Water Flows on Mars: a laboratory, field and image-based approach

Abstract

The loan of three differential Leica System 1200 GPS from NERC GEF was used to facilitate the collection of long profile and cross profile data of gullies formed by ephemeral water flow in La Gomera, Canary Islands, Spain. This data provided long profile data to compare to other gully systems with different formation processes on Earth and to gullies on Mars where the formation process is under current debate. Three gullies were surveyed and over 1500 points collected. The majority of the points had better accuracy than the inherent terrain roughness (10-25cm) in both the vertical and horizontal. The profile data suggest gullies in La Gomera are more similar to gullies on Mars than debris flow gullies on Earth. Isopach maps were generated from the data to assess the effect of channel slope on the volume of erosion and deposition. Analysis of the isopach data reveals a more complex relationship between erosion and slope than that revealed by similar analysis of debris flow gullies in Iceland. However the saw-tooth slope profile exhibited by gullies in La Gomera could provide a diagnostic feature to look for on Mars.