Simulations that match the observed topography of Venus suggest the planet's interior remains restless, with major rift systems either active today or having operated within the past few tens of millions of years.
A study released in Nature Geoscience shows that the broad, elevated flanks alongside rifts such as Ganis Chasma, Dali Chasma and Devana Chasma can only be explained by recent or ongoing extension. The work rests on careful comparison between spacecraft data and numerical models run under realistic Venusian conditions.
Three-dimensional thermomechanical simulations demonstrate that these wide rift flanks develop while rifting proceeds or shortly after it ends. Once extension ceases, the flanks gradually relax and flatten over periods of 10 to 100 million years. The presence of pronounced uplifts therefore implies the process has not long been dormant.
The results help us to better assess the tectonic activity on Venus.
That assessment comes from Taras Gerya, professor of geodynamics at ETH Zurich, who led the research alongside lead author Xi Yang. Their models require extension rates between 3 and 10 centimetres per year, noticeably higher than many earlier estimates for the planet.
To reproduce the observed heights and widths, the simulations call for a relatively thick thermal lithosphere and a strong crust whose behaviour matches dry diabase or mafic granulite. These mechanical assumptions align with radar images from NASA’s Magellan mission, which first mapped the striking rift topography.
The findings carry implications beyond simple dating. They suggest recent vigorous mantle plume activity may be linked to the rifting, painting a picture of a world whose geology has remained lively on timescales that overlap with the emergence of complex life on Earth.
