AbstractsEarth & Environmental Science

Debris flows on Mars: An experimental analysis

by L. Braat

Institution: Universiteit Utrecht
Year: 2014
Keywords: debris flow, alluvial fan, mars, experiments, morphology
Record ID: 1255921
Full text PDF: http://dspace.library.uu.nl:8080/handle/1874/301311


Morphological indications for debris flows on Mars were discovered by several authors since the discovery of gullies by Malin and Edgett in 2000. Although most processes related to debris flows are well understood, mechanisms that define dimensions of debris-flow deposits are still uncertain. The aim of this thesis is to find relations between debris-flow morphology and initial and boundary condition (volume, slope, angle, channel dimensions, sediment composition, water content and flow characteristics) by the use of small-scale experiments. These relations will be used to the gain information about Martian conditions. 206 debris-flow experiments were performed to develop a large dataset in which the sensitivity to different initial and boundary conditions was tested. Secondly, 3 alluvial fans were built by multiple debris flows to find more morphologic characteristics (fan slope, fan dimension, sorting patterns and debris-flow dimensions on the fan). Recognizable morphologies similar to the experiments were found on Martian fans strengthening the hypothesis that they were formed by debris flows. From comparison with the data it was found that the studied Martian debris flows contain approximately less than 6wt% clay, 10-30wt% coarse material and more than 27wt% water.