Top: Colour Peak gullies, Axel Heiberg. Middle: Gypsum Hill cold springs,  Axel Heiberg. Bottom:  Eureka retrogressive thaw slumps, Ellesmere Island.

An Investigation of Martian and Arctic Gullies:

The Role of Ground Ice and Salt-Saturated Ground Water 

in the Development of Terrestrial Analogues

Ph.D. Thesis Summary

Supervisor: Prof. Wayne H. Pollard (pollard@felix.geog.mcgill.ca)

The process of thermoerosion, combined with the distinct mechanics behavior of frozen soils, is known to alter the formation of gully weathering; yet only sparse and fragmented information is available on the subject.  Gullies are small, steep-sided channel, often with an alcove head scarp and a debris apron, caused by erosion due to the intermittent flow of water.  Although investigations have been limited thus far to temperate regions, gullying is also widespread under sub-freezing polar desert conditions. Indeed, evidence suggests that almost any concentrated flow may there give rise to a classic type of slope gully morphology.  Moreover, the minute amounts of water required to create such distinctive landforms may only involve very local melting of near-surface ground ice or more intriguingly perhaps, mineralized groundwater flow through unusual piping systems.  In all cases, as observed in the Canadian High Arctic, the resulting landforms make for unique and stunning sceneries.  The goal of the proposed research is to develop a better understanding of the on-slope processes that contribute, in cold environments, to gully development and deposition within the debris aprons, as well as the variations in their interactions.  This field-based study, supported by laboratory analysis and modelling, will examine various gully scale channels throughout Ellesmere and Axel Heiberg Islands that are directly related to some combination of perennial spring occurrences and episodic buried flows or seasonal runoff from melting snowpack and the degradation of ground ice. This study also intends to contribute valuable information concerning hydrological systems operating in the presence of permafrost and to assess the applicability of terrestrial gullies in the Arctic to reconstruct the geologic history of the relatively young and morphologically similar features recently reported on Mars at mid-to-high latitudes.