Seisms in Venus?
UN/DICYT “Despite not being able to observe the surface directly due to its dense atmosphere, there is a region called Alpha with high fracturing with faults and folds (an area of approximately 700,000 square km and similar to the size of Texas) that evidence some type of seismic activity,” said Tovar, Cofounder and Codirector of the UNal Planetary Geology and Astrobiology Research Group (TITAN, for its Spanish acronym).
According to Tovar they have identified 1,194 volcanic centers with diameters exceeding 20 kms (12.4 miles) and 167 volcanos with diameters in excess of 100 kms (62 miles). In fact according to information provided by the European Space Agency’s (ESA) Venus Express space probe which orbited the planet until January of last year, the atmospheric concentration of sulphur dioxide has great variability and its cause could be current volcanic activity.
“It is not the same having an eruption with an air column as on Earth, where the flow depends of the magma composition and may be fluid or not depending on the viscosity as compared to underwater eruptions where the water pressure is very large. The pressure of the ocean may be compared to the air column pressure on Venus,” said Tovar.
When studying Venus they assume that due to its composition and mass distribution its interior should be similar to Earth; however it seems this is not the case. The way Venus releases heat from its interior, its atmospheric pressure as well as its global temperature are very different, which makes surface processes vary with respect to what are considered typical conditions on Earth.
Although they have yet to determine if there are active volcanos they do know Venus had them in the past as evidenced by surface reflectivity radar imagery showing lava flows.
In other words, “If brighter or more obscure areas provide us an indication of the topography and terrain, this may be a signal of lava flows on the surface,” he said during a recent TITAN organized conference cycle.
A planet with very dry rocks and no water
Venus does not have water and this is one of the most interesting features of its surface and its lithosphere in general. Rocks are ultra-dry and very different from those on Earth. “In general terms if we have to choose the planet most similar to Earth, it would be Venus (in size) but in reality, geologically speaking they have very little in common,” said Tovar.
The interesting question about Venus is if in its initial stages, could it have been habitable? Or did it ever have water? However these concerns have not been answered because it has not been studied that much.
In any case, technology is being developed to withstand the temperature of Venus (462 °C [864º F]) with the purpose of installing seismometers and understand its behavior and provide clues on planet formation.
“When there are craters it means there are not any active processes, while when the surface is smooth evidences recent geological activity,” he said.
As all planetary geology research, Tovar’s study is a comparative work where he hopes to understand how volcanos work on Earth or on Venus, as this would help comprehend how these rare formations have come to be such as the Ol Doinyo Lengai volcano in Tanzania which has very low-temperature eruptions.