Origin of martian northern hemisphere mid-latitude lobate debris aprons

Han Li, Mark S. Robinson, Donna M. Jurdy

Research output: Contribution to journalArticle

53 Scopus citations

Abstract

Lobate debris aprons in the martian mid- to high-latitudes (northern and southern hemispheres) have been interpreted as ice-related features that indicate periglacial climate conditions as recently as late Amazonian. Using MOLA topographic profiles perpendicular to apron flow fronts, we surveyed 36 debris aprons in the northern hemisphere found in the regions of Mareotis, Protonilus, and Deuteronilus Mensae and Acheron Fossae. The profiles of these aprons were compared with idealized simple plastic and viscous power law models for ice-rock mixtures. All aprons studied exhibit convex profiles similar to a simple plastic model. This confirms previous interpretations that debris aprons are ice-rich mixtures with rheologies similar to stagnant ice sheets, thus indicating high ice concentrations (>40% by volume). About 60% of the surveyed debris apron population significantly deviates from the idealized simple plastic model profile; this may be due to locally reduced ice content, which primarily controls apron topography. Although post-emplacement modification due to near-surface ice sublimation plays a secondary role in defining the overall shape of aprons, it causes conspicuous surface textures. Degradation by ice sublimation probably results in pitted and ridge-and-furrow surface textures revealed by high resolution MOC images. Such textures may indicate decreased near-surface ice stability since the formation of the aprons, possibly due to Mars' current low obliquity after their emplacement. High ice content inferred from topography suggests some debris aprons have ice cores: potentially exploitable water resources for future robotic/human operations that could prove invaluable for missions remote from polar regions.

Original languageEnglish (US)
Pages (from-to)382-394
Number of pages13
JournalIcarus
Volume176
Issue number2
DOIs
StatePublished - Aug 1 2005
Externally publishedYes

    Fingerprint

Keywords

  • Climate
  • Geological processes
  • Geomorphology
  • Mars
  • Surface

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this