Caption: Valles Marineris NASA World Wind Map Mars Credit: NASA
Until now, Earth was thought to be the only planet with plate tectonics. But a huge “crack” in Mars’ surface — the massive Valles Marinaris — shows evidence of the movement of huge crustal plates beneath the planet’s surface, meaning Mars may be showing the early stages of plate tectonics. This discovery can perhaps also shed light on how the plate tectonics process began here on Earth.
Valles Marineris is no ordinary crack on the Martian surface. It is the longest and deepest system of canyons in the Solar System. Stretching nearly 2,500 miles, it is nine times longer than Earth’s Grand Canyon.
An Yin, a planetary geologist and UCLA professor of Earth and space sciences, analyzed satellite images from THEMIS (Thermal Emission Imaging System), on board the Mars Odyssey spacecraft, and from the HIRISE (High Resolution Imaging Science Experiment) camera on NASA’s Mars Reconnaissance Orbiter.
“When I studied the satellite images from Mars, many of the features looked very much like fault systems I have seen in the Himalayas and Tibet, and in California as well, including the geomorphology,” he said.
The two plates that Yin calls Valles Marineris North and Valles Marineris South are moving approximately 93 miles horizontally relative to each other. By comparison, California’s San Andreas Fault, which is similarly over the intersection of two plates, has moved about twice as much, because Earth is about twice the size of Mars.
Yin believes Mars has no more than two plates whereas Earth has seven major plates and dozens of smaller ones. As Yin puts it “Earth has a very broken ‘egg shell,’ so its surface has many plates; Mars’ is slightly broken and may be on the way to becoming very broken, except its pace is very slow due to its small size and, thus, less thermal energy to drive it. This may be the reason Mars has fewer plates than on Earth.”
Mars also has several long, straight chains of volcanoes, including three that make up the Tharsis Montes, three large shield volcanoes which includes Olympus Mons, the tallest mountain in the Solar System at 22 km high. These volcanic chains may have formed from the motion of a plate sitting over a “hot spot” in the Martian mantle, in the same way the Hawaiian Islands are thought to have formed here on Earth. Yin also identified a steep cliff similar to cliffs in California’s Death Valley, which are generated by a fault, as well as a very smooth and flat side of a canyon wall which Yin says is also strong evidence of tectonic activity.
Yin also suggests that the fault is shifting occasionally, and may even produce “Marsquakes” every now and again. “I think the fault is probably still active, but not every day. It wakes up every once in a while, over a very long duration — perhaps every million years or more,” he said.
It is not known how far beneath the surface the plates on Mars are located. Yin admits “I don’t quite understand why the plates are moving with such a large magnitude or what the rate of movement is; maybe Mars has a different form of plate tectonics,” Yin said. “The rate is much slower than on Earth.”
“Mars is at a primitive stage of plate tectonics,” Yin added. “It gives us a glimpse of how the early Earth may have looked and may help us understand how plate tectonics began on Earth.”
Yin’s study was published in the August issue of the journal Lithosphere and he also plans to publish a follow-up paper hoping to shed more light on plate tectonics on both Mars and Earth.
If Earth wouldn’t marginal for plate tectonics, it would mean a lot for extending habitability as we know it.
Incidentally the new knowledge that Mars may well have the same original water content in the mantle as Earth both support this and goes into defining the constraints of plate tectonics.
The observation of both a plate tectonic style rift valley and the typical hot spot behavior of moving plates are encouraging. They may define “the differential horizontal motion of plates”, which is the proposed key criteria in a relatively recent work that tries to systematize plate tectonics [HT: Metageologist.]
This criteria should be able to distinguish plate tectonics from “plume tectonics” such as what drives hot spots and is a completely different way of transferring heat out. Doing this, it appears [haven’t read the paper] that one find plate tectonic processes go way back in Earth history. I know from earlier works on zircons that they bear witness to the existence of plate boundary zones and overlying plates going back to perhaps ~ 4 Ga bp (billion years before present), IIRC. That is at least 0.5 – 0.7 Ga older than some text books.
This is of course an interesting aspect for habitability too.
