Encyclopedia of Planetary Landforms

2015 Edition
| Editors: Henrik Hargitai, Ákos Kereszturi

Quasi-Circular Depression

  • Lauren Edgar
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-3134-3_288

Definition

A circular topographic depression that appears in a high-resolution topographic dataset but may not have a corresponding visual structure on the surface.

Synonyms

Description

In the broad sense, all kinds of at least somewhat circular depressions in the gridded topographic dataset of Mars Orbiter Laser Altimeters or Lunar Orbiter Laser Altimeter are quasi-circular depressions (QCDs), visible or not. In a more strict sense, QCDs (or stealth/invisible QCDs) are only those evident depressions which have no structural representation in optical imagery, i.e., cannot be detected via photogeologic methods (Buczkowski 2007b) (Fig. 1). However, some stealth QCDs (sQCDs) are manifested as circular fractures (Ghent et al. 2012).
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References

  1. Buczkowski DL (2007) Comparing Quasi-Circular Depression (QCD) locations to Northern Lowland materials on Mars. Seventh International Conference on Mars # 3302Google Scholar
  2. Buczkowski DL, McGill GE (2002) Topography within circular grabens: implications for polygon origin, Utopia Planitia, Mars. Geophys Res Lett 29(7):1155. doi:10.1029/2001GL014100CrossRefGoogle Scholar
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  11. Ghent RR, Anderson SW, Pithwala TM (2012) The formation of small cones in Isidis Planitia, Mars through mobilization of pyroclastic surge deposits. Icarus 217:169–183CrossRefGoogle Scholar
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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.U.S. Geological SurveyAstrogeology Science CenterFlagstaffUSA