analysis of the channel's topography shows a group of prominent wavelengths at ∼210–240 km, that we link to deformation belts

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Analysis / canali / characteristic wavelengths / Deformation / Direction / Earth mantle / Fourier analysis / geomophology / Landforms / Mantle plumes / Physical characteristics / Plumes / Rivers / tectonics / Topography / Uplift / Venus / Venus surface / Wavelength / Wavelengths