The HiRISE camera onboard the Mars Reconnaissance Orbiter captures high resolution satellite images of up to 25cm per pixel. To supplement our understanding of particle motion, I chose an image of an impact crater with many talus slopes lining its walls and selected boulders 2m or larger to analyze patterns in point densities relating to upslope topography. The results seem to suggest that when the talus slopes become more topographically distinct, the boulders below them deposit in clusters between subsequent talus slopes. This clustering is not as obvious below potions of the crater that are more flat. I hope to conduct future work to analyze the boulders’ velocities at the base of impact craters and compare their distances travelled to those expected on Earth using equations I modified from Furbish et al. (2020).
8 thoughts on “Topography and Depositional Patterns of Rockfall in a Martian Impact Crater”
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Hi!
My thesis work revolves around providing a probabilistic, rarefied mechanical theory behind particle motion down non-linear hillslopes (i.e. surfaces with varying topography). With these HiRISE images of Mars readily available to the public, I thought it would be interesting to apply what I have learned in this class to analyses of rockfall on Mars. After all, gravity on Mars is 1/3 of Earth, so we would expect particle motion to be an interesting phenomenon on Mars; I hope to address this further in my thesis work. In addition to my point density analysis, I also chose to conduct an interesting GIS application called geomorphon classification. The orthoimage I used is at such a high resolution that it is easy to image the topography of the image, but this landform classification provides another unique way of viewing the image.
Thanks for taking the time to look at my poster!
Would you expect that the distances particles travel on Mars would be more or less than on Earth due to the differences on gravity? And would this likely change the distribution of landforms on which boulders are deposited?
Particles would most likely travel a lot further, so this it what part of my thesis work hopes to determine. In regards to your second question, I’m not entirely sure, but if the mechanisms of particle motion on Mars are similar to those on Earth, since they might travel further, they may come to rest on flatter surfaces, rather than stop further up on the slope of the crater wall.
Incidentally, one of my final projects in another class was a piece on applications of GIS beyond Earth. I talked to Valentin Bickel who recently published a piece on lunar rockfalls that you may have come across in you research. He used computer vision to create a global map of rockfalls on the moon. Do you think similar techniques (computer vision) could also be applied on Mars?
Yeah, and it would definitely make things go faster. In fact, I read one of Bickel’s papers where he used machine learning to detect rockfall on Mars using the tracks the rocks leave behind. Other papers have done similar things, and I considered using one professor’s code to do the same, but it got a bit complicated.
Erika– love how this turned out. Would be interested to chat with you sometime about the work you did in GRASS, classifying the geomorphology of the crater. Do you still plan to look at elevation profiles within the crater? Looking forward to seeing how you continue to develop this project!
Yes, I’ll email you and we can find a time to chat. For this project, I didn’t have enough time to also incorporate the elevation transects, but yes, I plan on using those to collect the elevation at the base of the crater to then calculate the velocity of particles when they are deposited on a hill. I plan to do that particular analysis on another HiRISE image though.
Really interesting, Erika–and really well done as a poster, clearly presented. I’m curious about geomorphon. It looks like a moving window analysis of observed directionality of particles? Is it comparing an observed against null hypothesis distributions, or is is providing a metric of observed particle distributions?
I wonder why there are more boulders on ridgetops than expected, and what the finding regarding rocks deviating from the fall line might tell us about such processes on earth. This is a controlled comparison, in that we know the mass of Mars and its gravitational constant, etc. I suppose that contexts with similar slope angles and and landforms could then be compared. Or is it the case that the landforms are different because of the differences in mass/gravity, making comparison difficult?
Looks like you have the heart of a chapter for your thesis–good job!