Properties of New Flows Indicate that Martian Gullies Form via CO2 Frost‐Fluidization Processes

Abstract Martian gully landforms are widely seen as evidence of liquid water, often attributed to snowmelt during high‐obliquity periods within the last few million years. However, widespread present‐day flows within existing gullies are caused by CO2 frost, presenting an alternative formation mecha...

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Main Authors: Colin M. Dundas, Susan J. Conway, Kelly Pasquon, Axel Noblet, Lonneke Roelofs
Format: Article
Language:English
Published: Wiley 2025-05-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1029/2024GL112434
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author Colin M. Dundas
Susan J. Conway
Kelly Pasquon
Axel Noblet
Lonneke Roelofs
author_facet Colin M. Dundas
Susan J. Conway
Kelly Pasquon
Axel Noblet
Lonneke Roelofs
author_sort Colin M. Dundas
collection DOAJ
description Abstract Martian gully landforms are widely seen as evidence of liquid water, often attributed to snowmelt during high‐obliquity periods within the last few million years. However, widespread present‐day flows within existing gullies are caused by CO2 frost, presenting an alternative formation mechanism. Entrained frost vapourizes to fluidize flows, allowing them to behave similarly to wet debris flows on Earth. The slopes where present‐day flows erode and deposit provide insights into the landforms that many such flows could create. The shallowest slopes eroded by the flows are similar to slopes at existing channel mouths, and the most mobile flows reach final slopes similar to the outer reaches of existing gully aprons. This is consistent with formation of gullies entirely by CO2 frost‐driven flows, assuming their intensity and frequency varies in space and time. Geologically recent snowmelt cannot be ruled out, but is not required to explain the observed gully morphology.
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spelling doaj-art-e5474177606940ee9377fbe8e36147012025-08-20T03:21:32ZengWileyGeophysical Research Letters0094-82761944-80072025-05-01529n/an/a10.1029/2024GL112434Properties of New Flows Indicate that Martian Gullies Form via CO2 Frost‐Fluidization ProcessesColin M. Dundas0Susan J. Conway1Kelly Pasquon2Axel Noblet3Lonneke Roelofs4U.S. Geological Survey Astrogeology Science Center Flagstaff AZ USANantes Université—Université d'Angers—Le Mans Université CNRS UMR 6112 Laboratoire de Planétologie et Géosciences Nantes FranceNantes Université—Université d'Angers—Le Mans Université CNRS UMR 6112 Laboratoire de Planétologie et Géosciences Nantes FranceNantes Université—Université d'Angers—Le Mans Université CNRS UMR 6112 Laboratoire de Planétologie et Géosciences Nantes FranceDepartment of Physical Geography Faculty of Geosciences Utrecht University Utrecht The NetherlandsAbstract Martian gully landforms are widely seen as evidence of liquid water, often attributed to snowmelt during high‐obliquity periods within the last few million years. However, widespread present‐day flows within existing gullies are caused by CO2 frost, presenting an alternative formation mechanism. Entrained frost vapourizes to fluidize flows, allowing them to behave similarly to wet debris flows on Earth. The slopes where present‐day flows erode and deposit provide insights into the landforms that many such flows could create. The shallowest slopes eroded by the flows are similar to slopes at existing channel mouths, and the most mobile flows reach final slopes similar to the outer reaches of existing gully aprons. This is consistent with formation of gullies entirely by CO2 frost‐driven flows, assuming their intensity and frequency varies in space and time. Geologically recent snowmelt cannot be ruled out, but is not required to explain the observed gully morphology.https://doi.org/10.1029/2024GL112434MarsCO2 frostgulliesclimategeomorphologyliquid water
spellingShingle Colin M. Dundas
Susan J. Conway
Kelly Pasquon
Axel Noblet
Lonneke Roelofs
Properties of New Flows Indicate that Martian Gullies Form via CO2 Frost‐Fluidization Processes
Geophysical Research Letters
Mars
CO2 frost
gullies
climate
geomorphology
liquid water
title Properties of New Flows Indicate that Martian Gullies Form via CO2 Frost‐Fluidization Processes
title_full Properties of New Flows Indicate that Martian Gullies Form via CO2 Frost‐Fluidization Processes
title_fullStr Properties of New Flows Indicate that Martian Gullies Form via CO2 Frost‐Fluidization Processes
title_full_unstemmed Properties of New Flows Indicate that Martian Gullies Form via CO2 Frost‐Fluidization Processes
title_short Properties of New Flows Indicate that Martian Gullies Form via CO2 Frost‐Fluidization Processes
title_sort properties of new flows indicate that martian gullies form via co2 frost fluidization processes
topic Mars
CO2 frost
gullies
climate
geomorphology
liquid water
url https://doi.org/10.1029/2024GL112434
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