The record of warm-based glaciation on ancient Mars

• Main Authors: Grau Galofre, Anna, Whipple, Kelin, Christensen, Philip, Conway, Susan
• Other Authors: Laboratoire de Planétologie et Géosciences UMR_C 6112 (LPG), Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology; [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology; Christensen; Conway; Nunavut; Ice Sheet
• Online Access: https://hal.science/hal-04290900; https://doi.org/10.5194/epsc2022-442

International audience THE RECORD OF WARM-BASED GLACIATION ON ANCIENT MARS. A. Grau Galofre. 1,2 , K. X. Whipple 2 , P. R. Christensen 2 , S. J. Conway 1 1 Laboratoire de Planétologie et Géosciences CNRS UMR 6112, Nantes Université, France ([e-mail]) 2 School of Earth and Space Exploration, Arizona State University, Tempe, AZ, US Introduction: The missing evidence for large-scale glacial scouring landscapes on Mars has led to the belief that past martian glaciations were frozen to the ground [1,2]. Indeed, whereas warm-based ice masses (with presence of basal meltwater), produce some of the most striking erosional patterns on Earth (Figure 1, panels 2 and 3), these same morphologies are notoriously rare on Mars [1,2]. Two issues arise with this perspective. First, Mars’ climate in the Noachian-Hesperian (~3.8-3.5 Ga) allowed for surface liquid water [3,4]. The transition from this early climate to the current day global cryosphere with no presence of basal meltwater under ice masses poses a problematic transient [1]. Second, the presence of eskers in the Dorsa Argentea formation (DAf) [5,6,7], and in the mid-latitudes [8] shows that basal melting occurred in spite of the lack of glacial sliding. Our work hypothesizes that the fingerprints of Martian warm-based glaciation are the remnants of the ice sheet drainage system (channel and eskers), instead of the scoured regions associated with terrestrial Quaternary glaciation (Figure 1). Figure 1. Fingerprints of terrestrial warm-based glaciation. (1) Subglacial channels (Nunavut). (2) Mega-scale lineations (Québec). (2) Scouring marks and striae (Finland). (4) Esker (66.1N, 104.50W). To make progress, we use models of terrestrial glacial hydrology to interrogate how the Martian surface gravity modifies glacial drainage, ice sliding velocity, and glacial erosion rates. Taking as reference the geometry of the ancient southern circumpolar ice sheet (ASCIS) associated with the DAf [6], we model the behavior of identical ice sheets on Mars and ...