Widespread excess ice in Arcadia Planitia, Mars

Ali M. Bramson, Shane Byrne, Nathaniel E. Putzig, Sarah Sutton, Jeffrey J. Plaut, T. Charles Brothers, John W. Holt

Research output: Contribution to journalArticle

54 Scopus citations

Abstract

The distribution of subsurface water ice on Mars is a key constraint on past climate, while the volumetric concentration of buried ice (pore-filling versus excess) provides information about the process that led to its deposition. We investigate the subsurface of Arcadia Planitia by measuring the depth of terraces in simple impact craters and mapping a widespread subsurface reflection in radar sounding data. Assuming that the contrast in material strengths responsible for the terracing is the same dielectric interface that causes the radar reflection, we can combine these data to estimate the dielectric constant of the overlying material. We compare these results to a three-component dielectric mixing model to constrain composition. Our results indicate a widespread, decameters-thick layer that is excess water ice ∼10<sup>4</sup> km<sup>3</sup> in volume. The accumulation and long-term preservation of this ice is a challenge for current Martian climate models.

Original languageEnglish (US)
Pages (from-to)6566-6574
Number of pages9
JournalGeophysical Research Letters
Volume42
Issue number16
DOIs
StatePublished - Aug 28 2015

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Keywords

  • digital terrain models
  • layered subsurface
  • Mars midlatitude ice
  • spacecraft observations
  • subsurface radar
  • terraced craters

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Geophysics

Cite this

Bramson, A. M., Byrne, S., Putzig, N. E., Sutton, S., Plaut, J. J., Brothers, T. C., & Holt, J. W. (2015). Widespread excess ice in Arcadia Planitia, Mars. Geophysical Research Letters, 42(16), 6566-6574. https://doi.org/10.1002/2015GL064844