HR: 1340h
AN: P13A-0988    [Abstracts]
TI: Lobate Debris Aprons in the Hellas Planitia Region, Mars: Insights from High-Resolution Data from the HRSC Experiment on Mars Express
AU: * van Gasselt, S
EM: vgasselt@zedat.fu-berlin.de
AF: Institute of Geosciences, Freie Universitaet Berlin, Malteserstr. 74-100, Berlin, D-12249 Germany
AU: Hauber, E
EM: ernst.hauber@dlr.de
AF: Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstr. 2, Berlin, D-12489 Germany
AU: Reiss, D
EM: dennis.reiss@dlr.de
AF: Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstr. 2, Berlin, D-12489 Germany
AU: Neukum, G
EM: gneukum@zedat.fu-berlin.de
AF: Institute of Geosciences, Freie Universitaet Berlin, Malteserstr. 74-100, Berlin, D-12249 Germany
AB: A variety of landforms indicates the possible existence of past or present ice in the near subsurface of Mars. Among the most spectacular ice-related features are lobate debris aprons (LDA). They have been interpreted to be a mixture of rock particles and interstitial ice analogous to terrestrial rock glaciers (debris transport systems comprising a creeping mixture of rock and segregational or interstitial ice). Rock glaciers are indicators for the climatic environment during their formation. The analogy between terrestrial rock glaciers and Martian LDA is predominantly based upon the shape of debris aprons, their surface texture, their relationship to adjacent regions with permafrost-related morphologies, and the correlation of their global distribution with the predicted stability of Martian ground ice. LDA are known from the dichotomy boundary and from regions surrounding the large impact basins of the southern hemisphere. This work focusses on the distribution of LDA in the circum-Hellas Planitia region and compares morphometric results as well as mapping results of the textural context between MOLA/Viking/MOC data and the data obtained by the High Resolution Stereo Camera (HRSC) on Mars Express. The HRSC has obtained colour and stereo information with a resolution of 11 metres at its best from 35 orbits over the northern and eastern impact basin region (01/09/2004 - 06/28/2004). The vertical accuracy of the derived digital terrain data is comparable to MOLA-derived products but several regions are of such a good photogrammetric quality that elevation model of at least 100~m per pixels could have been obtained. First results of morphometry in the Hellas Planitia region fit perfectly into the MOLA/Viking derived area and volume ratios and are consistent with terrestrial measurements of mountainous debris transport systems. The data obtained so far fill the morphometric gap in the smaller-sized distribution of remnants and debris aprons.
DE: 5416 Glaciation
DE: 5460 Physical properties of materials
DE: 5494 Instruments and techniques
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting