Mystery Unveiled: The Enigmatic Origin of Venus' Flat-topped Volcanoes
In a groundbreaking study published in the Journal of Geophysical Research: Planets earlier this month, scientists have shed light on the formation of Venus' distinctive volcanic features known as "pancake domes." These flat-topped, steep-sided structures, typically several tens of kilometers in diameter and about 1 km high, are remarkably circular in shape.
The research, led by Dr. Sarah Stewart, focused on Narina Tholus, a particularly enormous dome on Venus that stretches nearly 145 kilometers across. The team's findings suggest that the flexibility of Venus' crust plays a significant role in the domes' formation.
The study reveals that the thick, highly viscous lava extrusion is a key factor in the creation of pancake domes. The lava is thought to be richer in silica compared to typical basaltic lava on Venus, which makes it much more viscous and less fluid. This viscous lava extrudes from a central vent and spreads out only a short distance before solidifying, forming the characteristic flat, broad structures.
However, the lava alone does not explain the domes' unusual shape. The research shows that the flexure of the crust influences the shape of the domes, making their tops flatter and their sides steeper in the presence of more flexure. This is due to the limited flexibility and strength of the crust, which constrains the lava flow and prevents extensive spreading. Instead, the highly viscous lava extruded forms broad, thick, pancake-shaped domes.
The thick, relatively inflexible lithosphere of Venus, estimated to be around 100-300 km thick, limits tectonic plate movement but still allows some degree of flexure or bending under volcanic loads. This flexure, in turn, contributes to the formation of the unique flat-topped domes. Unlike Earth, Venus does not have active plate tectonics to recycle the crust rapidly, which means volcanic activity builds up these pancake domes in situ, without significant disruption from tectonic shifts.
The team's model, while based on just one dome, reproduces the crustal bulges spotted around some domes in previous studies and simulates lava flowing over a bendy lithosphere to form flat tops with steep sides, similar to Venus' pancake domes. The ultra-dense lava, more than twice the density of water and over a trillion times as viscous as ketchup, matches both the dome shape and the surrounding deformation.
Upcoming missions like NASA's VERITAS or DAVINCI will provide better topographic data to test the theory across more of Venus' thousands of volcanic features. A better understanding of these features could yield more insights into the formation of Venus, often referred to as Earth's evil twin. The planetary evolution of Venus split off from the timeline that made our world wet, verdant, and rife with life. Despite its inhospitable surface today, studying Venus may provide valuable insights into the early history of our solar system.
- The groundbreaking study published in the Journal of Geophysical Research: Planets revealed that the unique pancake domes on Venus, like those found on Narina Tholus, are formed through a combination of highly viscous lava extrusion and the flexure of Venus' crust.
- In the future, space missions like NASA's VERITAS or DAVINCI could provide valuable topographic data to test the theory about the formation of Venus' pancake domes across a wider range of the planet's volcanic features.
- As Gizmodo reports, understanding the formation of Venus' pancake domes could offer insights into the planetary evolution of Venus, often referred to as Earth's evil twin, and potentially provide valuable insights into the early history of our solar system.
- Meanwhile, in the realm of health-and-wellness and environmental-science, the study could also have implications for understanding more about the properties of highly viscous substances and their behavior under specific conditions, a finding that could have applications in various technological and industrial sectors.
