3D morphometry of valley networks on Mars from HRSC/MEX DEMs: Implications for climatic evolution through time

Research areas:
Year:
2013
Authors:
Journal:
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
Volume:
118
Number:
9
Pages:
1873-1894
Month:
September
ISSN:
2169-9097
Abstract:
Martian valley networks have been identified mainly in the Noachian
heavily cratered uplands. Eight dense branching valley networks were
studied in Noachian terrains of Huygens, Newcomb and Kepler craters,
south Tyrrhena Terra, and Thaumasia, in Hesperian terrains of Echus
Plateau and west Eberswalde craters, and in Amazonian terrains of Alba
Patera, using images and digital elevation models from the Mars Express
High Resolution Stereo Camera to determine 2D and 3D morphometric
parameters. Extracted geomorphic parameters show similar geometry to
terrestrial valleys: drainage densities, organization from bifurcation
ratios and lengths ratios, Hack exponent consistent with terrestrial
values of similar to 0.6, and progressive deepening of valleys with
increasing Strahler order. In addition, statistics on valley depths
indicate a deeper incision of Noachian valleys compared to younger
post-Noachian valleys (100 m for
Noachian ones), showing a strong difference in fluvial erosion. These
characteristics show that dense Martian valley networks formed by
overland flows in relation to a global atmospheric water cycle in
Noachian epoch and confirm that the later stages of activity may be
related to shorter duration of activity, distinct climatic conditions,
and/or regional processes, or conditions.