Metageologist’s take:
“Evidence from geochemistry and metal deposits is also brought to bare to argue that plate tectonics was active for most of the Precambrian and may have been active from the dawn of earth’s history. Precambrian rocks are distinctive, but the fundamental mechanism that drives the modern earth affected them too.”
Now it appears a good idea would be to read both the criteria paper and the martian paper and see whether the latter is consistent with the former. [pulls up shirt arms and starts reading]
Mars is in a sense a rump version of Earth. It should not be surprising that it has tectonic activity. This is really due to mantle convection which moves lithosphere or plates on top. Water is sort of the lubricant which makes the plates slip, and it is evident that Mars had a water environment. The Curiosity Rover is parked in front of what look like alluvial fans, which suggest not just past water environments, but hydro activity coming from sedimentary layers in this crater.
LC
In a primitive or in a terminal stage of plate tectonics?
Thats precisely what I was thinking. Mars is going to cool much faster and hasn’t the water to lubricate grating plates. This is a fault is it shall remain for all eternity.
Plate tectonics as in an overlooked impact generated feature? The Valles Marineris and the chain of ancient volcano’s including Olympus Mons, Lascraeus Mons, Pavonis Mons and Arsia Mons lie almost directly antipodal to the humongous southern hemisphere impact crater known as Hellas Planitia. That impact would have sent shock waves completely through the planet which then would ‘focus’ on the side opposite…. especially if the progenitor was of a high density… say an asteroid with a FeNi core?
http://pubs.usgs.gov/imap/i2782/i2782_sh1.pdf
Am I the only one who see’s the connection?
P.S. Note that the Hellas Planitia crater is obround, indicating a high impact angle which might have ‘skewed’ the loci of antipodal resonances – effectively spreading the pattern and enhancing it’s effects over a wider area.
IIRC it has been proposed before. But the real large likely impactor is the one that created the norther Borealis basin. And it hasn’t any such antipodal feature.
More generally, it is pattern searching, no mechanism is proposed. Eg what effects would shock waves have, and how far would they travel: they are not _shock_ waves for very long as they dissipate their energy and slows down to regular seismic waves.
What about Venus? It has plate tectonics too!
It does not.
http://en.wikipedia.org/wiki/Plate_tectonics#Venus
JPL proposed a Phoenix-like seismology lander called InSight for the next Discovery class mission. Among them was a comet hopper and a Titan lake buoy. Wasn’t the agency supposed to announce a selection a month ago?
Judging from the abstract, the paper seems a very well-argued piece of work. However it only ”
begs the question of why such a structure, typically associated with plate tectonics on Earth, has developed on Mars.” The comments from the author, which is what most press (including here) have run with, seem a lot less sensible and justified.
The plates of earth have discontinuities all around them and move 1000’s of kilometres relative to each other. I don’t see how a single fault with 100 kms of movement can be called plate tectonics. Also the phrase “It is not known how far beneath the surface the plates on Mars are located” doesn’t make sense – the plate *are* the surface. As an number of you have also suggested, the early earth was much hotter than current earth, meaning that smaller colder Mars is unlikely to give a glimpse of early earth plate tectonics.
None of the press on this has been at all critical, despite all these issues with what Prof. Yin is saying. Is this silly season science reporting?
@metageologist
What a pity that the Curiosity Rover’s power supply didn’t come with an external socket to keep on driving. That not being possible use sessile stance for other technology. We could have sent a follow up power supply. It would have been a very small vehicle. Very cost effective. Double sided solar panelled and wheels, ideal for steep territory, self correcting if toppled. With an autonomous rechargeable or one use supply check out natural cavernous or cave system/layers/tectonics. An easy low cost way to start terraforming Mars is to seed its water carrying polar caps with polar photosynthetic bacteria from Earth. Any geological thermal sources cropping up on the surface of Mars from its newly described tectonic geology could be used as power sources for all introduced Earth life forms so try and combine first settlements with those of water source locations.
Considering all the below comments, I am surprised that one important aspect has not be touched upon. As many of us know, the magnetic field of mars is sporadic and it has no global field. The reason for this has been given as the absence of a liquid core which can produce the field. In Earth, our seismic plates rest on this liquid core and is the reason for the seismic activity. Following the same train of thought, something is amiss in this discussion. Can someone connect the dots please??