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| Titel |
Detection, mapping, classification, and statistics of mass movements on Mars |
| VerfasserIn |
Maria Teresa Brunetti, Goro Komatsu, Paolo Mancinelli, Kazuhisa Goto, Michele Santangelo, Hitoshi Saito, Federica Fiorucci, Mauro Cardinali, Fausto Guzzetti |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250050639
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| Zusammenfassung |
| On Earth, detection and mapping of landslides is obtained mainly through the visual analysis
of stereoscopic aerial photographs obtained at scales ranging from 1:5,000 to 1:75,000.
Alternatively, very-high-resolution monoscopic images taken by optical sensors onboard
satellite platforms can be used. The space-borne sensors have typically a spatial resolution of
1 meter or less for panchromatic mode, and of 5 meters or less for multispectral mode,
allowing for visual detection and mapping of the majority of slope failures on Earth.
Adopting a similar approach, and using the same visual interpretation criteria used by
geomorphologists to map terrestrial landslides, we have attempted to detect, map, and
classify landslides on Mars using monoscopic high and ultra-high-resolution imagery
obtained by (i) the High-Resolution Stereo Camera (HRSC) onboard Mars Express and (ii)
the HiRISE camera onboard Mars Reconnaissance Orbiter. These images have spatial
resolutions (up to ~ 30 cm for HiRISE and up to ~2 m for HRSC). These are sufficient
to detect and map mass movements on Mars with unprecedented spatial details,
allowing for compilation of nearly complete inventories, above a minimum size
threshold. In our preliminary work, using a THEMIS image mosaic with HRSC and
HiRISE images where available and MOLA-derived topography, we detected and
mapped 180 landslides (including escarpments, source areas, and deposits) in a
4Ã104 km2 area of the western section of the Valles Marineris rift system. Along the
slopes of this very prominent canyon with a local relief exceeding 7 km, we visually
identified a significantly larger number of slope failures than previously reported
(Quantin et al., 2004), with areas of the individual failures 1.3Ã105 < AL <
2.6Ã109m2. The obtained inventory is considered nearly complete for landslides with
AL > 1.5Ã106 m2. A further reconnaissance of the planetary surface through visual
analysis of the same mosaic of THEMIS images, and locally HRSC and HiRISE
images where available, allowed to detect and map several mass movements at other
locations, including: (i) scarps in Bahram and Nilokeras, (ii) along steep slopes of
some craters (e.g. Zunil crater), (iii) at the toe of Olympus Mons, and (iv) near
the planet’s north pole cap. Adopting a classification commonly used to classify
terrestrial mass movements, all the slope failures detected and mapped on Mars were
classified in six main types, including: slide, slide/flow, flow, debris flow, lateral
spread, and rock avalanche. Features similar to rock glaciers were also recognized
and mapped locally. For the Valles Marineris study area, for which a sufficiently
large inventory of mass movements was obtained, we determined the statistics of
landslide size, and we compared them to similar statistics available for terrestrial
landslides.
References
Quantin, C., Allemand, P., Delacourt, C.: Morphology and geometry of Valles Marineris
landslides. Planetary and Space Science 52, 1011–1022, 2004. |
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