Since the launch of Mariner 9 in 1071 we have been getting better and better images and information about Mars, from improved satellite imagery, radar and ground sampling from the amazing Mars rovers.
We now know that both water and carbon dioxide ice exist on Mars. Polar ice caps, substantial ground and surface ice including glacier like forms (often referred to as GLFs in the relevant scientific literature) are all found on Mars. As a glaciologist working on debris-covered glaciers the GLFs are particularly interesting. Basically, these are things that, from the imagery, look very similar to glaciers on earth from satellite imagery, they show gravitational flow features and moraine loops and so on. However, the understanding of the flow and behaviour of GLFs is less clear than their existence. For one thing, there are crucial differences between the conditions on Earth and Mars (from Hubbard et al., 2014) that will affect glacier behaviour:
- Mars’ gravity, at ~3.7ms-2, is less than 40% of Earth’s.
- Mars’ surface temperature varies between -130 and +27°C, with a mean of about -60°C, so around 75°C lower than on Earth.
- Mars’ near-surface atmosphere has a partial pressure of H2O of ~1microbar, making the planet’s surface ~1000 times drier than Earth’s.
- Mars’ GLFs are covered in debris 1-10m thick, according to findings of the planetary radar project SHARAD and other flowing ice is expected to be an ice-debris mixture.
A GLF in Protonilus Mensae; Mars’ northern mid-latitudes (picture oriented north-up). Note the moraine-like structures at the GLF’s lower extremity (flow is di-rected to the S-E) and the crevasse patterns visible to-wards it’s mid-reaches.
Current research efforts seem to be focused on trying to model the flow behaviour of martian glaciers given the current and former conditions on Mars. Must be fascinating work and I always enjoy reading about the findings. Its also fun when my own modest contributions to our understanding of debris covered glaciers on Earth can be used to help other scientists understand the processes acting on Mars.
What prodded me to spend an hour of my Monday morning hunting out the latest publications on Martian glaciers was this video constructed from HiRISE imagery to reconstruct a flyover of parts of the surface of Mars – its quite amazing:
More things to look at for information on Martian glaciers:
Great post by Stephen Brough about ice on Mars: http://www.antarcticglaciers.org/glacial-geology/glaciers-mars/C and also have a look at his research website: https://glaciersonmars.com/
You can check out the amazing 3D (with glasses) HiRISE images from Mars here: http://www.uahirise.org/anaglyph/
Also, the Lunar and Planetary Laboratory of the University of Arizona, where the HiRISE project comes from, produces these cool one slide summaries of their research, which is a great idea that many more scientists could do: http://www.uahirise.org/epo/nuggets/
This freely available academic article describes in particular the GLFs: Hubbard, B., Souness, C., and Brough, S.: Glacier-like forms on Mars, The Cryosphere, 8, 2047-2061, doi:10.5194/tc-8-2047-2014, 2014.[pdf], and this one examines their former extents: Brough, S., Hubbard, B. and Hubbard, A.: Former extent of glacier-like forms on Mars, Icarus, 274, 37-49, 2016 [pdf].
These abstracts from the Sixth International Conference on Mars Polar Science and Exploration (2016) and the 48th and 47th Lunar and Planetary Science Conference (2017) are all freely downloadable (see here) and mostly easy to read:
Applying Knowledge from Terrestrial Debris-Covered Glaciers to Constrain the Evolution of Martian Debris-Covered Ice
M. R. Koutnik, A. V. Pathare, C. Todd, E. Waddington, J. E. Christian
Sixth International Conference on Mars Polar Science and Exploration (2016), Abstract #6065
Physical Properties of Supraglacial Debris on Mars
D. M. H. Baker, L. M. Carter
Sixth International Conference on Mars Polar Science and Exploration (2016), Abstract #6087
Applications of Ice-Flow Models to Mars
M. R. Koutnik, A. V. Pathare, E. D. Waddington, C. E. Todd, J. E. Christian
48th Lunar and Planetary Science Conference (2017), Abstract #2188
Hot Mess, Cold Glaciers: Characterizing Ridges on Martian and Terrestrial Debris-Covered Glaciers Using Observations and Flow Modelling
C. M. Stuurman, J. W. Holt, J. S. Levy, E. I. Petersen
48th Lunar and Planetary Science Conference (2017), Abstract #2740
Ice-Cored Moraines May Preserve Climate History in Their Stratigraphy: A Mars Analog Study at Galena Creek Rock Glacier
E. I. Petersen, J. W. Holt, J. S. Levy, C. S. Stuurman
48th Lunar and Planetary Science Conference (2017), Abstract #2966
New Constraints on Surface Debris Layer Composition for Martian Mid-Latitude Glaciers from SHARAD and HiRISE
E. I. Petersen, J. W. Holt, J. S. Levy, T. A. Goudge
48th Lunar and Planetary Science Conference (2017), Abstract #2767