HR: 11:35h
AN: P12C-02    [Abstracts]
TI: Martian Stepped Fans: Analysis of the apron and associated channel
AU: * Kraal, E
EM: ekraal@vt.edu
AF: Virginia Tech, 4044 Derring Hall (0420), Blacksburg, VA 24061, United States
AU: van Dijk, M
EM: mvandijk@geo.uu.nl
AF: Utrecht University, PO Box 80021, Utrecht, 3512LM, Netherlands
AU: Postma, G
EM: gpostma@geo.uu.nl
AF: Utrecht University, PO Box 80021, Utrecht, 3512LM, Netherlands
AU: Kleinhans, M
EM: m.kleinhans@geo.uu.nl
AF: Utrecht University, PO Box 80021, Utrecht, 3512LM, Netherlands
AB: Martian stepped fans have a distinctive terraced profile and are often fed by deep, first order canyons with small drainage basins. 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 and channel erosion 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.
DE: 1821 Floods
DE: 1825 Geomorphology: fluvial (1625)
DE: 1856 River channels (0483, 0744)
DE: 5415 Erosion and weathering
DE: 5419 Hydrology and fluvial processes
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting