Research ArticlePLANETARY SCIENCE

Branching geometry of valley networks on Mars and Earth and its implications for early Martian climate

See allHide authors and affiliations

Science Advances  27 Jun 2018:
Vol. 4, no. 6, eaar6692
DOI: 10.1126/sciadv.aar6692

You are currently viewing the abstract.

View Full Text

Abstract

Mars’ surface bears the imprint of valley networks formed billions of years ago. Whether these networks were formed by groundwater sapping, ice melt, or fluvial runoff has been debated for decades. These different scenarios have profoundly different implications for Mars’ climatic history and thus for its habitability in the distant past. Recent studies on Earth revealed that valley networks in arid landscapes with more surface runoff branch at narrower angles, while in humid environments with more groundwater flow, branching angles are much wider. We find that valley networks on Mars generally tend to branch at narrow angles similar to those found in arid landscapes on Earth. This result supports the inference that Mars once had an active hydrologic cycle and that Mars’ valley networks were formed primarily by overland flow erosion, with groundwater seepage playing only a minor role.

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.

View Full Text