EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evolution of Venusian rifts: Insights from Numerical Modeling

Alessandro Regorda1, Cedric Thieulot2, Iris van Zelst3, Zoltán Erdös4,5, Julia Maia6, and Susanne Buiter4,5
Alessandro Regorda et al.
  • 1Università degli Studi di Milano, Scienze della Terra 'Ardito Desio', Milano, Italy (
  • 2Department of Earth Sciences, Utrecht University, Utrecht, The Netherlands
  • 3Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany
  • 4The Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences, Potsdam, Germany
  • 5Tectonics and Geodynamics, RWTH Aachen University, Aachen, Germany
  • 6Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France

Venus is a terrestrial planet with dimensions similar to the Earth and, although it is generally assumed that it does not host plate-tectonics, there are indications that Venus might have experienced, or still does experience, some form of tectonics. In fact, there are widespread observations of rifts on Venus called ‘chasma’ (plural ‘chasmata’), from radar-image interpretation of normal-fault-bounded graben structures (Harris & Bédard, 2015).

The rifts on Venus have been likened to continental rifts on Earth such as the East African (e.g., Basilevsky & McGill, 2007) and Atlantic rift system prior to ocean opening (Graff et al., 2018), even if they are commonly wider than their terrestrial equivalent (e.g., Foster & Nimmo, 1996). However, despite being a prominent feature on its surface, little is known about the mechanisms responsible for creating rifts on Venus beyond the assumption that they are extensional features (Magee & Head, 1995).

Since rifting on Earth in both continental and oceanic settings has been extensively studied through modeling, we adapted 2D thermo-mechanical numerical models of rifting on Earth to Venus in order to study how rifting structures observed on the Venusian surface could have been formed. More specifically, we investigated how rifting evolves under the high pressure and temperature conditions of the Venusian surface and the lithospheric structure proposed for Venus.

Our results show that a strong crustal rheology such as diabase is needed to localize strain and to develop a rift under the harsh surface conditions of Venus. The evolution of the rift formation is predominantly controlled by the crustal thickness, with a 25 km-thick diabase crust required to produce mantle upwelling and melting. Lastly, we compared the surface topography produced by our models with the topography profiles of different Venusian chasmata. We observed a good fit between models characterised by different crustal thicknesses and the Ganis and Devana Chasmata, suggesting that differences in rift features on Venus could be due to different crustal thicknesses.



Basilevsky, A. T., & McGill, G. E. (2007). Surface evolution of Venus. In Exploring Venus as a terrestrial planet (p. 23-43). American Geophysical Union. doi: 10.1029/176GM04

Foster, A., & Nimmo, F. (1996). Comparisons between the rift systems of East Africa, Earth and Beta Regio, Venus. Earth and Planetary Science Letters, 143 (1), 183-195. doi: 10.1016/0012-821X(96)00146-X

Graff, J., Ernst, R., & Samson, C. (2018). Evidence for triple-junction rifting focussed on local magmatic centres along Parga Chasma, Venus. Icarus, 306 , 122-138. doi: 10.1016/j.icarus.2018.02.010

Harris, L. B., & Bédard, J. H. (2015). Interactions between continent-like ‘drift’, rifting and mantle flow on Venus: gravity interpretations and Earth analogues. In: Volcanism and Tectonism Across the Inner Solar System. Geological Society of London. doi: 10.1144/SP401.9

Magee, K. P., & Head, J. W. (1995). The role of rifting in the generation of melt: Implications for the origin and evolution of the Lada Terra-Lavinia Planitia region of Venus. Journal of Geophysical Research: Planets, 100 (E1), 1527-1552. doi: 10.1029/94JE02334

How to cite: Regorda, A., Thieulot, C., van Zelst, I., Erdös, Z., Maia, J., and Buiter, S.: Evolution of Venusian rifts: Insights from Numerical Modeling, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-15108,, 2023.