UCLA Planetary Geologist An Yin thinks that Mars may have tectonic activity
I quoted an article about Yin's ideas (from early last year) a few days ago in another thread. However, I just say that UT and other sites posted news about him a couple days ago and I was wondering what anyone who has read his papers or knows about planetary geology thinks of his ideas.
from January 3, 2011
He identifies certain structures in various photos, and he goes on to say other items such as shifting drainage channels indicate movement, Valles Marineris is widely thought to be a tectonic feature, a line of volcanoes may indicate crustal motion over a hot spot and magnetic striping in some areas all indicate tectonic motion.A patch of land near the huge Martian volcano Olympus Mons may bear evidence of recent plate tectonic activity on the Red Planet, new research suggests.
The many ridges and scarps on the rumpled apron of land north and west of Olympus Mons are likely signs of tectonic thrusting, according to the study. And this activity could be very recent — within the last 250,000 years or so.
From August 17, 2012
Iv'e read that most suggest that Mars both has no magnetosphere and isn't tectonic because it's interior cooled, but isn't tectonics the major mechanism for moving heat out of the core? If so, then how does it cool off. Could it be via volcanoes alone? And how cool would the core be?“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.”
I'm wondering if it's a matter of temperature or a matter of circulation. Could the circulation have been fatally disrupted by the proposed impact that created the proposed Borealis Basin and the Martian Dichotomy? Or could an ancient slab have subducted down towards the core (as happens on earth) but due to the smaller size of the core and distance from the crust, could it have projected into or cooled one section of the liquid core (if it exists) and have stopped the a global circulation by stopping convection but without substantially cooling the entire core?