Unveiling Venus: How Pancake Domes Formed from Unique Volcanic Activity

Unveiling Venus: How Pancake Domes Formed from Unique Volcanic Activity

Venus, often dubbed Earth's evil twin, harbors some of the most enigmatic geological formations in our solar system. Among these are the pancake domes—massive, circular volcanic structures that appear strikingly similar to giant flapjacks lying on the planet's scorched surface. For years, scientists have theorized that these unusual formations emerged from the slow drip of thick, viscous lava. Recent research, however, has illuminated additional factors influencing their creation.

A recent study focused on one of the largest known pancake domes on Venus, named Narina Tholus, which boasts a diameter of nearly 90 miles (145 kilometers). By utilizing radar data from NASA’s Magellan mission, which collected detailed information in the 1990s, researchers constructed a sophisticated digital model of the dome. This model enabled them to explore the effects of various lava properties and surface behaviors on the dome's shape.

Findings from their simulations revealed that lava alone could not fully account for Narina Tholus's distinctive flattened summit and sharply sloped edges. Instead, researchers discovered the crucial role of crustal flexure—the ability of the lithosphere, or the outer shell of Venus, to bend under pressure. Their analysis indicated that higher levels of flexure lead to flatter dome tops and steeper sides.

• Crustal Behavior: The deformation of the crust limits how far lava can spread, resulting in a characteristic pancake dome shape.
• Unique Lava Properties: The study revealed that only specific types of lava were effective in modeling these structures. The simulations demonstrated that ultra-dense, highly viscous lava—approximately a trillion times thicker than ketchup and twice as dense as water—was needed.
• Lava Flow Dynamics: Such a dense lava would flow exceptionally slowly, possibly taking hundreds of thousands of Earth years to reach its final form. This slow movement is essential in creating the observed crustal bulges surrounding the domes.

The behavior of the lava upon encountering a pliable surface is what produces the pancake-like shapes found across Venus. This research marks a notable advance in understanding Venus's volcanic activity and history, as it correlates both dense lava and a responsive lithosphere to produce these peculiar geological formations.

However, it is important to note that this study's conclusions are based on just one dome. Future missions, such as NASA’s VERITAS and DAVINCI, are expected to provide enhanced topographic data and geological insights from Venus's surface. These missions plan to examine thousands of other volcanic features to determine whether similar crust-lava interactions influence their formation as well.

If subsequently verified, these groundbreaking findings could significantly alter our understanding of Venus's evolution, shedding light on the reasons behind the stark divergence in development between Venus and Earth, despite their comparable size and composition.