The mid-latitudes of Mars host numerous ice-related landforms that bear many similarities to terrestrial ice masses. One particular landform has a strong resemblance to valley or debris-covered glaciers found on Earth and have subsequently become known as ‘glacier-like forms’ (GLFs). GLFs have detailed surface morphologies consistent with recent deposition and viscous deformation of ice, but there is still uncertainty regarding their formation, current and former volume, and dynamic evolution. Specifically, this thesis presents new observations and results that assess the current and former volume and dynamics of Mars’ mid-latitude GLFs. The findings presented in this thesis suggest that at the broadest level Mars’ midlatitudes appear to preserve a complex and spatially heterogeneous record of glaciation and that GLFs appear to be the manifestation of a more localised period of alpine glaciation. GLFs represent an active component of the near-surface water budget of Mars, locking away an estimated global equivalent water layer of between 3 ± 1 and 10 ± 3 mm. Evidence of recession and mass loss was identified in approximately one-third (n = 436) of the GLF population, suggesting that these landforms once contributed a larger volume of water to the near-surface water budget of Mars. Assessment of environmental and topographical controls over current ice volume and ice-mass loss revealed that their distribution and size is unlikely to be purely controlled by insolation forcing. Instead it is suggested that regional to local meteorological and topographical conditions also play an important role in GLF ice accumulation and/or preservation, with variation in physical environments providing microclimates favourable for accumulation and/or preservation of ice. The emerging picture shows that Mars’ GLFs appear to have been dynamically active, and that they have played an important role in altering the surface landscape of Mars through erosion, transport and deposition of material.
|Date of Award||2017|
|Supervisor||Bryn Hubbard (Supervisor) & Alun Hubbard (Supervisor)|
Current and former volume and dynamics of mid-latitude glacier-like forms on Mars
Brough, S. (Author). 2017
Student thesis: Doctoral Thesis › Doctor of Philosophy