AbstractMars‟ mid-latitudes host a range of apparently flow-related landforms that strongly resemble terrestrial glaciers. Such ‘glacier-like forms’ (GLFs) are strikingly similar to alpine valley glaciers found on Earth. These martian GLFs are believed to be composed of massive water ice but little is known about how they formed, how they evolve, and how they interact with the martian surface. This thesis presents various studies of Mars‟ mid-latitude GLFs that were designed to address some of these issues. New observations and new results were obtained using survey and mapping techniques.
The findings presented in this thesis suggest that GLFs, observed ubiquitously in Mars’ mid-latitudes, are all composed of a similar material and were formed in a similar way, most likely under Earth-like ‘mass-balance’ conditions whereby ice accumulated at altitude and subsequently flowed, under its own weight, downhill and into an ablation zone where GLFs experienced net mass loss. It is likely these conditions existed on Mars during a past martian ice age.
From their geographical distribution (relative to latitude, elevation and relief) it would appear that those GLFs that remain on Mars today are relict deposits that have survived where local conditions impair ablation, and that these residual GLFs appear currently to flow under the influence of local relief and gravity. From the examination of crevasse patterns it appears that this flow occurs under an englacial strain regime similar to that which commonly defines spatial flow patterns in terrestrial glaciers. This thesis also observes and identifies various small-scale features and textures that suggest that the evolution and subsequent flow of GLFs has been (or may currently be) sensitive to many environmental factors common on Earth, such as the agency of liquid water. This suggests that GLFs (and possibly other associated ice masses) may have been significant movers and shapers of Mars‟ surface sediments and structures, contributing widely to the evolution of Mars‟ present-day surface.
|Date of Award
|24 Apr 2013
|Natural Environment Research Council
|Bryn Hubbard (Supervisor) & Duncan Joseph Quincey (Supervisor)