There is no subduction of the crust of Venus (shown here).
Click on image for full size
The Venus Lithosphere
Like the Earth's lithosphere, the lithosphere of Venus is the not-so-rigid part of the crust of Venus which is cooler than the interior of Venus, somewhat like the film on top of a cup of hot cocoa. Unlike the Earth, the lithosphere of Venus may be too thick to move.
arth, the lithosphere can be pushed aside in response to the warmth of the Earth. The lithosphere then subducts, melts, and becomes part of the warm rising magma again. Thus on Earth, the recycling of the lithosphere keeps the lithosphere from becoming
The shape of the volcanoes suggests that in its history, Venus, like Mars, has built a thick lithosphere. A thick lithosphere supresses the
motions of plates over a surface, even though the interior of the planet is warm enough for churning motions which cause material to rise from the deep interior.
Why would Venus, and not the Earth, have a thick lithosphere? The answer is that unlike the Earth, the rocky material which comprises the lithosphere of Venus does not contain enough trapped water to allow the lithosphere to deform and subduct. Thus
the lithosphere cannot make way for hot, rising magma from the interior and instead stays in place and thickens by cooling gradually.
Nevertheless, on Venus, there may be mechanisms for the surface to turn over.
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, as well as books
on science education!
You might also be interested in:
How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more
Unlike Mars, it is not the size but the shape of the volcanoes which suggests that over its history Venus has built a thick lithosphere. The shape of the volcanoes suggests that there has been no slumping...more
The terrestrial planets formed by accretion of rocky material and volatiles out of the primitive solar nebula. As they finished forming, about 4 Billion Years ago, the surface continued to be bombarded...more
Like Mars, there is no plate tectonics on the surface of Venus. The surface of Venus does not *seem* to have changed or moved in billions of years. Unlike the case of Mars, however, careful examination...more
Alpha Regio and Ovda Regio are examples of what is known as a "Plateau Highland" of Venus. Among the volcanic features of Alpha Regio is Eve Mons. Unlike volcanic rises, plateau highlands have few volcanoes,...more
Aphrodite Terra, the Greek name for the goddess Venus, is about half the size of the African continent, and is to be found along Venus' equator. Aphrodite Terra is different from Ishtar Terra in that,...more
Beta Regio and Atla Regio are examples of what is known as a volcanic rise. Volcanic rises are broad, sloping highlands over 1000 km across. They are cut by deep troughs 100-200 km across. These troughs...more
Ishtar Terra is one of the Plateau Highlands of Venus, is found near the north pole, and is about the size of the continental United States. Ishtar Terra contains the four main mountain ranges of Venus...more