Pancake domes on Venus have puzzled scientists for years. Imagine these weirdly perfect, steep-sided volcanoes rising from Venus’ surface like circular welts. These dome-shaped structures, known as “pancake domes,
” cover tens of miles but are just half a mile in height, resembling flattened versions of Hawaii’s Mauna Loa.
While the formation of these pancake domes has long been a mystery, a recent study suggests that Venus’ bendy crust plays a significant role in shaping these unique geological features. Madison Borrelli, a postdoctoral researcher at the Georgia Institute of Technology and lead author of the study, explained this intriguing connection.
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One factor that many previous studies hadn’t considered was the ‘bendiness,’ or the flexure, of Venus’ upper crust,” Borrelli shared. The planet’s surface behaves like an orange’s skin in certain areas, dimpling under heavy loads. This flexural property could leave distinct signs around pancake domes where the crust buckles upwards.
The research team focused on studying one specific dome on Venus called Narina Tholus to understand how a bendy crust influences pancake dome formation. Using topographical data collected by NASA’s Magellan mission in the 1990s, they created a virtual model of Narina Tholus and simulated lava flows atop both flexible and rigid crusts.
The results were fascinating. Domes formed on a bendy crust closely resembled real-life pancake domes with flat tops and steep sides. The bulge surrounding the dome prevented lava from flowing further, causing it to accumulate and solidify into dome-like structures over hundreds of thousands of years.
However, it wasn’t just about the crust’s flexibility; lava density also played a crucial role in shaping these domes. The study found that only high-density lavas produced domes with the right shape and characteristic flexural signatures similar to those observed near Narina Tholus.
Borrelli expressed hope that future missions to Venus would provide more high-resolution data to validate their findings across various volcanic structures on the planet. This additional data could help determine the exact type of lava responsible for forming these enigmatic pancake domes.
While most Venusian volcanoes are believed to erupt basaltic lava akin to Mauna Loa’s composition, researchers couldn’t rule out other types such as rhyolitic and andesitic lavas commonly seen on Earth’s volcanoes like Mount St. Helens. Discovering diverse lava types on Venus could offer insights into its tectonic history, magmatic processes, and even past hydrological conditions.
In conclusion, unraveling the secrets behind Venus’ pancake domes is not just about understanding its geology but also offers glimpses into planetary processes beyond our own Earthly experiences.
