A trio of scientists from the Georgia Institute of Technology, Université de Lyon, and Arizona State University, respectively, has found that a likely reason flat pancake-like volcanoes form on Venus’ surface is the planet has an elastic lithosphere and volcanoes that emit dense lava.

In their paper published in the Journal of Geophysical Research: Planets, M. E. Borrelli, C. Michaut, and J. G. O’Rourke describe how they used data collected by NASA’s Magellan mission in the 1990s, to simulate how one such flat-topped dome could have come about and what they learned by doing so.

Planetary scientists have been wondering for many years how the oddly shaped volcanic domes came to exist on the surface of Venus. With their flat shapes and steep sides, they are unlike any volcanoes seen on Earth—they look much more like pancakes than cones. To learn more, the research trio took a unique approach. They attempted to simulate how just one of them might have come about.

To create their simulation, the research trio collected surface data from NASA’s Magellan craft, which used radar to map the surface of the planet from 1990 to 1994. In doing so, they focused most specifically on Narina Tholus because it had the highest resolution data.

The dome is big, they noted, measuring approximately 55 kilometers wide. To find out how it might have formed, they used Magellan data and data from other known geological formations, including the materials that make up Venus’s crust.

The result was a virtual model of the dome that simulated its birth and growth. To get the simulation to generate the dome as it exists in reality, the researchers had to find the right viscosity of the lava coming from below the surface—they tried several options and also varied the rigidity of the lithosphere.

After tinkering with their model, they found the only conditions that led to the shape of the domes on Venus were that the lithosphere was somewhat bendy and the lava was dense. The elastic crust, they note, allowed the dome to form over a long period of time, which coincided with the rate of dense lava flow. The flat tops came about due to gravity flattening the lava as it seeped. The model also showed a bulge developing that prevented the lava from spreading further, allowing for the buildup of the steep sides before the lava flattened out.

© 2025 Science X Network