T93 Evidence of Climatic and Tectonic Change Recorded in Alluvial Fans
Monday, 29 October 2007
1:30 PM - 5:30 PM
MARTIAN STEPPED FANS RECORD RAPID WATER RELEASE
Paper number: T93-11
Program: Technical Sessions
Time: 4:10 PM – 4:25 PM
Authors
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Maurits van DijkUtrecht University, Utrecht, N/A
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George PostmaUtrecht University, Utrecht, N/A
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M.G. KleinhansUtrecht University, Utrecht, N/A
Abstract
Martian stepped fans have a distinctive terraced profile. Using flume experiments, we find that distinct terraces form as a fan deposits into a crater basin filling with water. Terrace preservation implies no long-term deposition at a stable water level and an inactive fluvial system during water drainage. Based on scaling from our experiments, we estimate that the formation time for Martian stepped-fans is on the order of decades and conclude that stepped fans on Mars likely formed during a single, basin-filling event driven by a short-lived, intense hydrologic cycle. The estimated discharge rates are comparable to some of the largest rivers on Earth and these rates highlight the challenges of determining the water source.