These images are maps of the surface of Mars, showing where the volcanos are located.
Click on image for full size
Image from: NASA
An Overview of Martian Tectonism
Unlike Earth, there is no plate tectonics on Mars. The Martian surface does not seem to have changed or moved in billions of years. The evidence for this fact can be found in two ways.
- 1.) An examination of the surface of Mars shows cratering at all latitudes and longitudes. Craters are wiped out when the surface of a planet moves. Since cratering stopped soon after the solar system formed, about 4 billion years ago, a surface which still shows evidence of that catering has not changed in a very long time.
2.) Mars has several very
large volcanos. When the surface of a planet moves, volcanos are moved aside as well. They are worn down, and eventually
subducted below the surface. New volcanos arise to take the place of the ones which have been swept away. The Martian volcanoes became as large as they are because there was no plate tectonics to recycle the surface on which they were built.
The size of the volcanos also suggests that over its history, Mars has built a thick lithosphere, thick enough to support these very large volcanoes without allowing them to sink. A thick lithosphere would supress the motions of plates over a surface, even though the interior of the planet was warm enough for churning motions on the inside. Why would Mars, and not the Earth, have a thick lithosphere?
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:
The largest volcano in the solar system is Olympus Mons, shown in the image to the left. Olympus Mons is a Martian shield volcano. The altitude of Olympus Mons is three times the altitude of the largest
...more
During the Mars Pathfinder Rover's exploration of the Martian surface, it traversed what scientists now call the "Mermaid Dune", covered with soils. The soil on top of Mermaid Dune seemed to have a dark
...more
On this map of Mars, the lightly cratered Tharsis Ridge is shown, as well as the heavily cratered Martian highlands (near the bottom of the picture), and Valles Marineris to the right. The volcanoes are
...more
The unusual global geography of Mars helps to explain the fact that water has been drawn from the southern hemisphere to the northern hemisphere of the planet through all of Martian history (that is, from
...moreThe Martian geography is one of high altitudes at high southern latitudes and low altitudes at low latitudes. The ground is less frozen at low latitudes because it is warmer and water can evaporate. Thus,
...more
Separate from the Martian outflow channels, or the river valley networks, are large Martian lakes (600 km, or ~1000 miles across) which exhibit evidence of a periodic and catastrophic release of water
...more
This is an image of fog in a Martian canyon. The presence of fog provides evidence of water, and a water cycle on Mars. More fog has been seen in images returned by Mars Global Surveyor of the south polar
...more
The Martian climate is more influenced by the shape of the Martian orbit than the climate of the Earth is influenced by the shape of the Earth's orbit. The orbit of Mars is more elliptical than that of
...more
