Chapter 3 - Martian Gullies and Their Connection With the Martian Climate

Research areas:
Year:
2018
Keywords:
Carbon dioxide, GCM, Habitability, Landscape evolution, Liquid water, Martian gullies, Sublimation
Authors:
Publisher:
Elsevier
Editor:
Richard J. Soare and Susan J. Conway and Stephen M. Clifford
Pages:
87 - 119
ISBN:
978-0-12-813018-6
Abstract:
Since the discovery of gullies on Mars nearly two decades ago, their study has evolved significantly. Initially, they were hailed as evidence of active liquid water martian aquifers; were this assumption valid, the aquifers could represent a significant reservoir of liquid water. This conclusion was tempered by global data, revealing intriguing climatic signals interpreted to signify an episodic top-down melting scenario, indicating a more modest hydrosphere. Recently, authors have favored completely dry gully formation engendered by an exotic solid CO2 sublimation mechanism never before observed on any other planetary surface suggesting a desert planet. This chapter will not only review these end-member formation hypotheses but also will critically examine them in light of all currently available population-scale data and new climate simulations. We conclude that neither water nor CO2 can explain the observational data for martian gullies, but that water is consistent with more of the observational data.