A view on the glacio-geological history of Mars, from flow to form

The geological and hydrological history of Mars are marked by a long-term climate change caused by the irreversible loss of the martian atmosphere to space, which took the red planet from conditions favorable for the presence of surface liquid water around 3.5-4 Byr years ago to the current global hyperarid cryosphere. Despite this, Mars has a rich surface geomorphology intimately linked to the action of water, characterized by hundreds of valleys, ancient deltas and alluvial fans, massive mega-canyons, large buried ice deposits, and debris-covered glaciers. Mars, a planet characterized by a lower surface gravity, lower solar insolation and a thinner atmosphere, likely experienced cold and hyperarid surface conditions throughout most of its history. However, clear fingerprints of the erosional action of glaciers and ice sheets on Mars are conspicuously missing (with few and far exceptions), even when all factors from the water budget of Mars to its reduced surface temperature would suggest that large ice sheets with erosional potential most likely existed. This talk will explore the apparent lack of glacial landforms on Mars from the perspective of ice dynamics and erosion. By taking into account the effect of a lower surface gravity and colder and drier climates, I will show that the erosional potential of glaciers and ice sheets, as well as the type of landforms produced, may significantly differ at the low surface gravity of Mars. Physical depictions of glacial erosion will be complimented with field observations of cold, thin ice caps on the Canadian Arctic Archipelago, which may capture more accurately the unique dynamics of martian glaciers. In this talk I will step through numerical models, fieldwork observations, and geomorphological studies to show that the geological fingerprint of martian glaciations may be significantly different from the terrestrial record, more closely linked to glaciofluvial drainage than to erosion due to glacial sliding. Understanding the impact of glaciations on Mars' geological record is important to recognize former water environments and identify places where life, if it ever existed, could have developed or survived throughout the red planet's history.