Evidence of Topographic Change Recorded by Lava Flows at Atete and Aruru Coronae on Venus

Coronae are quasi‐circular volcano‐tectonic features on Venus. Four critical observations have been identified within the coronae population, including fracture annuli, a wide range of diameters, complex and varied topography, and various types of associated volcanic features. Geophysical models hav...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of geophysical research. Planets 2023-11, Vol.128 (11), p.n/a
Hauptverfasser: Tucker, Wesley S., Dombard, Andrew J.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Coronae are quasi‐circular volcano‐tectonic features on Venus. Four critical observations have been identified within the coronae population, including fracture annuli, a wide range of diameters, complex and varied topography, and various types of associated volcanic features. Geophysical models have attempted to replicate their formation from a variety of lithospheric processes but struggle to recreate all four of the critical observations. Volcanism is an often overlooked characteristic in corona formation models. Paleotopographic techniques are applied to lava flows associated with Atete Corona and Aruru Corona in the Beta‐Atla‐Themis region to investigate post‐emplacement changes in topography. Our results indicate marked divergence between lava flow orientation and the modern slope within the fracture annuli of the coronae. Intra‐annular flows at Atete Corona were emplaced on a surface that was reoriented by up to ∼180°. Intra‐annular flows at Aruru Corona were emplaced on a surface that was reoriented between 90° and 145°. Lava flows on the flanks of both coronae diverge less than those within the fractures. This finding suggests a progression of volcanism that starts at the interior of the corona and migrates outward to the fracture annuli. The role of volcanism, both intrusive and extrusive, is likely to play a more substantial role in the corona formation. Incorporating melt migration into geophysical models could significantly enhance our comprehension of the processes underlying the formation of coronae. Plain Language Summary Coronae are circular structures found only on the surface of Venus with characteristics of both volcanoes and tectonically formed features. There are four key observations have been identified about these structures: they are surrounded by a circle of fractures, they come in a wide range of sizes, they vary in the shape of their topography, and they are often associated with volcanic activity. Current models that attempt to explain their formation through processes within Venus' outer shell (or lithosphere) have difficulty accounting for all these observations. In this study, lava flows related to two coronae, Atete Corona and Aruru Corona, are examined using techniques that provide information on how the surface changes over time. Our results show that there is a significant mismatch between the direction of the lava flows and the slopes they are on top of. In some places, the lava flows appeared to have “flowed” uphill.
ISSN:2169-9097
2169-9100
DOI:10.1029/2023JE007971