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| Titel |
Hydraulic analysis of a Martian paleolake |
| VerfasserIn |
Emanuele Baratti, Maurizio Pajola, Sandro Rossato, Clara Mangili, Marcello Coradini, Alberto Montanari, Karen McBride |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105715
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| Publikation (Nr.) |
 EGU/EGU2015-5258.pdf |
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| Zusammenfassung |
| One of the most interesting morphological feature on the surface of Mars are paleolakes: time
capsules and low-energy depositional settings that preserve hints on the ancient environment
and, possibly, traces of life. On Earth, lakes host a huge diversity of habitats where life is
flourishing; hence, on Mars, they may have once supported life too. In order to understand the
paleohydrology of these basins, the estimation of the water discharge flowing into their
tributary and/or outlets can give important clues on the water cycle on the planet. On Mars,
the most common modeling used to reconstruct the hydraulic properties are based on the
adaptation of terrestrial empirical relationship, less focusing on more sophisticated hydraulic
models.
The main objective of this study is to separately analyze the hydraulic characteristics of
the tributary and the outlet of a paleolake located in the Menmonia quadrangle by using an
hydraulic model based on the energy and momentum equations of the body of water
enclosed in the channels. The lengths of the analyzed river reaches are ~ 10 km
and ~ 19 km, the outlet and the tributary respectively. A Monte Carlo procedure
coupled to geomorphological evidences of the paleowater surface (e.g. terraces levels)
were used to constrain the hydraulic parameters of the system. The Mars Express
High-resolution stereo camera digital elevation model, H31850000DA4 with a
spatial resolution on 75 m, is hence used to characterize the geometry of the study
area.
In this contribution we provide estimates on the magnitude of the bankfull discharge and
roughness coefficient of the tributary and the outlet of the paleolake; moreover, on the basis
of these results, the probable water depth of the lake is inferred. Finally, a discussion on the
possibility that the system inlet-lake-outlet was acting simultaneously is also presented.
Consequently, a sensitivity analysis is performed to examine the accuracy of the
results to the main sources of uncertainty concerning the methodology, as well as,
the uncertainty in the geomorphological evidences used to constrain the hydraulic
modelling.
Given the comparable discharge estimates of the tributary and the outlet, as well as the
coherent elevation and width of their mouths into the lake, the results suggest that both
channels were most probably acting simultaneously during their last evolutionary phase, with
a discharge equal to ~ 6000 m3s-1 and a water surface elevation in the lake equal to ~
-1400 m. This contribution supports the hypothesis of an ancient and articulated hydrologic
system acting in the study area. |
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