Constraining the Interior Structure of Crustal Plateaus on Venus in the Context of Future Space Missions

Kurzfassung

Crustal plateaus are large, high-elevation features on Venus that are associated with the strongly deformed tessera terrains. They present positive low-magnitude gravity anomalies, and are stratigraphically the oldest surfaces on Venus [1]. Previous investigations of the gravity and topography signatures of these plateaus are consistent with shallow support via crustal thickening [e.g., 2, 3]. Data from Venus Express show that the Alpha Regio is associated with low emissivity anomalies, which could indicate felsic compositions [4]. Joint interpretation of these datasets (Fig. 1) suggests that crustal plateaus may represent analogues to Earth’s continents [e.g., 4,5], which would have major implications for understanding Venus’ tectonic and geodynamic evolution. Investigating the origin and evolution of these features is among the main objectives of upcoming missions to Venus. The goal of this study is to quantify the extent to which future gravity datasets, specifically those to be obtained by the VERITAS mission [6,7], will help to constrain the geophysical properties of plateaus. We generate synthetic data adopting the resolution and noise levels expected for the VERITAS gravity model. We quantify the improvement of crustal thickness and lithospheric elastic thickness estimates in comparison to analyses using Magellan data. In addition, we investigate the potential of the upcoming gravity dataset to obtain constraints on the crustal density of the plateaus. This quantity is of particular importance because felsic and mafic materials have relatively low and high densities, respectively. Hence, these estimates could be combined with surface emissivity constraints to investigate the crustal composition of these regions.