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| Titel |
Two-dimensional numerical ice flow modelling of an empirically reconstructed martian glacier-like form |
| VerfasserIn |
Stephen Brough, Bryn Hubbard, Alun Hubbard |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250134819
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| Publikation (Nr.) |
 EGU/EGU2016-15587.pdf |
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| Zusammenfassung |
| Although a substantial reservoir of glacier ice has been identified in the mid-latitudes of
Mars, debate still persists regarding the formation, current and former extent, and dynamic
evolution of these ice masses. Here we present initial results from a higher-order,
two-dimensional (2D) numerical model of ice flow for an empirically reconstructed
glacier-like form (GLF), a distinctive ice related landform, similar in planform
appearance to valley or debris-covered glaciers on Earth, in eastern Hellas Planitia,
Mars (∼38.65 oS and 113.16 oE). The main aim of this study is to investigate the
long-term temperature requirement to yield surface ice flow rates consistent with
those recently reconstructed from boulder trails observed in a comparable GLF.
We apply our numerical model to the GLF’s central flowline under steady-state
conditions and vary the viscosity related rate factor parameter, A, for a range of
temperatures from 0 to -100 oC for our three reconstruction scenarios (lower [12
kPa], mean [22 kPa] and upper [38 kPa]; Karlsson et al. [2015] Geophys. Res. Lett.,
42[8]). The model converges for all realistic temperatures yielding a range of 2D
stress and strain configurations for our reconstructed GLF. The mean annual surface
velocities across the three reconstruction scenarios show a similar pattern, with
motion recorded at temperatures ranging from 0 oC to ∼ -70 oC, below which motion
reduces to <10-5 m a−1. In order to simulate flow rates to 7.5 mm a−1 (Hubbard et
al. [2014] The Cryosphere, 8), as determined for other martian GLFs, the model
experiments reveal a required ice temperature for the GLF of between ∼ -7.5 and -27 oC. |
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