Geologists have found that on Venus there are a few dozen crowns, which was most recently active. This is the conclusion they came to by comparing the simulation results with real images of the volcanic structures. Today it is one of the best evidence that the planet is still happen the geological processes. Article published in the journal Nature Geoscience.
The surface of Venus is much younger than the surface of Mars or mercury. Scientists explain this by the fact that about half a billion years ago, increased volcanic activity, causing many of the old details of the relief were filled in with lava. In favor of the fact that on the planet today can continue geological processes, say crowns — unique round education with lots of cracks and faults discovered by astronomers three decades ago. They are formed when a jet of hot material deep within the planet rises through the layer of the mantle and the crust. However, for a long time it was believed that the crowns on Venus appeared in the ancient and now inactive, however, new simulations showed that it is not.
Anna Gulker (Anna J. P. Gülcher) at ETH Zurich together with colleagues have constructed a three-dimensional model of how the crowns are formed on Venus. She showed that the interaction of the lithosphere of Venus and mantle plumes leads to four main results: the appearance of lithospheric drops (when a part of the upper shell sinks into the hot mantle), a transient subduction (where one layer of crust sinks beneath another), embedded plumes (when mantle plume partially penetrates the lithosphere, but does not update the surface) and the plume-like underplating (when the plume reaches the lithosphere and spreads under it).
The first three scenarios led to the formation of circular formations, surrounded by a raised ring. In a similar way the rims look on Venus. A typical time evolution of such structures, according to the simulation, is only from 20 to 55 million years. Thus, according to the authors, different in shape, the crowns can not only reflect the different styles of interactions between mantle plumes and lithosphere, but also the different stages of evolution.
Comparison photographs of the surface of the planet with the simulation results showed that on Venus there are at least 37 active crowns, including the largest on the planet, the crown of Artemis with a diameter of 2,600 kilometers. Some crowns such as crown Arouri, are in the later stages of evolution and under these mantle plumes are already “asleep”, while the crowns as Amarati, might still be active.
The work of scientists supports the fact that Venus can still go geological processes. Active crowns grouped in several places, indicating that most “hot” areas of the planet, which gives an idea of its mineral resources. The results obtained by scientists can help to identify the most interesting areas for missions such as EnVision, which is scheduled for 2032.
Venus is not the only geologically active celestial body in the Solar system, other than Earth. Recently, astronomers found a network of young ridges on the visible side of the moon, which, in their opinion, evidence of ongoing tectonic processes. Furthermore, last year scientists managed to capture on Mars first earthquake, which allowed us to recognize the planet seismologically active.