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Basal melting of snow on early Mars: A possible origin of some valley networks
Author(s) -
Carr Michael H.,
Head James W.
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl018575
Subject(s) - mars exploration program , weathering , snowpack , snow , atmosphere (unit) , geology , liquid water , earth science , erosion , aeolian processes , regolith , astrobiology , geomorphology , environmental science , atmospheric sciences , hydrology (agriculture) , meteorology , geography , physics , geotechnical engineering
Valley networks appear to be cut by liquid water, yet simulations suggest that early Mars could not have been warmed enough by a CO 2 ‐H 2 O greenhouse to permit rainfall. The vulnerability of an early atmosphere to impact erosion, the likely rapid scavenging of CO 2 from the atmosphere by weathering, and the lack of detection of weathering products all support a cold early Mars. We explore the hypothesis that valley networks could have formed as a result of basal melting of thick snow and ice deposits. Depending on the heat flow, an early snowpack a few hundred meters to a few kilometers thick could undergo basal melting, providing water to cut valley networks.